[U-Boot] [PATCH] arm: add 8-byte alignment for ABI compliance before board_init_f
Graeme Russ
graeme.russ at gmail.com
Fri Nov 12 09:50:56 CET 2010
On 12/11/10 18:19, Heiko Schocher wrote:
> Hello Reinhard,
>
> Reinhard Meyer wrote:
>> Dear Heiko Schocher,
>>> diff --git a/arch/arm/cpu/sa1100/start.S b/arch/arm/cpu/sa1100/start.S
>> Is bootflag ever used? If not, why not change the parameter to
>
> No.
>
>> give the gd address to board_init_f?
>>
>> ld r0, sp (whatever the exact assembly syntax for that would be)
>>
>> void board_init_f (gd_t *gd_addr)
>> ...
>> gd = gd_addr;
>
> I thought this too, but in arch/powerpc/lib/board.c it is used as bootflag,
> so I didn;t want to touch this ... but looking in arch/*/lib/board.c
> this first parameter is not always used as bootflag ... so I think
> that would be good ... opinions?
>
For x86, I use the parameter as a pointer to gd and put boot flags in gd:
void board_init_f (ulong gdp)
{
The memory layout for x86 is:
+--Top of Memory-+
| |
| Stack |
| |
+----------------+
| |
| Global Data |
| |
+----------------+
| |
| U-Boot Code |
| + Data |
| |
+----------------+ <-- dest_addr (see below)
| |
| BSS |
| |
+----------------+
| |
| malloc area |
| |
+----------------+
| |
| Free Memory |
/ /
So passing the pointer to gd also serves to calculate the relocation address:
/* Calculate destination RAM Address and relocation offset */
dest_addr = (void *)gdp - (bss_end - text_start);
rel_offset = dest_addr - text_start;
Regards,
Graeme
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