Re: [dpdk-dev] [PATCH 1/5] pmdinfogen: fix cross compilation for ARM BE

[Hemant Agrawal <hemant.agrawal@nxp.com>]

Hi Neil/Bruce,

On 12/12/2017 12:28 AM, Neil Horman wrote:
> On Mon, Dec 11, 2017 at 12:40:32PM +0000, Bruce Richardson wrote:
>> On Thu, Nov 02, 2017 at 03:38:51PM +0530, Hemant Agrawal wrote:
>>> cross compiling DPDK for BE mode on ARM results into errors
>>>
>>> "PMDINFO portal/dpaa2_hw_dpio.o.pmd.c No drivers registered"
>>>
>>> Fixes: 98b0fdb0ffc6 ("pmdinfogen: add buildtools and pmdinfogen utility")
>>> Cc: Neil Horman <nhorman@tuxdriver.com>
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Jun Yang <jun.yang@nxp.com>
>>> Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
>>> ---
>>>  buildtools/pmdinfogen/pmdinfogen.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>
>> Comment could be a bit more specific about what the problem is and how
>> changing the hard-coded "32" fixes it.
>>
>> Haven't tested the cross compilation part myself, but this causes no
>> errors for 32-bit or 64-bit builds on my system. So, with some more
>> detail on the specifics of the fix in the commit message:
>>
>> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
>>
>
> I'm with Bruce.  I'd like to know exactly whats going on here.  I dont have an
> ARM system handy, so could you please post the errors that you are seeing here?
> Is ADDR_SIZE not defined on BE for ARM or some such?  That seems like it should
> be fixed, rather than this change.
>
> Neil
>

The original code hard codes the conversion for sh_size to 32, which is 
incorrect.

The sh_size can be "Elf32_Word    sh_size" for 32 bit and "Elf64_Xword 
sh_size" for 64 bit systems.

This causes the symtab_stop to have reduced size and thus find can fail.
	info->symtab_stop  = RTE_PTR_ADD(hdr, sechdrs[i].sh_offset + 
sechdrs[i].sh_size);

we fixed it by replacing the hardcoded 32 with ADDR_SIZE is better.

I don't have access to Intel BE compiler, so could not check behavior 
there. One of difference in my env is that I am doing cross compilation 
on intel-x86-64 machine.
I used the following BE compiler
https://releases.linaro.org/components/toolchain/binaries/6.4-2017.11/aarch64_be-linux-gnu/gcc-linaro-6.4.1-2017.11-x86_64_aarch64_be-linux-gnu.tar.xz


>>> diff --git a/buildtools/pmdinfogen/pmdinfogen.c b/buildtools/pmdinfogen/pmdinfogen.c
>>> index e73fc76..9119e52 100644
>>> --- a/buildtools/pmdinfogen/pmdinfogen.c
>>> +++ b/buildtools/pmdinfogen/pmdinfogen.c
>>> @@ -181,7 +181,7 @@ static int parse_elf(struct elf_info *info, const char *filename)
>>>  		sechdrs[i].sh_offset    =
>>>  			TO_NATIVE(endian, ADDR_SIZE, sechdrs[i].sh_offset);
>>>  		sechdrs[i].sh_size      =
>>> -			TO_NATIVE(endian, 32, sechdrs[i].sh_size);
>>> +			TO_NATIVE(endian, ADDR_SIZE, sechdrs[i].sh_size);
>>>  		sechdrs[i].sh_link      =
>>>  			TO_NATIVE(endian, 32, sechdrs[i].sh_link);
>>>  		sechdrs[i].sh_info      =
>>> --
>>> 2.7.4
>>>
>>
>