[GSOC2013] Dynamic object file loading

[Gedare Bloom]

Administrative note: I made your google doc private and shared it
explicitly with Chris (and a handful of others).

On Sun, Apr 21, 2013 at 11:45 PM, Chris Johns <chrisj at rtems.org> wrote:
> Peng Fan wrote:
>>
>>
>> I add the following code to ignore ARM.attributes and ARM.exidx sections
>> which are contained in xa.c x-long.*.c and rtld.prelink. Not sure whether
>> this is right or not, but when compling rtl target, all is passed. This
>> may looks not a good way.
>
>
> I have not looked into the best way to add this support. I suspect updating
> elftoolchain is the best solution but I am not sure how.
>
>> diff --git a/elftoolchain/libelf/elf_data.c
>> b/elftoolchain/libelf/elf_data.c
>> index 5ac6453..a6e17ae 100644
>> --- a/elftoolchain/libelf/elf_data.c
>> +++ b/elftoolchain/libelf/elf_data.c
>> @@ -87,9 +87,20 @@ elf_getdata(Elf_Scn *s, Elf_Data *d)
>> return (NULL);
>> }
>> +if (sh_type == 0x70000003 || sh_type == 0x70000001) {
>> +if ((d = _libelf_allocate_data(s)) == NULL)
>>
>> +return (NULL);
>> +d->d_buf = 0;
>> +d->d_size = 0;
>> +return (d);
>>
>> +}
>> +  //printf("freenix %x %x\n", (sh_type), ELF_T_FIRST);
>> +
>>
>> Now, I am trying to make the rtld run on my Tiny6410 board. It does run,
>> but rap load ./x.rap fails. Error msg is:
>> rtl: reloc unknown: sym = 0, type = 29, offset = 0x4, contents =
>> 0xeafffffe
>> error: loading: (22) .text: Unsupported relocation type 29 in non-PLT
>> relocations
>>
>> Type 29 in elf for arm is R_TYPE_JUMP24 which is not supported in
>> rtl-target side, thus error occurs. I am trying to add this to target
>> side.
>
>
> Excellent. This now the real task.
>
>>
>> I have finished a proposal draft. It is here
>>
>> <https://docs.google.com/document/d/1HBkRU7_kUOvoiCQWTUxQ151kvX--3x_E7r0rTerxYbo/edit?usp=sharing>.
>>
>> You can edit it. Hope you can give me some suggestions. On the target
>> side, I know the main work that I should done is in rtl-mdreloc-arm.c,
>> but on the host side, It seems all have been done.  Thnnks.
>
>
> This is just a part of the project. The ARM relocation may not be enough. I
> will think about this.
>
>
> Chris
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