"Mark A. Greer" <[email protected]> writes:
> From: Lennert Buytenhek <[email protected]>
>
> On the Cirrus Logic ep93xx, system RAM isn't one nice physically
> contiguous region as it is on most SoCs, but it is spread out over
> between one and four memory banks.
>
> What's worse, RAM doesn't necessarily start at any fixed physical
> memory location. The start of RAM (PHYS_OFFSET) is not only board-
> specific, but on some boards also depends on jumper settings (whether
> async or sync boot mode is selected.)
>
> The attached patch adds the RUNTIME_PHYS_OFFSET config option, which,
> if selected, turns PHYS_OFFSET into a variable which is determined and
> set by __create_page_tables by looking at the current pc. This allows
> booting a single kernel image on all the different flavors of ep93xx
> boards. If the option isn't selected, there's zero impact.
>
> Signed-off-by: Lennert Buytenhek <[email protected]>
> Signed-off-by: Steve Chen <[email protected]>
> Signed-off-by: Mark A. Greer <[email protected]>
I think this one should go to l-a-k again. Maybe with a request from
yet another source, RMK will accept it.
Kevin
> ---
> arch/arm/Kconfig | 4 +++
> arch/arm/boot/compressed/Makefile | 9 ++----
> arch/arm/boot/compressed/head.S | 6 ++++
> arch/arm/include/asm/memory.h | 8 ++++++
> arch/arm/kernel/head.S | 38 +++++++++++++++++++--------
> arch/arm/kernel/setup.c | 14 +++++++++-
> arch/arm/mach-ep93xx/Makefile.boot | 1 -
> arch/arm/mach-ep93xx/include/mach/memory.h | 2 +
> 8 files changed, 63 insertions(+), 19 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 9bf3cb0..4043f02 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -188,6 +188,9 @@ config VECTORS_BASE
> help
> The base address of exception vectors.
>
> +config RUNTIME_PHYS_OFFSET
> + bool
> +
> source "init/Kconfig"
>
> source "kernel/Kconfig.freezer"
> @@ -272,6 +275,7 @@ config ARCH_EP93XX
> select HAVE_CLK
> select COMMON_CLKDEV
> select ARCH_REQUIRE_GPIOLIB
> + select RUNTIME_PHYS_OFFSET
> help
> This enables support for the Cirrus EP93xx series of CPUs.
>
> diff --git a/arch/arm/boot/compressed/Makefile
> b/arch/arm/boot/compressed/Makefile
> index fbe5eef..b0d7771 100644
> --- a/arch/arm/boot/compressed/Makefile
> +++ b/arch/arm/boot/compressed/Makefile
> @@ -74,13 +74,10 @@ endif
> EXTRA_CFLAGS := -fpic -fno-builtin
> EXTRA_AFLAGS := -Wa,-march=all
>
> -# Supply ZRELADDR, INITRD_PHYS and PARAMS_PHYS to the decompressor via
> -# linker symbols. We only define initrd_phys and params_phys if the
> -# machine class defined the corresponding makefile variable.
> +# Supply ZRELADDR and PARAMS_PHYS to the decompressor via linker
> +# symbols. We only define params_phys if the machine class defined
> +# the corresponding makefile variable.
> LDFLAGS_vmlinux := --defsym zreladdr=$(ZRELADDR)
> -ifneq ($(INITRD_PHYS),)
> -LDFLAGS_vmlinux += --defsym initrd_phys=$(INITRD_PHYS)
> -endif
> ifneq ($(PARAMS_PHYS),)
> LDFLAGS_vmlinux += --defsym params_phys=$(PARAMS_PHYS)
> endif
> diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
> index 77d6142..e19623c 100644
> --- a/arch/arm/boot/compressed/head.S
> +++ b/arch/arm/boot/compressed/head.S
> @@ -156,6 +156,12 @@ not_angel:
> .text
> adr r0, LC0
> ldmia r0, {r1, r2, r3, r4, r5, r6, ip, sp}
> +#ifdef CONFIG_RUNTIME_PHYS_OFFSET
> + and r10, pc, #0xf0000000 @ fix up zreladdr
> + and r4, r4, #0x0fffffff
> + add r4, r4, r10
> +#endif
> +
> subs r0, r0, r1 @ calculate the delta offset
>
> @ if delta is zero, we are
> diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
> index 0202a7c..04be0b5 100644
> --- a/arch/arm/include/asm/memory.h
> +++ b/arch/arm/include/asm/memory.h
> @@ -63,6 +63,14 @@
> */
> #define IOREMAP_MAX_ORDER 24
>
> +/*
> + * PHYS_OFFSET determined at run time?
> + */
> +#if defined(CONFIG_RUNTIME_PHYS_OFFSET) && !defined(__ASSEMBLY__)
> +extern unsigned long phys_offset;
> +#define PHYS_OFFSET (phys_offset)
> +#endif
> +
> #else /* CONFIG_MMU */
>
> /*
> diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
> index 21e17dc..9f70d0a 100644
> --- a/arch/arm/kernel/head.S
> +++ b/arch/arm/kernel/head.S
> @@ -22,12 +22,13 @@
> #include <asm/thread_info.h>
> #include <asm/system.h>
>
> +#ifndef CONFIG_RUNTIME_PHYS_OFFSET
> #if (PHYS_OFFSET & 0x001fffff)
> #error "PHYS_OFFSET must be at an even 2MiB boundary!"
> #endif
> +#endif
>
> #define KERNEL_RAM_VADDR (PAGE_OFFSET + TEXT_OFFSET)
> -#define KERNEL_RAM_PADDR (PHYS_OFFSET + TEXT_OFFSET)
>
>
> /*
> @@ -44,8 +45,8 @@
> .globl swapper_pg_dir
> .equ swapper_pg_dir, KERNEL_RAM_VADDR - 0x4000
>
> - .macro pgtbl, rd
> - ldr \rd, =(KERNEL_RAM_PADDR - 0x4000)
> + .macro pgtbl, rd, phys_offset
> + add \rd, \phys_offset, #(TEXT_OFFSET - 0x4000)
> .endm
>
> #ifdef CONFIG_XIP_KERNEL
> @@ -210,9 +211,26 @@ ENDPROC(__turn_mmu_on)
> * Returns:
> * r0, r3, r6, r7 corrupted
> * r4 = physical page table address
> + * r5 = PHYS_OFFSET
> */
> __create_page_tables:
> - pgtbl r4 @ page table address
> +#ifdef CONFIG_RUNTIME_PHYS_OFFSET
> + adr r5, stext
> + sub r5, r5, #TEXT_OFFSET @ r5 = phys_offset
> + ldr r4, =0xfff00000
> + and r5, r5, r4
> +
> + ldr r4, =(phys_offset - PAGE_OFFSET)
> + add r4, r4, r5
> + str r5, [r4] @ save phys_offset
> +#else
> + mov r5, #(PHYS_OFFSET & 0xff000000)
> + .if (PHYS_OFFSET & 0x00f00000)
> + orr r5, r5, #(PHYS_OFFSET & 0x00f00000)
> + .endif
> +#endif
> +
> + pgtbl r4, r5 @ r4 = page table address
>
> /*
> * Clear the 16K level 1 swapper page table
> @@ -257,10 +275,11 @@ __create_page_tables:
> /*
> * Map some ram to cover our .data and .bss areas.
> */
> - orr r3, r7, #(KERNEL_RAM_PADDR & 0xff000000)
> - .if (KERNEL_RAM_PADDR & 0x00f00000)
> - orr r3, r3, #(KERNEL_RAM_PADDR & 0x00f00000)
> + add r3, r5, #(TEXT_OFFSET & 0xff000000) @ r5 = PHYS_OFFSET
> + .if (TEXT_OFFSET & 0x00f00000)
> + add r3, r3, #(TEXT_OFFSET & 0x00f00000)
> .endif
> + orr r3, r3, r7
> add r0, r4, #(KERNEL_RAM_VADDR & 0xff000000) >> 18
> str r3, [r0, #(KERNEL_RAM_VADDR & 0x00f00000) >> 18]!
> ldr r6, =(_end - 1)
> @@ -276,10 +295,7 @@ __create_page_tables:
> * Then map first 1MB of ram in case it contains our boot params.
> */
> add r0, r4, #PAGE_OFFSET >> 18
> - orr r6, r7, #(PHYS_OFFSET & 0xff000000)
> - .if (PHYS_OFFSET & 0x00f00000)
> - orr r6, r6, #(PHYS_OFFSET & 0x00f00000)
> - .endif
> + orr r6, r7, r5
> str r6, [r0]
>
> #ifdef CONFIG_DEBUG_LL
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index 7049815..99c2a53 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -63,6 +63,16 @@ __setup("fpe=", fpe_setup);
> extern void paging_init(struct machine_desc *desc);
> extern void reboot_setup(char *str);
>
> +#ifdef CONFIG_RUNTIME_PHYS_OFFSET
> +/*
> + * The assignment is here solely to prevent this variable from ending
> + * up in bss. As the early startup code writes to it, we don't want it
> + * to be zeroed again later.
> + */
> +unsigned long phys_offset = 0xdeadbeef;
> +EXPORT_SYMBOL(phys_offset);
> +#endif
> +
> unsigned int processor_id;
> EXPORT_SYMBOL(processor_id);
> unsigned int __machine_arch_type;
> @@ -663,7 +673,7 @@ static struct init_tags {
> { tag_size(tag_core), ATAG_CORE },
> { 1, PAGE_SIZE, 0xff },
> { tag_size(tag_mem32), ATAG_MEM },
> - { MEM_SIZE, PHYS_OFFSET },
> + { MEM_SIZE, 0 },
> { 0, ATAG_NONE }
> };
>
> @@ -684,6 +694,8 @@ void __init setup_arch(char **cmdline_p)
> struct machine_desc *mdesc;
> char *from = default_command_line;
>
> + init_tags.mem.start = PHYS_OFFSET;
> +
> setup_processor();
> mdesc = setup_machine(machine_arch_type);
> machine_name = mdesc->name;
> diff --git a/arch/arm/mach-ep93xx/Makefile.boot
> b/arch/arm/mach-ep93xx/Makefile.boot
> index d5561ad..574a4aa 100644
> --- a/arch/arm/mach-ep93xx/Makefile.boot
> +++ b/arch/arm/mach-ep93xx/Makefile.boot
> @@ -1,2 +1 @@
> zreladdr-y := 0x00008000
> -params_phys-y := 0x00000100
> diff --git a/arch/arm/mach-ep93xx/include/mach/memory.h
> b/arch/arm/mach-ep93xx/include/mach/memory.h
> index 5c80c3c..66e3b68 100644
> --- a/arch/arm/mach-ep93xx/include/mach/memory.h
> +++ b/arch/arm/mach-ep93xx/include/mach/memory.h
> @@ -5,6 +5,8 @@
> #ifndef __ASM_ARCH_MEMORY_H
> #define __ASM_ARCH_MEMORY_H
>
> +#ifndef CONFIG_RUNTIME_PHYS_OFFSET
> #define PHYS_OFFSET UL(0x00000000)
> +#endif
>
> #endif
> --
> 1.6.0.3
>
>
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