[U-Boot] [PATCH] S3C6400/SMDK6400: fix stack_setup in start.S

"Seunghyeon Rhee (이승현)"
2009-11-02T02:46:05Z

Dear Minkyu Kang,

2009/11/2 Minkyu Kang <promsoft@gmail.com>:
> Dear Seunghyeon Rhee
>
> 2009/10/31 "Seunghyeon Rhee (???)" <seunghyeon@lpmtec.com>:
>> stack_setup is modified to initialize the stack on the correct address in
>> DRAM accroding to the typical memory configuration described in
>> README and the related CONFIG_* macro definitions. This makes macro
>> CONFIG_MEMORY_UPPER_CODE no longer necessry. This was introduced
>> and used only by this board for some unclear reason. The definition of
>> this macro is removed because it's not referenced elsewhere.
>>
>> Signed-off-by: Seunghyeon Rhee <seunghyeon@lpmtec.com>
>> ---
>> cpu/arm1176/start.S | 7 +------
>> include/configs/smdk6400.h | 2 --
>> 2 files changed, 1 insertions(+), 8 deletions(-)
>>
>> diff --git a/cpu/arm1176/start.S b/cpu/arm1176/start.S
>> index cb891df..1ecb3b9 100644
>> --- a/cpu/arm1176/start.S
>> +++ b/cpu/arm1176/start.S
>> @@ -241,16 +241,11 @@ mmu_enable:
>> skip_hw_init:
>> /* Set up the stack */
>> stack_setup:
>> -#ifdef CONFIG_MEMORY_UPPER_CODE
>> - ldr sp, =(CONFIG_SYS_UBOOT_BASE + CONFIG_SYS_UBOOT_SIZE - 0xc)
>> -#else
>> - ldr r0, _TEXT_BASE /* upper 128 KiB: relocated uboot */
>> + ldr r0, =CONFIG_SYS_UBOOT_BASE /* base of copy in
DRAM */
>
> this change is unnecessary, TEXT_BASE and CONFIG_SYS_UBOOT_BASE must
be same.

That's true for the body of U-Boot but not for SPL, where TEXT_BASE is
defined to be '0'.
Please refer to board/samsung/smdk6400/config.mk. On the other hand,
CONFIG_SYS_UBOOT_BASE is always dependent on DRAM's base.
In SPL, the base of the code should be '0' (the steppingstone memory)
and then the stack
is located below '0' - not a valid area. If SPL itself requires no
stack, it should be no
problem. But start.S calls nand_boot function right after the stack is
badly set up in the air.

My test results are like the following:
with CONFIG_MEMORY_UPPER_CODE defined : OK
with CONFIG_MEMORY_UPPER_CODE undefined :
- SPL bypassed (U-Boot downloaded to DRAM directly by USB monitor
program) : OK
- through SPL : Not OK (seems to fail for SPL downloading the code to DRAM)

I think CONFIG_MEMORY_UPPER_CODE was tested for the case it's defined
but not
enough for the case it's not defined. Would you check it again?

> btw, is there need CONFIG_SYS_UBOOT_BASE define?
>

If you are not sure, why did you use CONFIG_SYS_UBOOT_BASE for the
case CONFIG_MEMORY_UPPER_CODE is defined while you use TEXT_BASE
otherwise? I think the unnecessary macro definition here is not
CONFIG_..._BASE but
CONFIG_..._CODE. TEXT_BASE and CONFIG_..._BASE have their own meanings and
so both are necessary.

Best regards,
Seunghyeon

>> sub r0, r0, #CONFIG_SYS_MALLOC_LEN /* malloc
>> area */
>> sub r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /*
>> bdinfo */
>> sub sp, r0, #12 /* leave 3 words for abort-stack */
>>
>> -#endif
>> -
>> clear_bss:
>> ldr r0, _bss_start /* find start of bss segment */
>> ldr r1, _bss_end /* stop here */
>> diff --git a/include/configs/smdk6400.h b/include/configs/smdk6400.h
>> index f6e1221..f644cd2 100644
>> --- a/include/configs/smdk6400.h
>> +++ b/include/configs/smdk6400.h
>> @@ -49,8 +49,6 @@
>> #define CONFIG_ENABLE_MMU
>> #endif
>>
>> -#define CONFIG_MEMORY_UPPER_CODE
>> -
>> #define CONFIG_SETUP_MEMORY_TAGS
>> #define CONFIG_CMDLINE_TAG
>> #define CONFIG_INITRD_TAG
>> --
>> 1.6.2.5
>>
>>
>> --
>> Seunghyeon Rhee, Ph.D. / Director
>> LPM Technology Inc.
>> T +82-70-8255-6007 F +82-2-6442-6462
>> M +82-10-2790-0657
>> _______________________________________________
>> U-Boot mailing list
>> U-Boot at lists.denx.de
>> http://lists.denx.de/mailman/listinfo/u-boot
>>
>
> Thanks for patch :)
> Minkyu Kang
> --
> from. prom.
> www.promsoft.net
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
>

--
Seunghyeon Rhee, Ph.D. / Director
LPM Technology Inc.
T +82-70-8255-6007 F +82-2-6442-6462
M +82-10-2790-0657