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The following commit(s) were added to refs/heads/master by this push:
new d450f5c Add support for Litex VexRiscV.
d450f5c is described below
commit d450f5ce778c32e36775ebc04e3f93288c5f857a
Author: aenrbes <[email protected]>
AuthorDate: Sat Mar 21 14:01:56 2020 +0800
Add support for Litex VexRiscV.
---
arch/risc-v/Kconfig | 10 +
arch/risc-v/include/litex/chip.h | 24 +
arch/risc-v/include/litex/irq.h | 113 ++++
arch/risc-v/src/litex/Kconfig | 28 +
arch/risc-v/src/litex/Make.defs | 49 ++
arch/risc-v/src/litex/chip.h | 32 +
arch/risc-v/src/litex/hardware/litex_clint.h | 32 +
arch/risc-v/src/litex/hardware/litex_memorymap.h | 38 ++
arch/risc-v/src/litex/hardware/litex_plic.h | 34 +
arch/risc-v/src/litex/hardware/litex_uart.h | 48 ++
arch/risc-v/src/litex/litex.h | 38 ++
arch/risc-v/src/litex/litex_allocateheap.c | 41 ++
arch/risc-v/src/litex/litex_clockconfig.c | 63 ++
arch/risc-v/src/litex/litex_clockconfig.h | 65 ++
arch/risc-v/src/litex/litex_config.h | 54 ++
arch/risc-v/src/litex/litex_head.S | 204 ++++++
arch/risc-v/src/litex/litex_idle.c | 67 ++
arch/risc-v/src/litex/litex_irq.c | 263 ++++++++
arch/risc-v/src/litex/litex_irq_dispatch.c | 126 ++++
arch/risc-v/src/litex/litex_lowputc.c | 124 ++++
arch/risc-v/src/litex/litex_lowputc.h | 59 ++
arch/risc-v/src/litex/litex_memorymap.h | 48 ++
arch/risc-v/src/litex/litex_serial.c | 764 ++++++++++++++++++++++
arch/risc-v/src/litex/litex_start.c | 125 ++++
arch/risc-v/src/litex/litex_timerisr.c | 202 ++++++
arch/risc-v/src/litex/litex_vectors.S | 42 ++
arch/risc-v/src/litex/up_schedulesigaction.c | 192 ++++++
boards/Kconfig | 11 +
boards/risc-v/litex/arty_a7/Kconfig | 8 +
boards/risc-v/litex/arty_a7/README.txt | 28 +
boards/risc-v/litex/arty_a7/configs/nsh/defconfig | 74 +++
boards/risc-v/litex/arty_a7/include/board.h | 68 ++
boards/risc-v/litex/arty_a7/scripts/Make.defs | 96 +++
boards/risc-v/litex/arty_a7/scripts/ld.script | 93 +++
boards/risc-v/litex/arty_a7/src/Makefile | 29 +
boards/risc-v/litex/arty_a7/src/arty_a7.h | 32 +
boards/risc-v/litex/arty_a7/src/litex_appinit.c | 75 +++
boards/risc-v/litex/arty_a7/src/litex_boot.c | 57 ++
boards/risc-v/litex/arty_a7/src/litex_bringup.c | 61 ++
boards/risc-v/litex/drivers/Kconfig | 4 +
40 files changed, 3521 insertions(+)
diff --git a/arch/risc-v/Kconfig b/arch/risc-v/Kconfig
index 0e601a1..c7a4115 100644
--- a/arch/risc-v/Kconfig
+++ b/arch/risc-v/Kconfig
@@ -26,6 +26,12 @@ config ARCH_CHIP_K210
---help---
Kendryte K210 processor (RISC-V 64bit core with GC extensions)
+config ARCH_CHIP_LITEX
+ bool "Enjoy Digital LITEX VEXRISCV"
+ select ARCH_RV32IM
+ ---help---
+ Enjoy Digital LITEX VEXRISCV softcore processor (RV32IMA).
+
config ARCH_CHIP_NR5
bool "NEXT NanoRisc5"
select ARCH_RV32IM
@@ -62,6 +68,7 @@ config ARCH_CHIP
string
default "fe310" if ARCH_CHIP_FE310
default "k210" if ARCH_CHIP_K210
+ default "litex" if ARCH_CHIP_LITEX
default "nr5m100" if ARCH_CHIP_NR5
default "gap8" if ARCH_CHIP_GAP8
@@ -87,6 +94,9 @@ endif
if ARCH_CHIP_K210
source arch/risc-v/src/k210/Kconfig
endif
+if ARCH_CHIP_LITEX
+source arch/risc-v/src/litex/Kconfig
+endif
if ARCH_CHIP_NR5
source arch/risc-v/src/nr5m100/Kconfig
endif
diff --git a/arch/risc-v/include/litex/chip.h b/arch/risc-v/include/litex/chip.h
new file mode 100644
index 0000000..5072b88
--- /dev/null
+++ b/arch/risc-v/include/litex/chip.h
@@ -0,0 +1,24 @@
+/****************************************************************************
+ * arch/risc-v/include/litex/chip.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_INCLUDE_LITEX_CHIP_H
+#define __ARCH_RISCV_INCLUDE_LITEX_CHIP_H
+
+#endif /* __ARCH_RISCV_INCLUDE_LITEX_CHIP_H */
diff --git a/arch/risc-v/include/litex/irq.h b/arch/risc-v/include/litex/irq.h
new file mode 100644
index 0000000..c2f5e0c
--- /dev/null
+++ b/arch/risc-v/include/litex/irq.h
@@ -0,0 +1,113 @@
+/****************************************************************************
+ * arch/risc-v/include/litex/irq.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_INCLUDE_LITEX_IRQ_H
+#define __ARCH_RISCV_INCLUDE_LITEX_IRQ_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <arch/irq.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* In mstatus register */
+
+#define MSTATUS_MIE (0x1 << 3) /* Machine Interrupt Enable */
+#define MSTATUS_MPIE (0x1 << 7) /* Machine Previous Interrupt Enable */
+#define MSTATUS_MPPM (0x3 << 11) /* Machine Previous Privilege (m-mode) */
+
+/* In mie (machine interrupt enable) register */
+
+#define MIE_MSIE (0x1 << 3) /* Machine Software Interrupt Enable */
+#define MIE_MTIE (0x1 << 7) /* Machine Timer Interrupt Enable */
+#define MIE_MEIE (0x1 << 11) /* Machine External Interrupt Enable */
+#define MIP_MTIP (1 << 7)
+
+/* Map RISC-V exception code to NuttX IRQ */
+
+/* IRQ 0-15 : (exception:interrupt=0) */
+
+#define LITEX_IRQ_IAMISALIGNED (0) /* Instruction Address Misaligned */
+#define LITEX_IRQ_IAFAULT (1) /* Instruction Address Fault */
+#define LITEX_IRQ_IINSTRUCTION (2) /* Illegal Instruction */
+#define LITEX_IRQ_BPOINT (3) /* Break Point */
+#define LITEX_IRQ_LAMISALIGNED (4) /* Load Address Misaligned */
+#define LITEX_IRQ_LAFAULT (5) /* Load Access Fault */
+#define LITEX_IRQ_SAMISALIGNED (6) /* Store/AMO Address Misaligned */
+#define LITEX_IRQ_SAFAULT (7) /* Store/AMO Access Fault */
+#define LITEX_IRQ_ECALLU (8) /* Environment Call from U-mode */
+ /* 9-10: Reserved */
+
+#define LITEX_IRQ_ECALLM (11) /* Environment Call from M-mode */
+ /* 12-15: Reserved */
+
+/* IRQ 16- : (async event:interrupt=1) */
+
+#define LITEX_IRQ_ASYNC (16)
+#define LITEX_IRQ_MSOFT (LITEX_IRQ_ASYNC + 3) /* Machine Software Int */
+#define LITEX_IRQ_MTIMER (LITEX_IRQ_ASYNC + 7) /* Machine Timer Int */
+#define LITEX_IRQ_MEXT (LITEX_IRQ_ASYNC + 11) /* Machine External Int */
+
+/* Machine Global External Interrupt */
+
+#define LITEX_IRQ_UART0 (LITEX_IRQ_MEXT + 1)
+#define LITEX_IRQ_TIMER0 (LITEX_IRQ_MEXT + 2)
+
+/* Total number of IRQs */
+
+#define NR_IRQS (LITEX_IRQ_TIMER0 + 1)
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+EXTERN irqstate_t up_irq_save(void);
+EXTERN void up_irq_restore(irqstate_t);
+EXTERN irqstate_t up_irq_enable(void);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_RISCV_INCLUDE_LITEX_IRQ_H */
diff --git a/arch/risc-v/src/litex/Kconfig b/arch/risc-v/src/litex/Kconfig
new file mode 100644
index 0000000..d6b7e3b
--- /dev/null
+++ b/arch/risc-v/src/litex/Kconfig
@@ -0,0 +1,28 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+comment "LITEX Configuration Options"
+
+menu "LITEX Peripheral Support"
+
+# These "hidden" settings determine is a peripheral option is available for the
+# selection MCU
+
+config LITEX_HAVE_UART0
+ bool
+ default y
+ select UART0_SERIALDRIVER
+ select ARCH_HAVE_SERIAL_TERMIOS
+
+# These are the peripheral selections proper
+
+config LITEX_UART0
+ bool "UART0"
+ default y
+ select ARCH_HAVE_UART0
+ select ARCH_HAVE_SERIAL_TERMIOS
+ select LITEX_UART
+
+endmenu
diff --git a/arch/risc-v/src/litex/Make.defs b/arch/risc-v/src/litex/Make.defs
new file mode 100644
index 0000000..7a49f3f
--- /dev/null
+++ b/arch/risc-v/src/litex/Make.defs
@@ -0,0 +1,49 @@
+############################################################################
+# arch/risc-v/src/litex/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+# Specify our HEAD assembly file. This will be linked as
+# the first object file, so it will appear at address 0
+HEAD_ASRC = litex_vectors.S
+
+# Specify our general Assembly files
+CHIP_ASRCS = litex_head.S up_syscall.S
+
+# Specify C code within the common directory to be included
+CMN_CSRCS += up_initialize.c up_swint.c
+CMN_CSRCS += up_allocateheap.c up_createstack.c up_exit.c
+CMN_CSRCS += up_assert.c up_blocktask.c up_copystate.c up_initialstate.c
+CMN_CSRCS += up_interruptcontext.c up_modifyreg32.c up_puts.c up_mdelay.c
+CMN_CSRCS += up_releasepending.c up_reprioritizertr.c
+CMN_CSRCS += up_releasestack.c up_stackframe.c up_schedulesigaction.c
+CMN_CSRCS += up_sigdeliver.c up_udelay.c up_unblocktask.c up_usestack.c
+
+ifeq ($(CONFIG_STACK_COLORATION),y)
+CMN_CSRCS += up_checkstack.c
+endif
+
+ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
+CMN_CSRCS += up_vfork.c
+endif
+
+# Specify our C code within this directory to be included
+CHIP_CSRCS = litex_allocateheap.c litex_clockconfig.c
+CHIP_CSRCS += litex_idle.c litex_irq.c litex_irq_dispatch.c
+CHIP_CSRCS += litex_lowputc.c litex_serial.c
+CHIP_CSRCS += litex_start.c litex_timerisr.c
diff --git a/arch/risc-v/src/litex/chip.h b/arch/risc-v/src/litex/chip.h
new file mode 100644
index 0000000..228cda5
--- /dev/null
+++ b/arch/risc-v/src/litex/chip.h
@@ -0,0 +1,32 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/chip.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_CHIP_H
+#define __ARCH_RISCV_SRC_LITEX_CHIP_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "litex_memorymap.h"
+
+#endif /* __ARCH_RISCV_SRC_LITEX_CHIP_H */
diff --git a/arch/risc-v/src/litex/hardware/litex_clint.h
b/arch/risc-v/src/litex/hardware/litex_clint.h
new file mode 100644
index 0000000..73ff1a6
--- /dev/null
+++ b/arch/risc-v/src/litex/hardware/litex_clint.h
@@ -0,0 +1,32 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/hardware/litex_clint.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_CLINT_H
+#define __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_CLINT_H
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define LITEX_CLINT_LATCH (LITEX_CPUTIMER_BASE)
+#define LITEX_CLINT_MTIME (LITEX_CPUTIMER_BASE + 0x04)
+#define LITEX_CLINT_MTIMECMP (LITEX_CPUTIMER_BASE + 0x24)
+
+#endif /* __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_CLINT_H */
diff --git a/arch/risc-v/src/litex/hardware/litex_memorymap.h
b/arch/risc-v/src/litex/hardware/litex_memorymap.h
new file mode 100644
index 0000000..f5b208c
--- /dev/null
+++ b/arch/risc-v/src/litex/hardware/litex_memorymap.h
@@ -0,0 +1,38 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/hardware/litex_memorymap.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_MEMORYMAP_H
+#define __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_MEMORYMAP_H
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Register Base Address ****************************************************/
+
+/* litex vexRiscv does not follow RISC-V privileged specification and
+ * uses two additional CSRs: mask and pending.
+ */
+
+#define LITEX_CPUTIMER_BASE 0xf0000800 /* riscv clint timer */
+#define LITEX_TIMER0_BASE 0xf0001800
+#define LITEX_UART0_BASE 0xf0001000 /* 0xf0001000 - : UART0 */
+
+#endif /* __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_MEMORYMAP_H */
diff --git a/arch/risc-v/src/litex/hardware/litex_plic.h
b/arch/risc-v/src/litex/hardware/litex_plic.h
new file mode 100644
index 0000000..bd9e100
--- /dev/null
+++ b/arch/risc-v/src/litex/hardware/litex_plic.h
@@ -0,0 +1,34 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/hardware/litex_plic.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_PLIC_H
+#define __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_PLIC_H
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* litex vexRiscv does not follow RISC-V privileged specification and
+ * uses two additional CSRs: mask and pending.
+ */
+#define LITEX_MMASK_CSR 0xBC0
+#define LITEX_MPENDING_CSR 0xFC0
+
+#endif /* __ARCH_RISCV_SRC_LITEX_HARDWARE_LITEX_PLIC_H */
diff --git a/arch/risc-v/src/litex/hardware/litex_uart.h
b/arch/risc-v/src/litex/hardware/litex_uart.h
new file mode 100644
index 0000000..f6affba
--- /dev/null
+++ b/arch/risc-v/src/litex/hardware/litex_uart.h
@@ -0,0 +1,48 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/hardware/litex_uart.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef ARCH_RISCV_SRC_LITEX_CHIP_LITEX_UART_H
+#define ARCH_RISCV_SRC_LITEX_CHIP_LITEX_UART_H
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define UART_RXTX_OFFSET 0x00
+#define UART_TXFULL_OFFSET 0x04
+#define UART_RXEMPTY_OFFSET 0x08
+#define UART_EV_STATUS_OFFSET 0x0c
+#define UART_EV_PENDING_OFFSET 0x10
+#define UART_EV_ENABLE_OFFSET 0x14
+
+#ifdef CONFIG_LITEX_UART0
+# define LITEX_UART0_RXTX (LITEX_UART0_BASE + UART_RXTX_OFFSET)
+# define LITEX_UART0_TXFULL (LITEX_UART0_BASE + UART_TXFULL_OFFSET)
+# define LITEX_UART0_RXEMPTY (LITEX_UART0_BASE + UART_RXEMPTY_OFFSET)
+# define LITEX_UART0_EV_STATUS (LITEX_UART0_BASE + UART_EV_STATUS_OFFSET)
+# define LITEX_UART0_EV_PENDING (LITEX_UART0_BASE + UART_EV_PENDING_OFFSET)
+# define LITEX_UART0_EV_ENABLE (LITEX_UART0_BASE + UART_EV_ENABLE_OFFSET)
+# define LITEX_UART0_PHY_TUNING_WORD 0xf0002000L
+#endif
+
+#define UART_EV_TX 0x1
+#define UART_EV_RX 0x2
+
+#endif /* _ARCH_RISCV_SRC_LITEX_CHIP_LITEX_UART_H */
diff --git a/arch/risc-v/src/litex/litex.h b/arch/risc-v/src/litex/litex.h
new file mode 100644
index 0000000..70c4fa8
--- /dev/null
+++ b/arch/risc-v/src/litex/litex.h
@@ -0,0 +1,38 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_LITEX_H
+#define __ARCH_RISCV_SRC_LITEX_LITEX_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <arch/irq.h>
+#include "up_internal.h"
+#include "chip.h"
+#include "litex_lowputc.h"
+
+#endif /* __ARCH_RISCV_SRC_LITEX_LITEX_H */
diff --git a/arch/risc-v/src/litex/litex_allocateheap.c
b/arch/risc-v/src/litex/litex_allocateheap.c
new file mode 100644
index 0000000..2edc5ba
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_allocateheap.c
@@ -0,0 +1,41 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_allocateheap.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <arch/board/board.h>
+
+#include "litex.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_addregion
+ ****************************************************************************/
+
+void up_addregion(void)
+{
+}
diff --git a/arch/risc-v/src/litex/litex_clockconfig.c
b/arch/risc-v/src/litex/litex_clockconfig.c
new file mode 100644
index 0000000..5622ae0
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_clockconfig.c
@@ -0,0 +1,63 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_clockconfig.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <arch/board/board.h>
+
+#include "up_arch.h"
+#include "litex_clockconfig.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: litex_get_hfclk
+ ****************************************************************************/
+
+uint32_t litex_get_hfclk(void)
+{
+ /* fpga fabric default sys frequency */
+
+ return 100000000UL;
+}
+
+/****************************************************************************
+ * Name: litex_clockconfig
+ ****************************************************************************/
+
+void litex_clockconfig(void)
+{
+ /* pll is set by fpga fabric */
+}
diff --git a/arch/risc-v/src/litex/litex_clockconfig.h
b/arch/risc-v/src/litex/litex_clockconfig.h
new file mode 100644
index 0000000..4ef11b2
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_clockconfig.h
@@ -0,0 +1,65 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_clockconfig.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_LITEX_CLOCKCONFIG_H
+#define __ARCH_RISCV_SRC_LITEX_LITEX_CLOCKCONFIG_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include "litex_memorymap.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+EXTERN uint32_t litex_get_hfclk(void);
+EXTERN void litex_clockconfig(void);
+
+#if defined(__cplusplus)
+}
+#endif
+#undef EXTERN
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_RISCV_SRC_LITEX_LITEX_CLOCKCONFIG_H */
diff --git a/arch/risc-v/src/litex/litex_config.h
b/arch/risc-v/src/litex/litex_config.h
new file mode 100644
index 0000000..91b871f
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_config.h
@@ -0,0 +1,54 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_config.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_LITEX_CONFIG_H
+#define __ARCH_RISCV_SRC_LITEX_LITEX_CONFIG_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <arch/chip/chip.h>
+#include <arch/board/board.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#undef HAVE_UART_DEVICE
+#if defined(CONFIG_LITEX_UART0) || defined(CONFIG_LITEX_UART1)
+# define HAVE_UART_DEVICE 1
+#endif
+
+#if defined(CONFIG_UART0_SERIAL_CONSOLE) && defined(CONFIG_LITEX_UART0)
+# undef CONFIG_UART1_SERIAL_CONSOLE
+# define HAVE_SERIAL_CONSOLE 1
+#elif defined(CONFIG_UART1_SERIAL_CONSOLE) && defined(CONFIG_LITEX_UART1)
+# undef CONFIG_UART0_SERIAL_CONSOLE
+# define HAVE_SERIAL_CONSOLE 1
+#else
+# undef CONFIG_UART0_SERIAL_CONSOLE
+# undef CONFIG_UART1_SERIAL_CONSOLE
+# undef HAVE_SERIAL_CONSOLE
+#endif
+
+#endif /* __ARCH_RISCV_SRC_LITEX_LITEX_CONFIG_H */
diff --git a/arch/risc-v/src/litex/litex_head.S
b/arch/risc-v/src/litex/litex_head.S
new file mode 100644
index 0000000..bcfb0f8
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_head.S
@@ -0,0 +1,204 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_head.S
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <arch/rv32im/irq.h>
+
+#include "chip.h"
+
+/****************************************************************************
+ * Public Symbols
+ ****************************************************************************/
+
+ .global exception_common
+
+ /* Imported symbols */
+
+ .extern __trap_vec
+
+ .section .text
+ .global __start
+
+__start:
+
+ /* Set stack pointer to the idle thread stack */
+
+ lui sp, %hi(LITEX_IDLESTACK_TOP)
+ addi sp, sp, %lo(LITEX_IDLESTACK_TOP)
+
+ /* Disable all interrupts (i.e. timer, external) in mie */
+
+ csrw mie, zero
+
+ /* Initialize the Machine Trap Vector */
+
+ lui t0, %hi(__trap_vec)
+ addi t0, t0, %lo(__trap_vec)
+ csrw mtvec, t0
+
+ /* Jump to __litex_start */
+
+ jal x1, __litex_start
+
+ /* We shouldn't return from __litex_start */
+
+ .global _init
+ .global _fini
+
+_init:
+_fini:
+
+ /* These don't have to do anything since we use init_array/fini_array. */
+
+ ret
+
+/****************************************************************************
+ * Name: exception_common
+ ****************************************************************************/
+
+exception_common:
+
+ addi sp, sp, -XCPTCONTEXT_SIZE
+
+ sw x1, 1*4(sp) /* ra */
+ sw x3, 3*4(sp) /* gp */
+ sw x4, 4*4(sp) /* tp */
+ sw x5, 5*4(sp) /* t0 */
+ sw x6, 6*4(sp) /* t1 */
+ sw x7, 7*4(sp) /* t2 */
+ sw x8, 8*4(sp) /* s0 */
+ sw x9, 9*4(sp) /* s1 */
+ sw x10, 10*4(sp) /* a0 */
+ sw x11, 11*4(sp) /* a1 */
+ sw x12, 12*4(sp) /* a2 */
+ sw x13, 13*4(sp) /* a3 */
+ sw x14, 14*4(sp) /* a4 */
+ sw x15, 15*4(sp) /* a5 */
+ sw x16, 16*4(sp) /* a6 */
+ sw x17, 17*4(sp) /* a7 */
+ sw x18, 18*4(sp) /* s2 */
+ sw x19, 19*4(sp) /* s3 */
+ sw x20, 20*4(sp) /* s4 */
+ sw x21, 21*4(sp) /* s5 */
+ sw x22, 22*4(sp) /* s6 */
+ sw x23, 23*4(sp) /* s7 */
+ sw x24, 24*4(sp) /* s8 */
+ sw x25, 25*4(sp) /* s9 */
+ sw x26, 26*4(sp) /* s10 */
+ sw x27, 27*4(sp) /* s11 */
+ sw x28, 28*4(sp) /* t3 */
+ sw x29, 29*4(sp) /* t4 */
+ sw x30, 30*4(sp) /* t5 */
+ sw x31, 31*4(sp) /* t6 */
+
+ csrr s0, mstatus
+ sw s0, 32*4(sp) /* mstatus */
+
+ addi s0, sp, XCPTCONTEXT_SIZE
+ sw s0, 2*4(sp) /* original SP */
+
+ /* Setup arg0(exception cause), arg1(context) */
+
+ csrr a0, mcause /* exception cause */
+ csrr s0, mepc
+ sw s0, 0(sp) /* exception PC */
+
+ mv a1, sp /* context = sp */
+
+#if CONFIG_ARCH_INTERRUPTSTACK > 3
+ /* Switch to interrupt stack */
+
+ lui sp, %hi(g_intstackbase)
+ addi sp, sp, %lo(g_intstackbase)
+#endif
+
+ /* Call interrupt handler in C */
+
+ jal x1, litex_dispatch_irq
+
+ /* If context switch is needed, return a new sp */
+
+ mv sp, a0
+ lw s0, 0(sp) /* restore mepc */
+ csrw mepc, s0
+
+ lw s0, 32*4(sp) /* restore mstatus */
+ csrw mstatus, s0
+
+ lw x3, 3*4(sp) /* gp */
+ lw x4, 4*4(sp) /* tp */
+ lw x5, 5*4(sp) /* t0 */
+ lw x6, 6*4(sp) /* t1 */
+ lw x7, 7*4(sp) /* t2 */
+ lw x8, 8*4(sp) /* s0 */
+ lw x9, 9*4(sp) /* s1 */
+ lw x10, 10*4(sp) /* a0 */
+ lw x11, 11*4(sp) /* a1 */
+ lw x12, 12*4(sp) /* a2 */
+ lw x13, 13*4(sp) /* a3 */
+ lw x14, 14*4(sp) /* a4 */
+ lw x15, 15*4(sp) /* a5 */
+ lw x16, 16*4(sp) /* a6 */
+ lw x17, 17*4(sp) /* a7 */
+ lw x18, 18*4(sp) /* s2 */
+ lw x19, 19*4(sp) /* s3 */
+ lw x20, 20*4(sp) /* s4 */
+ lw x21, 21*4(sp) /* s5 */
+ lw x22, 22*4(sp) /* s6 */
+ lw x23, 23*4(sp) /* s7 */
+ lw x24, 24*4(sp) /* s8 */
+ lw x25, 25*4(sp) /* s9 */
+ lw x26, 26*4(sp) /* s10 */
+ lw x27, 27*4(sp) /* s11 */
+ lw x28, 28*4(sp) /* t3 */
+ lw x29, 29*4(sp) /* t4 */
+ lw x30, 30*4(sp) /* t5 */
+ lw x31, 31*4(sp) /* t6 */
+
+ lw x1, 1*4(sp) /* ra */
+
+ lw sp, 2*4(sp) /* restore original sp */
+
+ /* Return from Machine Interrupt */
+
+ mret
+
+/************************************************************************************
+ * Name: g_intstackalloc and g_intstackbase
+
************************************************************************************/
+
+#if CONFIG_ARCH_INTERRUPTSTACK > 3
+ .bss
+ .align 4
+ .global g_intstackalloc
+ .global g_intstackbase
+ .type g_intstackalloc, object
+ .type g_intstackbase, object
+g_intstackalloc:
+ .skip ((CONFIG_ARCH_INTERRUPTSTACK & ~3))
+g_intstackbase:
+ .skip 4
+ .size g_intstackbase, 4
+ .size g_intstackalloc, (CONFIG_ARCH_INTERRUPTSTACK & ~3)
+#endif
diff --git a/arch/risc-v/src/litex/litex_idle.c
b/arch/risc-v/src/litex/litex_idle.c
new file mode 100644
index 0000000..b94230a
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_idle.c
@@ -0,0 +1,67 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_idle.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+#include "up_internal.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_idle
+ *
+ * Description:
+ * up_idle() is the logic that will be executed when their is no other
+ * ready-to-run task. This is processor idle time and will continue until
+ * some interrupt occurs to cause a context switch from the idle task.
+ *
+ * Processing in this state may be processor-specific. e.g., this is where
+ * power management operations might be performed.
+ *
+ ****************************************************************************/
+
+void up_idle(void)
+{
+#if defined(CONFIG_SUPPRESS_INTERRUPTS) || defined(CONFIG_SUPPRESS_TIMER_INTS)
+ /* If the system is idle and there are no timer interrupts, then process
+ * "fake" timer interrupts. Hopefully, something will wake up.
+ */
+
+ nxsched_process_timer();
+#else
+
+ /* This would be an appropriate place to put some MCU-specific logic to
+ * sleep in a reduced power mode until an interrupt occurs to save power
+ */
+
+ asm("WFI");
+
+#endif
+}
diff --git a/arch/risc-v/src/litex/litex_irq.c
b/arch/risc-v/src/litex/litex_irq.c
new file mode 100644
index 0000000..0df390b
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_irq.c
@@ -0,0 +1,263 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_irq.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <stdio.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/board.h>
+#include <arch/irq.h>
+#include <arch/board/board.h>
+
+#include "up_internal.h"
+#include "up_arch.h"
+
+#include "litex.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_irqinitialize
+ ****************************************************************************/
+
+void up_irqinitialize(void)
+{
+ /* Disable Machine interrupts */
+
+ up_irq_save();
+
+ /* Disable all global interrupts */
+
+ asm volatile ("csrw %0, %1" :: "i"(LITEX_MMASK_CSR), "r"(0));
+
+ /* Colorize the interrupt stack for debug purposes */
+
+#if defined(CONFIG_STACK_COLORATION) && CONFIG_ARCH_INTERRUPTSTACK > 3
+ size_t intstack_size = (CONFIG_ARCH_INTERRUPTSTACK & ~3);
+ up_stack_color((FAR void *)((uintptr_t)&g_intstackbase - intstack_size),
+ intstack_size);
+#endif
+
+ /* litex vexriscv dont have priority and threshold control */
+
+ /* currents_regs is non-NULL only while processing an interrupt */
+
+ g_current_regs = NULL;
+
+ /* Attach the ecall interrupt handler */
+
+ irq_attach(LITEX_IRQ_ECALLM, up_swint, NULL);
+
+#ifndef CONFIG_SUPPRESS_INTERRUPTS
+
+ /* And finally, enable interrupts */
+
+ up_irq_enable();
+#endif
+}
+
+/****************************************************************************
+ * Name: up_disable_irq
+ *
+ * Description:
+ * Disable the IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+void up_disable_irq(int irq)
+{
+ int extirq;
+ int mask;
+ uint32_t oldstat;
+
+ if (irq == LITEX_IRQ_MSOFT)
+ {
+ /* Read mstatus & clear machine software interrupt enable in mie */
+
+ asm volatile ("csrrc %0, mie, %1": "=r" (oldstat) : "r"(MIE_MSIE));
+ }
+ else if (irq == LITEX_IRQ_MTIMER)
+ {
+ /* Read mstatus & clear machine timer interrupt enable in mie */
+
+ asm volatile ("csrrc %0, mie, %1": "=r" (oldstat) : "r"(MIE_MTIE));
+ }
+ else if (irq > LITEX_IRQ_MEXT)
+ {
+ extirq = irq - LITEX_IRQ_MEXT;
+ extirq--;
+
+ /* Clear enable bit for the irq */
+
+ if (0 <= extirq && extirq <= 31)
+ {
+ asm volatile ("csrr %0, %1" : "=r"(mask) : "i"(LITEX_MMASK_CSR));
+ mask &= ~(1 << extirq);
+ asm volatile ("csrw %0, %1" :: "i"(LITEX_MMASK_CSR), "r"(mask));
+ }
+ else
+ {
+ ASSERT(false);
+ }
+ }
+}
+
+/****************************************************************************
+ * Name: up_enable_irq
+ *
+ * Description:
+ * Enable the IRQ specified by 'irq'
+ *
+ ****************************************************************************/
+
+void up_enable_irq(int irq)
+{
+ int extirq;
+ int mask;
+ uint32_t oldstat;
+
+ if (irq == LITEX_IRQ_MSOFT)
+ {
+ /* Read mstatus & set machine software interrupt enable in mie */
+
+ asm volatile ("csrrs %0, mie, %1": "=r" (oldstat) : "r"(MIE_MSIE));
+ }
+ else if (irq == LITEX_IRQ_MTIMER)
+ {
+ /* Read mstatus & set machine timer interrupt enable in mie */
+
+ asm volatile ("csrrs %0, mie, %1": "=r" (oldstat) : "r"(MIE_MTIE));
+ }
+ else if (irq > LITEX_IRQ_MEXT)
+ {
+ extirq = irq - LITEX_IRQ_MEXT;
+ extirq--;
+
+ /* Set enable bit for the irq */
+
+ if (0 <= extirq && extirq <= 31)
+ {
+ asm volatile ("csrr %0, %1" : "=r"(mask) : "i"(LITEX_MMASK_CSR));
+ mask |= (1 << extirq);
+ asm volatile ("csrw %0, %1" :: "i"(LITEX_MMASK_CSR), "r"(mask));
+ }
+ else
+ {
+ ASSERT(false);
+ }
+ }
+}
+
+/****************************************************************************
+ * Name: up_get_newintctx
+ *
+ * Description:
+ * Return initial mstatus when a task is created.
+ *
+ ****************************************************************************/
+
+uint32_t up_get_newintctx(void)
+{
+ /* Set machine previous privilege mode to machine mode.
+ * Also set machine previous interrupt enable
+ */
+
+ return (MSTATUS_MPPM | MSTATUS_MPIE);
+}
+
+/****************************************************************************
+ * Name: up_ack_irq
+ *
+ * Description:
+ * Acknowledge the IRQ
+ *
+ ****************************************************************************/
+
+void up_ack_irq(int irq)
+{
+}
+
+/****************************************************************************
+ * Name: up_irq_save
+ *
+ * Description:
+ * Return the current interrupt state and disable interrupts
+ *
+ ****************************************************************************/
+
+irqstate_t up_irq_save(void)
+{
+ uint32_t oldstat;
+
+ /* Read mstatus & clear machine interrupt enable (MIE) in mstatus */
+
+ asm volatile ("csrrc %0, mstatus, %1": "=r" (oldstat) : "r"(MSTATUS_MIE));
+ return oldstat;
+}
+
+/****************************************************************************
+ * Name: up_irq_restore
+ *
+ * Description:
+ * Restore previous IRQ mask state
+ *
+ ****************************************************************************/
+
+void up_irq_restore(irqstate_t flags)
+{
+ /* Write flags to mstatus */
+
+ asm volatile("csrw mstatus, %0" : /* no output */ : "r" (flags));
+}
+
+/****************************************************************************
+ * Name: up_irq_enable
+ *
+ * Description:
+ * Return the current interrupt state and enable interrupts
+ *
+ ****************************************************************************/
+
+irqstate_t up_irq_enable(void)
+{
+ uint32_t oldstat;
+
+#if 1
+ /* Enable MEIE (machine external interrupt enable) */
+
+ /* TODO: should move to up_enable_irq() */
+
+ asm volatile ("csrrs %0, mie, %1": "=r" (oldstat) : "r"(MIE_MEIE));
+#endif
+
+ /* Read mstatus & set machine interrupt enable (MIE) in mstatus */
+
+ asm volatile ("csrrs %0, mstatus, %1": "=r" (oldstat) : "r"(MSTATUS_MIE));
+ return oldstat;
+}
diff --git a/arch/risc-v/src/litex/litex_irq_dispatch.c
b/arch/risc-v/src/litex/litex_irq_dispatch.c
new file mode 100644
index 0000000..9381076
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_irq_dispatch.c
@@ -0,0 +1,126 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_irq_dispatch.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <assert.h>
+
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+#include "up_arch.h"
+#include "up_internal.h"
+
+#include "litex.h"
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+volatile uint32_t * g_current_regs;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * litex_dispatch_irq
+ ****************************************************************************/
+
+void *litex_dispatch_irq(uint32_t vector, uint32_t *regs)
+{
+ uint32_t irq = (vector >> 27) | (vector & 0xf);
+ uint32_t *mepc = regs;
+ int i;
+
+ /* Firstly, check if the irq is machine external interrupt */
+
+ if (LITEX_IRQ_MEXT == irq)
+ {
+ /* litex vexriscv dont follow riscv plic standard */
+
+ unsigned int pending;
+ unsigned int mask;
+ asm volatile ("csrr %0, %1" : "=r"(pending) : "i"(LITEX_MPENDING_CSR));
+ asm volatile ("csrr %0, %1" : "=r"(mask) : "i"(LITEX_MMASK_CSR));
+
+ uint32_t val = (pending & mask);
+ for (i = 0; i < 32; i++)
+ {
+ if (val & (1 << i))
+ {
+ val = i;
+ val++;
+ break;
+ }
+ }
+
+ /* Add the value to nuttx irq which is offset to the mext */
+
+ irq += val;
+ }
+
+ /* NOTE: In case of ecall, we need to adjust mepc in the context */
+
+ if (LITEX_IRQ_ECALLM == irq)
+ {
+ *mepc += 4;
+ }
+
+ /* Acknowledge the interrupt */
+
+ up_ack_irq(irq);
+
+#ifdef CONFIG_SUPPRESS_INTERRUPTS
+ PANIC();
+#else
+ /* Current regs non-zero indicates that we are processing an interrupt;
+ * g_current_regs is also used to manage interrupt level context switches.
+ *
+ * Nested interrupts are not supported
+ */
+
+ DEBUGASSERT(g_current_regs == NULL);
+ g_current_regs = regs;
+
+ /* Deliver the IRQ */
+
+ irq_dispatch(irq, regs);
+
+#endif
+
+ /* If a context switch occurred while processing the interrupt then
+ * g_current_regs may have change value. If we return any value different
+ * from the input regs, then the lower level will know that a context
+ * switch occurred during interrupt processing.
+ */
+
+ regs = (uint32_t *)g_current_regs;
+ g_current_regs = NULL;
+
+ return regs;
+}
diff --git a/arch/risc-v/src/litex/litex_lowputc.c
b/arch/risc-v/src/litex/litex_lowputc.c
new file mode 100644
index 0000000..20054ee
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_lowputc.c
@@ -0,0 +1,124 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_lowputc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+
+#include <arch/board/board.h>
+
+#include "up_internal.h"
+#include "up_arch.h"
+
+#include "litex_config.h"
+#include "hardware/litex_memorymap.h"
+#include "hardware/litex_uart.h"
+#include "litex_clockconfig.h"
+#include "litex.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Select UART parameters for the selected console */
+
+#ifdef HAVE_SERIAL_CONSOLE
+# if defined(CONFIG_UART0_SERIAL_CONSOLE)
+# define LITEX_CONSOLE_BASE LITEX_UART0_BASE
+# define LITEX_CONSOLE_BAUD CONFIG_UART0_BAUD
+# define LITEX_CONSOLE_BITS CONFIG_UART0_BITS
+# define LITEX_CONSOLE_PARITY CONFIG_UART0_PARITY
+# define LITEX_CONSOLE_2STOP CONFIG_UART0_2STOP
+# define LITEX_CONSOLE_TX GPIO_UART0_TX
+# define LITEX_CONSOLE_RX GPIO_UART0_RX
+# define HAVE_UART
+# elif defined(CONFIG_UART1_SERIAL_CONSOLE)
+# define LITEX_CONSOLE_BASE LITEX_UART1_BASE
+# define LITEX_CONSOLE_BAUD CONFIG_UART1_BAUD
+# define LITEX_CONSOLE_BITS CONFIG_UART1_BITS
+# define LITEX_CONSOLE_PARITY CONFIG_UART1_PARITY
+# define LITEX_CONSOLE_2STOP CONFIG_UART1_2STOP
+# define LITEX_CONSOLE_TX GPIO_UART1_TX
+# define LITEX_CONSOLE_RX GPIO_UART1_RX
+# define HAVE_UART
+# endif
+#endif /* HAVE_CONSOLE */
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_lowputc
+ *
+ * Description:
+ * Output one byte on the serial console
+ *
+ ****************************************************************************/
+
+void up_lowputc(char ch)
+{
+#ifdef HAVE_SERIAL_CONSOLE
+ /* Wait until the TX data register is empty */
+
+ while (getreg8(LITEX_CONSOLE_BASE + UART_TXFULL_OFFSET))
+ ;
+
+ /* Then send the character */
+
+ putreg8(ch, LITEX_CONSOLE_BASE + UART_RXTX_OFFSET);
+ putreg8(UART_EV_TX, LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+
+#endif /* HAVE_CONSOLE */
+}
+
+/****************************************************************************
+ * Name: litex_lowsetup
+ *
+ * Description:
+ * This performs basic initialization of the UART used for the serial
+ * console. Its purpose is to get the console output available as soon
+ * as possible.
+ *
+ ****************************************************************************/
+
+void litex_lowsetup(void)
+{
+#if defined(HAVE_UART)
+
+ /* Enable and configure the selected console device */
+
+#if defined(HAVE_SERIAL_CONSOLE) && !defined(CONFIG_SUPPRESS_UART_CONFIG)
+
+ /* defualt baudrate set by fpga fabric is 1e6 */
+
+ /* Enable TX */
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ putreg8(UART_EV_TX, LITEX_CONSOLE_BASE + UART_EV_ENABLE_OFFSET);
+
+#endif /* HAVE_SERIAL_CONSOLE && !CONFIG_SUPPRESS_UART_CONFIG */
+#endif /* HAVE_UART */
+}
diff --git a/arch/risc-v/src/litex/litex_lowputc.h
b/arch/risc-v/src/litex/litex_lowputc.h
new file mode 100644
index 0000000..105c814
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_lowputc.h
@@ -0,0 +1,59 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_lowputc.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_LITEX_LITEX_LOWPUTC_H
+#define __ARCH_RISCV_SRC_LITEX_LITEX_LOWPUTC_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "chip.h"
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: litex_lowsetup
+ ****************************************************************************/
+
+EXTERN void litex_lowsetup(void);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_RISCV_SRC_LITEX_LITEX_LOWPUTC_H */
diff --git a/arch/risc-v/src/litex/litex_memorymap.h
b/arch/risc-v/src/litex/litex_memorymap.h
new file mode 100644
index 0000000..506c327
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_memorymap.h
@@ -0,0 +1,48 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_memorymap.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef _ARCH_RISCV_SRC_LITEX_LITEX_MEMORYMAP_H
+#define _ARCH_RISCV_SRC_LITEX_LITEX_MEMORYMAP_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include "hardware/litex_memorymap.h"
+#include "hardware/litex_uart.h"
+#include "hardware/litex_clint.h"
+#include "hardware/litex_plic.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Idle thread stack starts from _ebss */
+
+#ifndef __ASSEMBLY__
+#define LITEX_IDLESTACK_BASE (uint32_t)&_ebss
+#else
+#define LITEX_IDLESTACK_BASE _ebss
+#endif
+
+#define LITEX_IDLESTACK_SIZE (CONFIG_IDLETHREAD_STACKSIZE & ~3)
+#define LITEX_IDLESTACK_TOP (LITEX_IDLESTACK_BASE + LITEX_IDLESTACK_SIZE)
+
+#endif /* _ARCH_RISCV_SRC_LITEX_LITEX_MEMORYMAP_H */
diff --git a/arch/risc-v/src/litex/litex_serial.c
b/arch/risc-v/src/litex/litex_serial.c
new file mode 100644
index 0000000..02b5235
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_serial.c
@@ -0,0 +1,764 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_serial.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <nuttx/serial/serial.h>
+
+#include <arch/board/board.h>
+
+#include "up_arch.h"
+#include "up_internal.h"
+
+#include "litex_config.h"
+#include "chip.h"
+#include "litex.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Select UART parameters for the selected console */
+
+#ifdef HAVE_SERIAL_CONSOLE
+# if defined(CONFIG_UART0_SERIAL_CONSOLE)
+# define LITEX_CONSOLE_BASE LITEX_UART0_BASE
+# define LITEX_CONSOLE_BAUD CONFIG_UART0_BAUD
+# define LITEX_CONSOLE_BITS CONFIG_UART0_BITS
+# define LITEX_CONSOLE_PARITY CONFIG_UART0_PARITY
+# define LITEX_CONSOLE_2STOP CONFIG_UART0_2STOP
+# define LITEX_CONSOLE_TX GPIO_UART0_TX
+# define LITEX_CONSOLE_RX GPIO_UART0_RX
+# define HAVE_UART
+# elif defined(CONFIG_UART1_SERIAL_CONSOLE)
+# define LITEX_CONSOLE_BASE LITEX_UART1_BASE
+# define LITEX_CONSOLE_BAUD CONFIG_UART1_BAUD
+# define LITEX_CONSOLE_BITS CONFIG_UART1_BITS
+# define LITEX_CONSOLE_PARITY CONFIG_UART1_PARITY
+# define LITEX_CONSOLE_2STOP CONFIG_UART1_2STOP
+# define LITEX_CONSOLE_TX GPIO_UART1_TX
+# define LITEX_CONSOLE_RX GPIO_UART1_RX
+# define HAVE_UART
+# endif
+#endif /* HAVE_CONSOLE */
+
+/* If we are not using the serial driver for the console, then we still must
+ * provide some minimal implementation of up_putc.
+ */
+
+#ifdef USE_SERIALDRIVER
+
+/* Which UART with be tty0/console and which tty1? The console will always
+ * be ttyS0. If there is no console then will use the lowest numbered UART.
+ */
+
+#ifdef HAVE_SERIAL_CONSOLE
+# if defined(CONFIG_UART0_SERIAL_CONSOLE)
+# define CONSOLE_DEV g_uart0port /* UART0 is console */
+# define TTYS0_DEV g_uart0port /* UART0 is ttyS0 */
+# undef TTYS1_DEV /* No ttyS1 */
+# define SERIAL_CONSOLE 1
+# else
+# error "I'm confused... Do we have a serial console or not?"
+# endif
+#else
+# undef CONSOLE_DEV /* No console */
+# undef CONFIG_UART0_SERIAL_CONSOLE
+# if defined(CONFIG_LITEX_UART0)
+# define TTYS0_DEV g_uart0port /* UART0 is ttyS0 */
+# undef TTYS1_DEV /* No ttyS1 */
+# define SERIAL_CONSOLE 1
+# else
+# undef TTYS0_DEV
+# undef TTYS1_DEV
+# endif
+#endif
+
+/* Common initialization logic will not not know that the all of the UARTs
+ * have been disabled. So, as a result, we may still have to provide
+ * stub implementations of up_earlyserialinit(), up_serialinit(), and
+ * up_putc().
+ */
+
+#ifdef HAVE_UART_DEVICE
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct up_dev_s
+{
+ uintptr_t uartbase; /* Base address of UART registers */
+ uint32_t baud; /* Configured baud */
+ uint8_t irq; /* IRQ associated with this UART */
+ uint8_t im; /* Interrupt mask state */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* Low-level helpers */
+
+static uint32_t up_serialin(struct up_dev_s *priv, int offset);
+static void up_serialout(struct up_dev_s *priv, int offset, uint32_t value);
+static void up_restoreuartint(struct up_dev_s *priv, uint8_t im);
+static void up_disableuartint(struct up_dev_s *priv, uint8_t *im);
+
+/* Serial driver methods */
+
+static int up_setup(struct uart_dev_s *dev);
+static void up_shutdown(struct uart_dev_s *dev);
+static int up_attach(struct uart_dev_s *dev);
+static void up_detach(struct uart_dev_s *dev);
+static int up_interrupt(int irq, void *context, FAR void *arg);
+static int up_ioctl(struct file *filep, int cmd, unsigned long arg);
+static int up_receive(struct uart_dev_s *dev, uint32_t *status);
+static void up_rxint(struct uart_dev_s *dev, bool enable);
+static bool up_rxavailable(struct uart_dev_s *dev);
+static void up_send(struct uart_dev_s *dev, int ch);
+static void up_txint(struct uart_dev_s *dev, bool enable);
+static bool up_txready(struct uart_dev_s *dev);
+static bool up_txempty(struct uart_dev_s *dev);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct uart_ops_s g_uart_ops =
+{
+ .setup = up_setup,
+ .shutdown = up_shutdown,
+ .attach = up_attach,
+ .detach = up_detach,
+ .ioctl = up_ioctl,
+ .receive = up_receive,
+ .rxint = up_rxint,
+ .rxavailable = up_rxavailable,
+#ifdef CONFIG_SERIAL_IFLOWCONTROL
+ .rxflowcontrol = NULL,
+#endif
+ .send = up_send,
+ .txint = up_txint,
+ .txready = up_txready,
+ .txempty = up_txempty,
+};
+
+/* I/O buffers */
+
+#ifdef CONFIG_LITEX_UART0
+static char g_uart0rxbuffer[CONFIG_UART0_RXBUFSIZE];
+static char g_uart0txbuffer[CONFIG_UART0_TXBUFSIZE];
+#endif
+
+#ifdef CONFIG_LITEX_UART0
+static struct up_dev_s g_uart0priv =
+{
+ .uartbase = LITEX_UART0_BASE,
+ .baud = CONFIG_UART0_BAUD,
+ .irq = LITEX_IRQ_UART0,
+};
+
+static uart_dev_t g_uart0port =
+{
+#if SERIAL_CONSOLE == 1
+ .isconsole = 1,
+#endif
+ .recv =
+ {
+ .size = CONFIG_UART0_RXBUFSIZE,
+ .buffer = g_uart0rxbuffer,
+ },
+ .xmit =
+ {
+ .size = CONFIG_UART0_TXBUFSIZE,
+ .buffer = g_uart0txbuffer,
+ },
+ .ops = &g_uart_ops,
+ .priv = &g_uart0priv,
+};
+#endif
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_serialin
+ ****************************************************************************/
+
+static uint32_t up_serialin(struct up_dev_s *priv, int offset)
+{
+ return getreg32(priv->uartbase + offset);
+}
+
+/****************************************************************************
+ * Name: up_serialout
+ ****************************************************************************/
+
+static void up_serialout(struct up_dev_s *priv, int offset, uint32_t value)
+{
+ putreg32(value, priv->uartbase + offset);
+}
+
+/****************************************************************************
+ * Name: up_restoreuartint
+ ****************************************************************************/
+
+static void up_restoreuartint(struct up_dev_s *priv, uint8_t im)
+{
+ irqstate_t flags = enter_critical_section();
+
+ priv->im = im;
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ up_serialout(priv, UART_EV_ENABLE_OFFSET, im);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: up_disableuartint
+ ****************************************************************************/
+
+static void up_disableuartint(struct up_dev_s *priv, uint8_t *im)
+{
+ irqstate_t flags = enter_critical_section();
+
+ /* Return the current interrupt mask value */
+
+ if (im)
+ {
+ *im = priv->im;
+ }
+
+ /* Disable all interrupts */
+
+ priv->im = 0;
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ up_serialout(priv, UART_EV_ENABLE_OFFSET, 0);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: up_setup
+ *
+ * Description:
+ * Configure the UART baud, bits, parity, etc. This method is called the
+ * first time that the serial port is opened.
+ *
+ ****************************************************************************/
+
+static int up_setup(struct uart_dev_s *dev)
+{
+#if 0 /* TODO: Setup divisor */
+#endif
+
+ return OK;
+}
+
+/****************************************************************************
+ * Name: up_shutdown
+ *
+ * Description:
+ * Disable the UART. This method is called when the serial
+ * port is closed
+ *
+ ****************************************************************************/
+
+static void up_shutdown(struct uart_dev_s *dev)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+
+ /* Disable interrupts */
+
+ up_disableuartint(priv, NULL);
+}
+
+/****************************************************************************
+ * Name: up_attach
+ *
+ * Description:
+ * Configure the UART to operation in interrupt driven mode. This method
+ * is called when the serial port is opened. Normally, this is just after
+ * the the setup() method is called, however, the serial console may
+ * operate in a non-interrupt driven mode during the boot phase.
+ *
+ * RX and TX interrupts are not enabled by the attach method (unless the
+ * hardware supports multiple levels of interrupt enabling). The RX and TX
+ * interrupts are not enabled until the txint() and rxint() are called.
+ *
+ ****************************************************************************/
+
+static int up_attach(struct uart_dev_s *dev)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+ int ret;
+
+ /* Initialize interrupt generation on the peripheral */
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ up_serialout(priv, UART_EV_ENABLE_OFFSET, UART_EV_TX | UART_EV_RX);
+
+ ret = irq_attach(priv->irq, up_interrupt, dev);
+
+ if (ret == OK)
+ {
+ /* Enable the interrupt (RX and TX interrupts are still disabled
+ * in the UART
+ */
+
+ up_enable_irq(priv->irq);
+ }
+
+ return ret;
+}
+
+/****************************************************************************
+ * Name: up_detach
+ *
+ * Description:
+ * Detach UART interrupts. This method is called when the serial port is
+ * closed normally just before the shutdown method is called. The
+ * exception is the serial console which is never shutdown.
+ *
+ ****************************************************************************/
+
+static void up_detach(struct uart_dev_s *dev)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+
+ /* Disable interrupts */
+
+ up_disable_irq(priv->irq);
+
+ /* Detach from the interrupt */
+
+ irq_detach(priv->irq);
+}
+
+/****************************************************************************
+ * Name: up_interrupt
+ *
+ * Description:
+ * This is the UART interrupt handler. It will be invoked when an
+ * interrupt received on the 'irq' It should call uart_transmitchars or
+ * uart_receivechar to perform the appropriate data transfers. The
+ * interrupt handling logic must be able to map the 'irq' number into the
+ * appropriate uart_dev_s structure in order to call these functions.
+ *
+ ****************************************************************************/
+
+static int up_interrupt(int irq, void *context, FAR void *arg)
+{
+ struct uart_dev_s *dev = (struct uart_dev_s *)arg;
+ struct up_dev_s *priv;
+ uint32_t status;
+ int passes;
+
+ DEBUGASSERT(dev != NULL && dev->priv != NULL);
+ priv = (struct up_dev_s *)dev->priv;
+
+ /* Loop until there are no characters to be transferred or,
+ * until we have been looping for a long time.
+ */
+
+ for (passes = 0; passes < 256; passes++)
+ {
+ /* Retrieve interrupt pending status */
+
+ status = up_serialin(priv, UART_EV_PENDING_OFFSET);
+
+ if (status == 0)
+ {
+ break;
+ }
+
+ if (status & UART_EV_RX)
+ {
+ /* Process incoming bytes */
+
+ uart_recvchars(dev);
+ }
+
+ if (status & UART_EV_TX)
+ {
+ /* Process outgoing bytes */
+
+ putreg8(UART_EV_TX, LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ uart_xmitchars(dev);
+ }
+ }
+
+ return OK;
+}
+
+/****************************************************************************
+ * Name: up_ioctl
+ *
+ * Description:
+ * All ioctl calls will be routed through this method
+ *
+ ****************************************************************************/
+
+static int up_ioctl(struct file *filep, int cmd, unsigned long arg)
+{
+ return -ENOTTY;
+}
+
+/****************************************************************************
+ * Name: up_receive
+ *
+ * Description:
+ * Called (usually) from the interrupt level to receive one
+ * character from the UART. Error bits associated with the
+ * receipt are provided in the return 'status'.
+ *
+ ****************************************************************************/
+
+static int up_receive(struct uart_dev_s *dev, uint32_t *status)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+ int rxdata;
+
+ /* Return status information */
+
+ if (status)
+ {
+ *status = 0; /* We are not yet tracking serial errors */
+ }
+
+ rxdata = (int)(up_serialin(priv, UART_RXTX_OFFSET));
+ putreg8(UART_EV_RX, LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+
+ return rxdata;
+}
+
+/****************************************************************************
+ * Name: up_rxint
+ *
+ * Description:
+ * Call to enable or disable RX interrupts
+ *
+ ****************************************************************************/
+
+static void up_rxint(struct uart_dev_s *dev, bool enable)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+ irqstate_t flags = enter_critical_section();
+
+ if (enable)
+ {
+#ifndef CONFIG_SUPPRESS_SERIAL_INTS
+ priv->im |= UART_EV_RX;
+#endif
+ }
+ else
+ {
+ priv->im &= ~UART_EV_RX;
+ }
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ up_serialout(priv, UART_EV_ENABLE_OFFSET, priv->im);
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: up_rxavailable
+ *
+ * Description:
+ * Return true if the receive register is not empty
+ *
+ ****************************************************************************/
+
+static bool up_rxavailable(struct uart_dev_s *dev)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+
+ /* Return true is data is available in the receive data buffer */
+
+ uint32_t rxempty = up_serialin(priv, UART_RXEMPTY_OFFSET);
+
+ return rxempty == 0;
+}
+
+/****************************************************************************
+ * Name: up_send
+ *
+ * Description:
+ * This method will send one byte on the UART.
+ *
+ ****************************************************************************/
+
+static void up_send(struct uart_dev_s *dev, int ch)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+ up_serialout(priv, UART_RXTX_OFFSET, (uint32_t)ch);
+}
+
+/****************************************************************************
+ * Name: up_txint
+ *
+ * Description:
+ * Call to enable or disable TX interrupts
+ *
+ ****************************************************************************/
+
+static void up_txint(struct uart_dev_s *dev, bool enable)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+ irqstate_t flags;
+
+ flags = enter_critical_section();
+ if (enable)
+ {
+ /* Enable the TX interrupt */
+
+#ifndef CONFIG_SUPPRESS_SERIAL_INTS
+ priv->im |= UART_EV_TX;
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ up_serialout(priv, UART_EV_ENABLE_OFFSET, priv->im);
+
+ /* Fake a TX interrupt here by just calling uart_xmitchars() with
+ * interrupts disabled (note this may recurse).
+ */
+
+ uart_xmitchars(dev);
+#endif
+ }
+ else
+ {
+ /* Disable the TX interrupt */
+
+ priv->im &= ~UART_EV_TX;
+
+ putreg8(getreg8(LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET), \
+ LITEX_CONSOLE_BASE + UART_EV_PENDING_OFFSET);
+ up_serialout(priv, UART_EV_ENABLE_OFFSET, priv->im);
+ }
+
+ leave_critical_section(flags);
+}
+
+/****************************************************************************
+ * Name: up_txready
+ *
+ * Description:
+ * Return true if the tranmsit data register is not full
+ *
+ ****************************************************************************/
+
+static bool up_txready(struct uart_dev_s *dev)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+
+ /* Return TRUE if the TX FIFO is not full */
+
+ return (up_serialin(priv, UART_TXFULL_OFFSET)) == 0;
+}
+
+/****************************************************************************
+ * Name: up_txempty
+ *
+ * Description:
+ * Return true if the tranmsit data register is empty
+ *
+ ****************************************************************************/
+
+static bool up_txempty(struct uart_dev_s *dev)
+{
+ struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
+
+ /* Return TRUE if the TX is pending */
+
+ return (up_serialin(priv, UART_EV_PENDING_OFFSET) & UART_EV_TX) == 1;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+#ifdef USE_EARLYSERIALINIT
+
+/****************************************************************************
+ * Name: up_earlyserialinit
+ *
+ * Description:
+ * Performs the low level UART initialization early in debug so that the
+ * serial console will be available during bootup. This must be called
+ * before up_serialinit. NOTE: This function depends on GPIO pin
+ * configuration performed in up_consoleinit() and main clock iniialization
+ * performed in up_clkinitialize().
+ *
+ ****************************************************************************/
+
+void up_earlyserialinit(void)
+{
+ /* Disable interrupts from all UARTS. The console is enabled in
+ * litex_consoleinit().
+ */
+
+ up_disableuartint(TTYS0_DEV.priv, NULL);
+#ifdef TTYS1_DEV
+ up_disableuartint(TTYS1_DEV.priv, NULL);
+#endif
+
+ /* Configuration whichever one is the console */
+
+#ifdef HAVE_SERIAL_CONSOLE
+ CONSOLE_DEV.isconsole = true;
+ up_setup(&CONSOLE_DEV);
+#endif
+}
+#endif
+
+/****************************************************************************
+ * Name: up_serialinit
+ *
+ * Description:
+ * Register serial console and serial ports. This assumes
+ * that up_earlyserialinit was called previously.
+ *
+ ****************************************************************************/
+
+void up_serialinit(void)
+{
+ /* Register the console */
+
+#ifdef HAVE_SERIAL_CONSOLE
+ uart_register("/dev/console", &CONSOLE_DEV);
+#endif
+
+ /* Register all UARTs */
+
+ uart_register("/dev/ttyS0", &TTYS0_DEV);
+#ifdef TTYS1_DEV
+ uart_register("/dev/ttyS1", &TTYS1_DEV);
+#endif
+}
+
+/****************************************************************************
+ * Name: up_putc
+ *
+ * Description:
+ * Provide priority, low-level access to support OS debug writes
+ *
+ ****************************************************************************/
+
+int up_putc(int ch)
+{
+#ifdef HAVE_SERIAL_CONSOLE
+ struct up_dev_s *priv = (struct up_dev_s *)CONSOLE_DEV.priv;
+ uint8_t imr;
+
+ up_disableuartint(priv, &imr);
+
+ /* Check for LF */
+
+ if (ch == '\n')
+ {
+ /* Add CR */
+
+ up_lowputc('\r');
+ }
+
+ up_lowputc(ch);
+ up_restoreuartint(priv, imr);
+#endif
+ return ch;
+}
+
+/****************************************************************************
+ * Name: up_earlyserialinit, up_serialinit, and up_putc
+ *
+ * Description:
+ * stubs that may be needed. These stubs would be used if all UARTs are
+ * disabled. In that case, the logic in common/up_initialize() is not
+ * smart enough to know that there are not UARTs and will still expect
+ * these interfaces to be provided.
+ *
+ ****************************************************************************/
+
+#else /* HAVE_UART_DEVICE */
+void up_earlyserialinit(void)
+{
+}
+
+void up_serialinit(void)
+{
+}
+
+int up_putc(int ch)
+{
+ return ch;
+}
+
+#endif /* HAVE_UART_DEVICE */
+#else /* USE_SERIALDRIVER */
+
+/****************************************************************************
+ * Name: up_putc
+ *
+ * Description:
+ * Provide priority, low-level access to support OS debug writes
+ *
+ ****************************************************************************/
+
+int up_putc(int ch)
+{
+#ifdef HAVE_SERIAL_CONSOLE
+ /* Check for LF */
+
+ if (ch == '\n')
+ {
+ /* Add CR */
+
+ up_lowputc('\r');
+ }
+
+ up_lowputc(ch);
+#endif
+ return ch;
+}
+
+#endif /* USE_SERIALDRIVER */
diff --git a/arch/risc-v/src/litex/litex_start.c
b/arch/risc-v/src/litex/litex_start.c
new file mode 100644
index 0000000..c3022b4
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_start.c
@@ -0,0 +1,125 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_init.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <stdint.h>
+
+#include <nuttx/config.h>
+
+#include <arch/board/board.h>
+
+#include "litex_clockconfig.h"
+#include "litex.h"
+#include "chip.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_DEBUG_FEATURES
+# define showprogress(c) up_lowputc(c)
+#else
+# define showprogress(c)
+#endif
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* g_idle_topstack: _sbss is the start of the BSS region as defined by the
+ * linker script. _ebss lies at the end of the BSS region. The idle task
+ * stack starts at the end of BSS and is of size CONFIG_IDLETHREAD_STACKSIZE.
+ * The IDLE thread is the thread that the system boots on and, eventually,
+ * becomes the IDLE, do nothing task that runs only when there is nothing
+ * else to run. The heap continues from there until the end of memory.
+ * g_idle_topstack is a read-only variable the provides this computed
+ * address.
+ */
+
+uint32_t g_idle_topstack = LITEX_IDLESTACK_TOP;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: litex_start
+ ****************************************************************************/
+
+void __litex_start(void)
+{
+ const uint32_t *src;
+ uint32_t *dest;
+
+ /* Clear .bss. We'll do this inline (vs. calling memset) just to be
+ * certain that there are no issues with the state of global variables.
+ */
+
+ for (dest = &_sbss; dest < &_ebss; )
+ {
+ *dest++ = 0;
+ }
+
+ /* Move the initialized data section from his temporary holding spot in
+ * FLASH into the correct place in SRAM. The correct place in SRAM is
+ * give by _sdata and _edata. The temporary location is in FLASH at the
+ * end of all of the other read-only data (.text, .rodata) at _eronly.
+ */
+
+ /* for vexriscv the full image is loaded in ddr ram */
+
+ for (src = &_eronly, dest = &_sdata; dest < &_edata; )
+ {
+ *dest++ = *src++;
+ }
+
+ /* Setup PLL */
+
+ litex_clockconfig();
+
+ /* Configure the UART so we can get debug output */
+
+ litex_lowsetup();
+
+ showprogress('A');
+
+#ifdef USE_EARLYSERIALINIT
+ up_earlyserialinit();
+#endif
+
+ showprogress('B');
+
+ /* Do board initialization */
+
+ litex_boardinitialize();
+
+ showprogress('C');
+
+ /* Call nx_start() */
+
+ nx_start();
+
+ /* Shouldn't get here */
+
+ for (; ; );
+}
diff --git a/arch/risc-v/src/litex/litex_timerisr.c
b/arch/risc-v/src/litex/litex_timerisr.c
new file mode 100644
index 0000000..48449a4
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_timerisr.c
@@ -0,0 +1,202 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_timerisr.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <time.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/clock.h>
+#include <arch/board/board.h>
+
+#include "up_arch.h"
+
+#include "litex.h"
+#include "litex_clockconfig.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define TICK_COUNT (litex_get_hfclk() / TICK_PER_SEC)
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static bool _b_tick_started = false;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/* litex mmio registers are a bit odd, by default they are byte-wide
+ * registers that are on 32-bit word boundaries. So a "32-bit" registers
+ * is actually broken into four bytes spanning a total address space of
+ * 16 bytes.
+ */
+
+static inline uint64_t litex_clint_time_read(void)
+{
+ uint64_t r = getreg8(LITEX_CLINT_MTIME);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x04);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x08);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x0c);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x10);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x14);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x18);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIME + 0x1c);
+ return r;
+}
+
+static inline uint64_t litex_clint_time_cmp_read(void)
+{
+ uint64_t r = getreg8(LITEX_CLINT_MTIMECMP);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x04);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x08);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x0c);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x10);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x14);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x18);
+ r <<= 8;
+ r |= getreg8(LITEX_CLINT_MTIMECMP + 0x1c);
+ return r;
+}
+
+static inline void litex_clint_time_cmp_write(uint64_t v)
+{
+ putreg8(v >> 56, LITEX_CLINT_MTIMECMP);
+ putreg8(v >> 48, LITEX_CLINT_MTIMECMP + 0x04);
+ putreg8(v >> 40, LITEX_CLINT_MTIMECMP + 0x08);
+ putreg8(v >> 32, LITEX_CLINT_MTIMECMP + 0x0c);
+ putreg8(v >> 24, LITEX_CLINT_MTIMECMP + 0x10);
+ putreg8(v >> 16, LITEX_CLINT_MTIMECMP + 0x14);
+ putreg8(v >> 8, LITEX_CLINT_MTIMECMP + 0x18);
+ putreg8(v, LITEX_CLINT_MTIMECMP + 0x1c);
+}
+
+/* helper function to set/clear csr */
+
+#define csr_clear(csr, val) \
+({ \
+ unsigned long __v = (unsigned long)(val); \
+ __asm__ __volatile__ ("csrc " #csr ", %0" \
+ : : "rK" (__v)); \
+})
+
+#define csr_set(csr, val) \
+({ \
+ unsigned long __v = (unsigned long)(val); \
+ __asm__ __volatile__ ("csrs " #csr ", %0" \
+ : : "rK" (__v)); \
+})
+
+/****************************************************************************
+ * Name: litex_reload_mtimecmp
+ ****************************************************************************/
+
+static void litex_reload_mtimecmp(void)
+{
+ irqstate_t flags = spin_lock_irqsave();
+
+ uint64_t current;
+ uint64_t next;
+
+ if (!_b_tick_started)
+ {
+ _b_tick_started = true;
+ putreg8(1, LITEX_CLINT_LATCH);
+ current = litex_clint_time_read();
+ }
+ else
+ {
+ current = litex_clint_time_cmp_read();
+ }
+
+ next = current + TICK_COUNT;
+
+ litex_clint_time_cmp_write(next);
+ putreg8(1, LITEX_CLINT_LATCH);
+ csr_set(mie, MIE_MTIE);
+ csr_clear(mip, MIP_MTIP);
+
+ spin_unlock_irqrestore(flags);
+}
+
+/****************************************************************************
+ * Name: litex_timerisr
+ ****************************************************************************/
+
+static int litex_timerisr(int irq, void *context, FAR void *arg)
+{
+ litex_reload_mtimecmp();
+
+ /* Process timer interrupt */
+
+ nxsched_process_timer();
+ return 0;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_timer_initialize
+ *
+ * Description:
+ * This function is called during start-up to initialize
+ * the timer interrupt.
+ *
+ ****************************************************************************/
+
+void up_timer_initialize(void)
+{
+ /* Attach timer interrupt handler */
+
+ irq_attach(LITEX_IRQ_MTIMER, litex_timerisr, NULL);
+
+ /* Reload CLINT mtimecmp */
+
+ litex_reload_mtimecmp();
+
+ /* And enable the timer interrupt */
+
+ up_enable_irq(LITEX_IRQ_MTIMER);
+}
diff --git a/arch/risc-v/src/litex/litex_vectors.S
b/arch/risc-v/src/litex/litex_vectors.S
new file mode 100644
index 0000000..da77137
--- /dev/null
+++ b/arch/risc-v/src/litex/litex_vectors.S
@@ -0,0 +1,42 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/litex_vectors.S
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/************************************************************************************
+ * Included Files
+
************************************************************************************/
+
+ .section .text.vec
+ .global __reset_vec
+ .global __trap_vec
+
+/****************************************************************************
+ * Name: __reset_vec
+ ****************************************************************************/
+
+__reset_vec:
+ jal __start
+
+/****************************************************************************
+ * Name: exception_common
+ ****************************************************************************/
+
+__trap_vec:
+ j exception_common
+ nop
diff --git a/arch/risc-v/src/litex/up_schedulesigaction.c
b/arch/risc-v/src/litex/up_schedulesigaction.c
new file mode 100644
index 0000000..1becce5
--- /dev/null
+++ b/arch/risc-v/src/litex/up_schedulesigaction.c
@@ -0,0 +1,192 @@
+/****************************************************************************
+ * arch/risc-v/src/litex/up_schedulesigaction.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <sched.h>
+#include <debug.h>
+
+#include <nuttx/irq.h>
+#include <nuttx/arch.h>
+#include <arch/litex/irq.h>
+
+#include "sched/sched.h"
+#include "up_internal.h"
+#include "up_arch.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_schedule_sigaction
+ *
+ * Description:
+ * This function is called by the OS when one or more
+ * signal handling actions have been queued for execution.
+ * The architecture specific code must configure things so
+ * that the 'igdeliver' callback is executed on the thread
+ * specified by 'tcb' as soon as possible.
+ *
+ * This function may be called from interrupt handling logic.
+ *
+ * This operation should not cause the task to be unblocked
+ * nor should it cause any immediate execution of sigdeliver.
+ * Typically, a few cases need to be considered:
+ *
+ * (1) This function may be called from an interrupt handler
+ * During interrupt processing, all xcptcontext structures
+ * should be valid for all tasks. That structure should
+ * be modified to invoke sigdeliver() either on return
+ * from (this) interrupt or on some subsequent context
+ * switch to the recipient task.
+ * (2) If not in an interrupt handler and the tcb is NOT
+ * the currently executing task, then again just modify
+ * the saved xcptcontext structure for the recipient
+ * task so it will invoke sigdeliver when that task is
+ * later resumed.
+ * (3) If not in an interrupt handler and the tcb IS the
+ * currently executing task -- just call the signal
+ * handler now.
+ *
+ ****************************************************************************/
+
+void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
+{
+ irqstate_t flags;
+ uint32_t int_ctx;
+
+ sinfo("tcb=0x%p sigdeliver=0x%p\n", tcb, sigdeliver);
+
+ /* Make sure that interrupts are disabled */
+
+ flags = enter_critical_section();
+
+ /* Refuse to handle nested signal actions */
+
+ if (!tcb->xcp.sigdeliver)
+ {
+ /* First, handle some special cases when the signal is
+ * being delivered to the currently executing task.
+ */
+
+ sinfo("rtcb=0x%p g_current_regs=0x%p\n",
+ this_task(), g_current_regs);
+
+ if (tcb == this_task())
+ {
+ /* CASE 1: We are not in an interrupt handler and
+ * a task is signalling itself for some reason.
+ */
+
+ if (!g_current_regs)
+ {
+ /* In this case just deliver the signal now. */
+
+ sigdeliver(tcb);
+ }
+
+ /* CASE 2: We are in an interrupt handler AND the
+ * interrupted task is the same as the one that
+ * must receive the signal, then we will have to modify
+ * the return state as well as the state in the TCB.
+ *
+ * Hmmm... there looks like a latent bug here: The following
+ * logic would fail in the strange case where we are in an
+ * interrupt handler, the thread is signalling itself, but
+ * a context switch to another task has occurred so that
+ * g_current_regs does not refer to the thread of this_task()!
+ */
+
+ else
+ {
+ /* Save the return EPC and STATUS registers. These will be
+ * restored by the signal trampoline after the signals have
+ * been delivered.
+ */
+
+ tcb->xcp.sigdeliver = sigdeliver;
+ tcb->xcp.saved_epc = g_current_regs[REG_EPC];
+ tcb->xcp.saved_int_ctx = g_current_regs[REG_INT_CTX];
+
+ /* Then set up to vector to the trampoline with interrupts
+ * disabled
+ */
+
+ g_current_regs[REG_EPC] = (uint32_t)up_sigdeliver;
+
+ int_ctx = g_current_regs[REG_INT_CTX];
+ int_ctx &= ~MSTATUS_MIE;
+
+ g_current_regs[REG_INT_CTX] = int_ctx;
+
+ /* And make sure that the saved context in the TCB
+ * is the same as the interrupt return context.
+ */
+
+ up_savestate(tcb->xcp.regs);
+
+ sinfo("PC/STATUS Saved: %08x/%08x New: %08x/%08x\n",
+ tcb->xcp.saved_epc, tcb->xcp.saved_int_ctx,
+ g_current_regs[REG_EPC], g_current_regs[REG_INT_CTX]);
+ }
+ }
+
+ /* Otherwise, we are (1) signaling a task is not running
+ * from an interrupt handler or (2) we are not in an
+ * interrupt handler and the running task is signalling
+ * some non-running task.
+ */
+
+ else
+ {
+ /* Save the return EPC and STATUS registers. These will be
+ * restored by the signal trampoline after the signals have
+ * been delivered.
+ */
+
+ tcb->xcp.sigdeliver = sigdeliver;
+ tcb->xcp.saved_epc = tcb->xcp.regs[REG_EPC];
+ tcb->xcp.saved_int_ctx = tcb->xcp.regs[REG_INT_CTX];
+
+ /* Then set up to vector to the trampoline with interrupts
+ * disabled
+ */
+
+ tcb->xcp.regs[REG_EPC] = (uint32_t)up_sigdeliver;
+
+ int_ctx = tcb->xcp.regs[REG_INT_CTX];
+ int_ctx &= ~MSTATUS_MIE;
+
+ tcb->xcp.regs[REG_INT_CTX] = int_ctx;
+
+ sinfo("PC/STATUS Saved: %08x/%08x New: %08x/%08x\n",
+ tcb->xcp.saved_epc, tcb->xcp.saved_int_ctx,
+ tcb->xcp.regs[REG_EPC], tcb->xcp.regs[REG_INT_CTX]);
+ }
+ }
+
+ leave_critical_section(flags);
+}
diff --git a/boards/Kconfig b/boards/Kconfig
index 8a33c2c..f241372 100644
--- a/boards/Kconfig
+++ b/boards/Kconfig
@@ -43,6 +43,13 @@ config ARCH_BOARD_ARDUINO_M0
This options selects the Arduino M0 board featuring the Atmel
ATSAMD21 MCU.
+config ARCH_BOARD_ARTY_A7
+ bool "DIGILENT ARTY_A7 board"
+ depends on ARCH_CHIP_LITEX
+ ---help---
+ This is the board configuration for the port of NuttX to the
Digilent ARTY A7
+ board. This board features the RISC-V litex vexriscv softcore
+
config ARCH_BOARD_AVR32DEV1
bool "Atmel AVR32DEV1 board"
depends on ARCH_CHIP_AT32UC3B0256
@@ -2058,6 +2065,7 @@ config ARCH_BOARD
default "arduino-mega2560" if ARCH_BOARD_ARDUINO_MEGA2560
default "arduino-due" if ARCH_BOARD_ARDUINO_DUE
default "arduino-m0" if ARCH_BOARD_ARDUINO_M0
+ default "arty_a7" if ARCH_BOARD_ARTY_A7
default "avr32dev1" if ARCH_BOARD_AVR32DEV1
default "axoloti" if ARCH_BOARD_AXOLOTI
default "bambino-200e" if ARCH_BOARD_BAMBINO_200E
@@ -2819,6 +2827,9 @@ endif
if ARCH_BOARD_US7032EVB1
source "boards/renesas/sh1/us7032evb1/Kconfig"
endif
+if ARCH_BOARD_ARTY_A7
+source "boards/risc-v/litex/arty_a7/Kconfig"
+endif
if ARCH_BOARD_GAPUINO
source "boards/risc-v/gap8/gapuino/Kconfig"
endif
diff --git a/boards/risc-v/litex/arty_a7/Kconfig
b/boards/risc-v/litex/arty_a7/Kconfig
new file mode 100644
index 0000000..cedc8e4
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/Kconfig
@@ -0,0 +1,8 @@
+#
+# For a description of the syntax of this configuration file,
+# see misc/tools/kconfig-language.txt.
+#
+
+if ARCH_BOARD_ARTY_A7
+
+endif
diff --git a/boards/risc-v/litex/arty_a7/README.txt
b/boards/risc-v/litex/arty_a7/README.txt
new file mode 100644
index 0000000..e7bd857
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/README.txt
@@ -0,0 +1,28 @@
+1. Download and install toolchain
+
+ $ curl
https://static.dev.sifive.com/dev-tools/riscv64-unknown-elf-gcc-8.3.0-2019.08.0-x86_64-linux-ubuntu14.tar.gz
+
+2. Follow instruction on https://github.com/enjoy-digital/litex to build the
vexriscv softcore fpga gateware
+ and flash to arty_a7 board
+
+3. Configure and build NuttX
+
+ $ mkdir ./nuttx; cd ./nuttx
+ $ git clone https://bitbucket.org/nuttx/nuttx.git
+ $ git clone https://bitbucket.org/nuttx/apps.git
+ $ cd nuttx
+ $ make distclean
+ $ ./tools/configure.sh arty_a7:nsh
+ $ make V=1
+
+4. Setup tftp server on your laptop, copy nuttx.bin to your tftpboot directory
and change its name to boot.bin
+
+5. Setup the wire connection(uart and tftp) between your board and laptop
+
+6. Run $ minicom -b 1000000 /dev/ttyUSB1 (the default baudrate on litex
vexriscv is 1e6)
+ when you see the bios prompt "litex>", type "netboot" and enter soon comes
the nsh prompt
+
+7. TODO
+
+ Support GPIO/SPI/I2C/RTC/WDT/PWM
+ Support RISC-V User mode
diff --git a/boards/risc-v/litex/arty_a7/configs/nsh/defconfig
b/boards/risc-v/litex/arty_a7/configs/nsh/defconfig
new file mode 100644
index 0000000..09fd4f1
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/configs/nsh/defconfig
@@ -0,0 +1,74 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed
.config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that
includes your
+# modifications.
+#
+# CONFIG_NSH_DISABLEBG is not set
+# CONFIG_NSH_DISABLE_LOSMART is not set
+# CONFIG_NSH_DISABLE_UNAME is not set
+# CONFIG_STANDARD_SERIAL is not set
+CONFIG_ARCH="risc-v"
+CONFIG_ARCH_BOARD="arty_a7"
+CONFIG_ARCH_BOARD_ARTY_A7=y
+CONFIG_ARCH_CHIP="litex"
+CONFIG_ARCH_CHIP_LITEX=y
+CONFIG_ARCH_INTERRUPTSTACK=8192
+CONFIG_ARCH_RISCV=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BINFMT_DISABLE=y
+CONFIG_BOARD_LOOPSPERMSEC=10000
+CONFIG_BUILTIN=y
+CONFIG_DEBUG_FULLOPT=y
+CONFIG_DEBUG_SYMBOLS=y
+CONFIG_DEFAULT_SMALL=y
+CONFIG_DEV_ZERO=y
+CONFIG_DISABLE_MQUEUE=y
+CONFIG_EXAMPLES_HELLO=y
+CONFIG_EXAMPLES_HELLO_STACKSIZE=8192
+CONFIG_FS_PROCFS=y
+CONFIG_FS_WRITABLE=y
+CONFIG_IDLETHREAD_STACKSIZE=8192
+CONFIG_INTELHEX_BINARY=y
+CONFIG_LIBC_PERROR_STDOUT=y
+CONFIG_LIBC_STRERROR=y
+CONFIG_MAX_TASKS=8
+CONFIG_MAX_WDOGPARMS=2
+CONFIG_NFILE_DESCRIPTORS=6
+CONFIG_NFILE_STREAMS=6
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_DISABLE_CD=y
+CONFIG_NSH_DISABLE_CP=y
+CONFIG_NSH_DISABLE_IFUPDOWN=y
+CONFIG_NSH_DISABLE_MKDIR=y
+CONFIG_NSH_DISABLE_RM=y
+CONFIG_NSH_DISABLE_RMDIR=y
+CONFIG_NSH_DISABLE_UMOUNT=y
+CONFIG_NSH_FILEIOSIZE=64
+CONFIG_NSH_STRERROR=y
+CONFIG_PREALLOC_TIMERS=0
+CONFIG_PREALLOC_WDOGS=4
+CONFIG_PTHREAD_STACK_DEFAULT=8192
+CONFIG_RAM_SIZE=134217728
+CONFIG_RAM_START=0xc0800000
+CONFIG_RAW_BINARY=y
+CONFIG_RR_INTERVAL=200
+CONFIG_RV32IM_CUSTOM_IRQ_SUPPORT=y
+CONFIG_SCHED_WAITPID=y
+CONFIG_STACK_COLORATION=y
+CONFIG_START_DAY=20
+CONFIG_START_MONTH=3
+CONFIG_START_YEAR=2020
+CONFIG_STDIO_DISABLE_BUFFERING=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_TASK_NAME_SIZE=12
+CONFIG_TASK_SPAWN_DEFAULT_STACKSIZE=8192
+CONFIG_TESTING_GETPRIME=y
+CONFIG_UART0_RXBUFSIZE=128
+CONFIG_UART0_SERIAL_CONSOLE=y
+CONFIG_UART0_TXBUFSIZE=128
+CONFIG_USERMAIN_STACKSIZE=8192
+CONFIG_USER_ENTRYPOINT="nsh_main"
+CONFIG_WDOG_INTRESERVE=0
diff --git a/boards/risc-v/litex/arty_a7/include/board.h
b/boards/risc-v/litex/arty_a7/include/board.h
new file mode 100644
index 0000000..f9b5e64
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/include/board.h
@@ -0,0 +1,68 @@
+/****************************************************************************
+ * boards/risc-v/litex/arty_a7/include/board.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __BOARDS_RISCV_LITEX_ARTY_A7_INCLUDE_BOARD_H
+#define __BOARDS_RISCV_LITEX_ARTY_A7_INCLUDE_BOARD_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: litex_boardinitialize
+ ****************************************************************************/
+
+void litex_boardinitialize(void);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+#endif /* __ASSEMBLY__ */
+#endif /* __BOARDS_RISC-V_LITEX_ARTY_A7_INCLUDE_BOARD_H */
diff --git a/boards/risc-v/litex/arty_a7/scripts/Make.defs
b/boards/risc-v/litex/arty_a7/scripts/Make.defs
new file mode 100644
index 0000000..960dda1
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/scripts/Make.defs
@@ -0,0 +1,96 @@
+############################################################################
+# boards/risc-v/litex/arty_a7/scripts/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+include ${TOPDIR}/.config
+include ${TOPDIR}/tools/Config.mk
+include ${TOPDIR}/arch/risc-v/src/rv32im/Toolchain.defs
+
+LDSCRIPT = ld.script
+
+ifeq ($(WINTOOL),y)
+ # Windows-native toolchains
+ DIRLINK = $(TOPDIR)/tools/copydir.sh
+ DIRUNLINK = $(TOPDIR)/tools/unlink.sh
+ MKDEP = $(TOPDIR)/tools/mkwindeps.sh
+ ARCHINCLUDES = -I. -isystem "${shell cygpath -w $(TOPDIR)/include}"
+ ARCHXXINCLUDES = -I. -isystem "${shell cygpath -w $(TOPDIR)/include}"
-isystem "${shell cygpath -w $(TOPDIR)/include/cxx}"
+ ARCHSCRIPT = -T "${shell cygpath -w
$(TOPDIR)/boards/$(CONFIG_ARCH)/$(CONFIG_ARCH_CHIP)/$(CONFIG_ARCH_BOARD)/scripts/$(LDSCRIPT)}"
+else
+ # Linux/Cygwin-native toolchain
+ MKDEP = $(TOPDIR)/tools/mkdeps$(HOSTEXEEXT)
+ ARCHINCLUDES = -I. -isystem $(TOPDIR)/include
+ ARCHXXINCLUDES = -I. -isystem $(TOPDIR)/include -isystem
$(TOPDIR)/include/cxx
+ ARCHSCRIPT =
-T$(TOPDIR)/boards/$(CONFIG_ARCH)/$(CONFIG_ARCH_CHIP)/$(CONFIG_ARCH_BOARD)/scripts/$(LDSCRIPT)
+endif
+
+CC = $(CROSSDEV)gcc
+CXX = $(CROSSDEV)g++
+CPP = $(CROSSDEV)gcc -E
+LD = $(CROSSDEV)ld
+STRIP = $(CROSSDEV)strip --strip-unneeded
+AR = $(ARCROSSDEV)ar rcs
+NM = $(ARCROSSDEV)nm
+OBJCOPY = $(CROSSDEV)objcopy
+OBJDUMP = $(CROSSDEV)objdump
+
+ARCHCCVERSION = ${shell $(CC) -v 2>&1 | sed -n '/^gcc version/p' | sed -e
's/^gcc version \([0-9\.]\)/\1/g' -e 's/[-\ ].*//g' -e '1q'}
+ARCHCCMAJOR = ${shell echo $(ARCHCCVERSION) | cut -d'.' -f1}
+
+ifeq ($(CONFIG_DEBUG_SYMBOLS),y)
+ ARCHOPTIMIZATION = -g
+ ASARCHCPUFLAGS += -Wa,-g
+endif
+
+MAXOPTIMIZATION = -Os
+
+ifneq ($(CONFIG_DEBUG_NOOPT),y)
+ ARCHOPTIMIZATION += $(MAXOPTIMIZATION) -fno-strict-aliasing
-fno-strength-reduce -fomit-frame-pointer
+endif
+
+ARCHCPUFLAGS = -march=rv32ima -mabi=ilp32
+ARCHCFLAGS = -fno-builtin -ffunction-sections -fdata-sections
+ARCHCXXFLAGS = -fno-builtin -fno-exceptions -fcheck-new -fno-rtti
+ARCHWARNINGS = -Wall -Wstrict-prototypes -Wshadow -Wundef
+ARCHWARNINGSXX = -Wall -Wshadow -Wundef
+ARCHDEFINES =
+ARCHPICFLAGS = -fpic -msingle-pic-base -mpic-register=r10
+
+CFLAGS = $(ARCHCFLAGS) $(ARCHWARNINGS) $(ARCHOPTIMIZATION) $(ARCHCPUFLAGS)
$(ARCHINCLUDES) $(ARCHDEFINES) $(EXTRADEFINES) -pipe
+CPICFLAGS = $(ARCHPICFLAGS) $(CFLAGS)
+CXXFLAGS = $(ARCHCXXFLAGS) $(ARCHWARNINGSXX) $(ARCHOPTIMIZATION)
$(ARCHCPUFLAGS) $(ARCHXXINCLUDES) $(ARCHDEFINES) $(EXTRADEFINES) -pipe
+CXXPICFLAGS = $(ARCHPICFLAGS) $(CXXFLAGS)
+CPPFLAGS = $(ARCHINCLUDES) $(ARCHDEFINES) $(EXTRADEFINES)
+AFLAGS += $(CFLAGS) -D__ASSEMBLY__ $(ASARCHCPUFLAGS)
+
+NXFLATLDFLAGS1 = -r -d -warn-common
+NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1)
-T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-pcrel.ld -no-check-sections
+LDNXFLATFLAGS = -e main -s 2048
+
+ASMEXT = .S
+OBJEXT = .o
+LIBEXT = .a
+EXEEXT =
+
+LDFLAGS += --gc-sections -melf32lriscv
+
+HOSTCC = gcc
+HOSTINCLUDES = -I.
+HOSTCFLAGS = -Wall -Wstrict-prototypes -Wshadow -Wundef -g -pipe
+HOSTLDFLAGS =
diff --git a/boards/risc-v/litex/arty_a7/scripts/ld.script
b/boards/risc-v/litex/arty_a7/scripts/ld.script
new file mode 100644
index 0000000..83ba995
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/scripts/ld.script
@@ -0,0 +1,93 @@
+/****************************************************************************
+ * boards/risc-v/litex/arty_a7/scripts/ld.script
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+MEMORY
+{
+ progmem (rx) : ORIGIN = 0xc0000000, LENGTH = 8M
+ sram (rwx) : ORIGIN = 0xc0800000, LENGTH = 256M - 8M
+}
+
+OUTPUT_ARCH("riscv")
+
+ENTRY(_stext)
+EXTERN(_vectors)
+SECTIONS
+{
+ .text : {
+ _stext = ABSOLUTE(.);
+ *(.vectors)
+ *(.text .text.*)
+ *(.fixup)
+ *(.gnu.warning)
+ *(.rodata .rodata.* .srodata .srodata.*)
+ *(.gnu.linkonce.t.*)
+ *(.glue_7)
+ *(.glue_7t)
+ *(.got)
+ *(.gcc_except_table)
+ *(.gnu.linkonce.r.*)
+ _etext = ABSOLUTE(.);
+ } > progmem
+
+ .init_section : ALIGN(4) {
+ _sinit = ABSOLUTE(.);
+ KEEP(*(.init_array .init_array.*))
+ _einit = ABSOLUTE(.);
+ } > progmem
+
+ _eronly = ABSOLUTE(.);
+
+ .data : ALIGN(4) {
+ _sdata = ABSOLUTE(.);
+ *(.data .data.*)
+ *(.sdata .sdata.* .sdata2.*)
+ *(.gnu.linkonce.d.*)
+ *(.gnu.linkonce.s.*)
+ CONSTRUCTORS
+ . = ALIGN(4);
+ _edata = ABSOLUTE(.);
+ } > sram AT > progmem
+
+ .bss : ALIGN(4) {
+ _sbss = ABSOLUTE(.);
+ *(.bss .bss.*)
+ *(.sbss .sbss.*)
+ *(.gnu.linkonce.b.*)
+ *(.gnu.linkonce.sb.*)
+ *(COMMON)
+ . = ALIGN(4);
+ _ebss = ABSOLUTE(.);
+ } > sram
+
+ /* Stabs debugging sections. */
+
+ .stab 0 : { *(.stab) }
+ .stabstr 0 : { *(.stabstr) }
+ .stab.excl 0 : { *(.stab.excl) }
+ .stab.exclstr 0 : { *(.stab.exclstr) }
+ .stab.index 0 : { *(.stab.index) }
+ .stab.indexstr 0 : { *(.stab.indexstr) }
+ .comment 0 : { *(.comment) }
+ .debug_abbrev 0 : { *(.debug_abbrev) }
+ .debug_info 0 : { *(.debug_info) }
+ .debug_line 0 : { *(.debug_line) }
+ .debug_pubnames 0 : { *(.debug_pubnames) }
+ .debug_aranges 0 : { *(.debug_aranges) }
+}
diff --git a/boards/risc-v/litex/arty_a7/src/Makefile
b/boards/risc-v/litex/arty_a7/src/Makefile
new file mode 100644
index 0000000..bc9d43f
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/src/Makefile
@@ -0,0 +1,29 @@
+############################################################################
+# boards/risc-v/litex/arty_a7/src/Makefile
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+-include $(TOPDIR)/Make.defs
+
+CSRCS = litex_bringup.c litex_boot.c
+
+ifeq ($(CONFIG_LIB_BOARDCTL),y)
+CSRCS += litex_appinit.c
+endif
+
+include $(TOPDIR)/boards/Board.mk
diff --git a/boards/risc-v/litex/arty_a7/src/arty_a7.h
b/boards/risc-v/litex/arty_a7/src/arty_a7.h
new file mode 100644
index 0000000..00e564b
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/src/arty_a7.h
@@ -0,0 +1,32 @@
+/****************************************************************************
+ * boards/risc-v/litex/arty_a7/src/arty_a7.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __BOARDS_RISCV_LITEX_ARTY_A7_SRC_ARTY_A7_H
+#define __BOARDS_RISCV_LITEX_ARTY_A7_SRC_ARTY_A7_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+int litex_bringup(void);
+
+#endif /* __BOARDS_RISCV_LITEX_ARTY_A7_SRC_ARTY_A7_H */
diff --git a/boards/risc-v/litex/arty_a7/src/litex_appinit.c
b/boards/risc-v/litex/arty_a7/src/litex_appinit.c
new file mode 100644
index 0000000..c2d92e8
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/src/litex_appinit.c
@@ -0,0 +1,75 @@
+/****************************************************************************
+ * boards/risc-v/litex/arty_a7/src/litex_appinit.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <errno.h>
+
+#include <nuttx/board.h>
+
+#include "litex.h"
+#include "arty_a7.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_app_initialize
+ *
+ * Description:
+ * Perform architecture specific initialization
+ *
+ * Input Parameters:
+ * arg - The boardctl() argument is passed to the board_app_initialize()
+ * implementation without modification. The argument has no
+ * meaning to NuttX; the meaning of the argument is a contract
+ * between the board-specific initialization logic and the
+ * matching application logic. The value cold be such things as a
+ * mode enumeration value, a set of DIP switch switch settings, a
+ * pointer to configuration data read from a file or serial FLASH,
+ * or whatever you would like to do with it. Every implementation
+ * should accept zero/NULL as a default configuration.
+ *
+ * Returned Value:
+ * Zero (OK) is returned on success; a negated errno value is returned on
+ * any failure to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int board_app_initialize(uintptr_t arg)
+{
+#ifdef CONFIG_BOARD_LATE_INITIALIZE
+ /* Board initialization already performed by board_late_initialize() */
+
+ return OK;
+#else
+ /* Perform board-specific initialization */
+
+ return litex_bringup();
+#endif
+}
diff --git a/boards/risc-v/litex/arty_a7/src/litex_boot.c
b/boards/risc-v/litex/arty_a7/src/litex_boot.c
new file mode 100644
index 0000000..43a3c7a
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/src/litex_boot.c
@@ -0,0 +1,57 @@
+/****************************************************************************
+ * boards/risc-v/litex/arty_a7/src/litex_boot.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+
+#include <nuttx/board.h>
+#include <arch/board/board.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: litex_boardinitialize
+ *
+ * Description:
+ * All LITEX architectures must provide the following entry point.
+ * This entry point is called early in the initialization -- after all
+ * memory has been configured and mapped but before any devices have been
+ * initialized.
+ *
+ ****************************************************************************/
+
+void litex_boardinitialize(void)
+{
+}
diff --git a/boards/risc-v/litex/arty_a7/src/litex_bringup.c
b/boards/risc-v/litex/arty_a7/src/litex_bringup.c
new file mode 100644
index 0000000..9b8e14f
--- /dev/null
+++ b/boards/risc-v/litex/arty_a7/src/litex_bringup.c
@@ -0,0 +1,61 @@
+/****************************************************************************
+ * boards/risc-v/litex/arty_a7/src/litex_bringup.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/mount.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <errno.h>
+
+#include <nuttx/board.h>
+#include <nuttx/input/buttons.h>
+
+#include "litex.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: litex_bringup
+ ****************************************************************************/
+
+int litex_bringup(void)
+{
+ int ret = OK;
+
+#ifdef CONFIG_FS_PROCFS
+ /* Mount the procfs file system */
+
+ ret = mount(NULL, "/proc", "procfs", 0, NULL);
+ if (ret < 0)
+ {
+ serr("ERROR: Failed to mount procfs at %s: %d\n", "/proc", ret);
+ }
+#endif
+
+ return ret;
+}
diff --git a/boards/risc-v/litex/drivers/Kconfig
b/boards/risc-v/litex/drivers/Kconfig
new file mode 100644
index 0000000..f72f3c0
--- /dev/null
+++ b/boards/risc-v/litex/drivers/Kconfig
@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
