On 13 September 2013 15:58, alex.ben...@linaro.org wrote:
From: Alex Bennée a...@bennee.com
Commit 9b8c69243 broke the ability to boot the kernel as the value
returned by unassigned_mem_read returned non-zero and left the kernel
looping forever waiting for it to change (see integrator_led_set in
the kernel code).
Relying on a varying implementation detail is incorrect anyway so this
introduces a memory region to emulate the debug/led region on the
integrator board. It is currently a basic stub as I have no idea what the
behaviour of this region should be
See the integrator board documentation:
http://infocenter.arm.com/help/topic/com.arm.doc.dui0159b/Babbfijf.html
so for now it simply returns 0's as
the old unassigned_mem_read did.
---
hw/arm/integratorcp.c | 2 ++
hw/misc/Makefile.objs | 1 +
hw/misc/arm_intdbg.c | 90
+++
3 files changed, 93 insertions(+)
create mode 100644 hw/misc/arm_intdbg.c
diff --git a/hw/arm/integratorcp.c b/hw/arm/integratorcp.c
index 2ef93ed..e5d07c4 100644
--- a/hw/arm/integratorcp.c
+++ b/hw/arm/integratorcp.c
@@ -446,6 +446,7 @@ static void icp_control_init(hwaddr base)
}
+
Stray whitespace change.
/* Board init. */
static struct arm_boot_info integrator_binfo = {
@@ -508,6 +509,7 @@ static void integratorcp_init(QEMUMachineInitArgs *args)
icp_control_init(0xcb00);
sysbus_create_simple(pl050_keyboard, 0x1800, pic[3]);
sysbus_create_simple(pl050_mouse, 0x1900, pic[4]);
+sysbus_create_simple(integrator_dbg, 0x1a00, 0);
sysbus_create_varargs(pl181, 0x1c00, pic[23], pic[24], NULL);
if (nd_table[0].used)
smc91c111_init(nd_table[0], 0xc800, pic[27]);
diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 2578e29..e2c84a3 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -22,6 +22,7 @@ obj-$(CONFIG_LINUX) += vfio.o
endif
obj-$(CONFIG_REALVIEW) += arm_sysctl.o
+obj-y += arm_intdbg.o
The device isn't depending on anything target specific
so it can go in common-obj-. It needs its own
CONFIG_INTEGRATOR_DBG in default-configs/arm-softmmu.mak
so you can make it common-obj-$(CONFIG_INTEGRATOR_DBG) +=.
obj-$(CONFIG_A9SCU) += a9scu.o
obj-$(CONFIG_NSERIES) += cbus.o
obj-$(CONFIG_ECCMEMCTL) += eccmemctl.o
diff --git a/hw/misc/arm_intdbg.c b/hw/misc/arm_intdbg.c
new file mode 100644
index 000..1f21447
--- /dev/null
+++ b/hw/misc/arm_intdbg.c
@@ -0,0 +1,90 @@
+/*
+ * LED, Switch and Debug control registers for ARM Integrator Boards
+ *
+ * This currently is a stub for this functionality written with
+ * reference to what the Linux kernel looks at. Previously we relied
+ * on the behaviour of unassigned_mem_read() in the core.
+ *
+ * Written by Alex Bennée
+ *
+ * This code is licensed under the GPL.
Would be nice to give a specific version of the GPL...
(2 or 2 or later are your two basic options.)
+ */
+
+#include hw/hw.h
+#include hw/sysbus.h
+#include exec/address-spaces.h
+
+#define TYPE_ARM_INTDBG integrator_dbg
+#define ARM_INTDBG(obj) \
+OBJECT_CHECK(arm_intdbg_state, (obj), TYPE_ARM_INTDBG)
+
+typedef struct {
+SysBusDevice parent_obj;
+MemoryRegion iomem;
+
+uint32_t alpha;
+uint32_t leds;
+uint32_t switches;
+} arm_intdbg_state;
CODING_STYLE says type names should be camelcase, so
ARMIntDbgState.
+
+static uint64_t dbg_control_read(void *opaque, hwaddr offset,
+ unsigned size)
+{
+switch (offset 2) {
+case 0: /* ALPHA */
+return 0;
+case 1: /* LEDS */
+return 0;
+case 2: /* SWITCHES */
+return 0;
You could log these with qemu_log_mask(LOG_UNIMP, ...)
+default:
+hw_error(dbg_control_read: Bad offset %x\n, (int)offset);
Don't hw_error() for something a guest can provoke.
You can just log the info to the debug log (if the
user has enabled it) and press on:
qemu_log_mask(LOG_GUEST_ERROR,
dbg_control_read: Bad offset %x\n, (int)offset);
+return 0;
+}
+}
+
+static void dbg_control_write(void *opaque, hwaddr offset,
+ uint64_t value, unsigned size)
+{
+switch (offset 2) {
+case 1: /* ALPHA */
+case 2: /* LEDS */
+case 3: /* SWITCHES */
+/* Nothing interesting implemented yet. */
+break;
+default:
+hw_error(dbg_control_write: Bad offset %x\n, (int)offset);
Same remarks as above about logging unimplemented
and bad guest behaviour.
+}
+}
+
+static const MemoryRegionOps dbg_control_ops = {
+.read = dbg_control_read,
+.write = dbg_control_write,
+.endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static void dbg_control_init(Object *obj)
+{
+SysBusDevice *sd = SYS_BUS_DEVICE(obj);
+arm_intdbg_state *s = ARM_INTDBG(obj);
+memory_region_init_io(s-iomem, NULL,
