confused kernel compressed code link address

[Chuck Huang]

hi Arn Ks,

thx for your reply.

So there is no global variables during the decompress process of kernel.

best regards

2014-05-12 14:06 GMT+08:00 Arun KS <getarunks at gmail.com>:
> Hi Chuck Huang,
>
> On Thu, May 8, 2014 at 5:25 PM, Chuck Huang <chuck.kernel at gmail.com> wrote:
>> Dear all,
>>
>> Now i am looking into kernel decompressed code, arch/arm/boot/compressed/head.S
>>
>> As i objdump arch/arm/boot/compressed/vmlinux, the start section address is 0x0.
>>
>> vmlinux.S
>> 373789| Disassembly of section .text:
>> 373790|
>> 373791| 00000000 <start>:
>> 373792| #endif
>>
>> if the code run in 0x8000 0000(which is DDR base address), but the
>> link address is zero, how it works ?
>
> The compressed/head.S code is position independent code. It can be
> loaded anywhere in RAM.
> There will not be reference to any labels directly. All the address
> references are done relative to PC.
>
> Thanks,
> Arun
>>
>> best regards
>>
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