[U-Boot] [BUG ] efiloader: incorrect creation of *.efi file

[Heinrich Schuchardt]

On 1/19/19 12:55 PM, Heinrich Schuchardt wrote:
> On 1/19/19 11:21 AM, Heinrich Schuchardt wrote:
>> Hello Alex,
>>
>> bootefi hello fails since  5be444d14b380b210b246aa73dd5a111e4b1f80d
>> efi_loader: consistent build flags for EFI applications
>>
>> The problem is caused by incorrect entry point information in the EFI
>> binary:
>>
>> Actual positions in EFI file:
>> 0x178 hw_memcmp.constprop.0
>> 0x1a8 efi_main
>>
>> Header information in EFI file
>> (using https://github.com/xypron/efi_analyzer):
>>
>> BaseOfCode=0x148
>> AddressOfEntryPoint=0x148
>>
>> So AddressOfEntryPoint is not pointing to efi_main().
> 
> In arch/arm/lib/crt0_aarch64_efi.S we define AddressOfEntryPoint to
> point to _start. _start() calls _relocate().
> 
> We already do a relocation in efi_load_pe(). I cannot understand why the
> code should be relocated twice.
> 
> Best regards
> 
> Heinrich
> 

Though I still do not understand why we call relocation twice the real
bug seems to stem form a call to a non-existent memcpy() function.

See address 0x74 of the disassembly.

https://gcc.gnu.org/onlinedocs/gcc/Standards.html teaches:
"GCC requires the freestanding environment provide memcpy, memmove,
memset and memcmp."

        struct efi_simple_text_output_protocol *con_out = systable->con_out;
  60:   f940203b        ldr     x27, [x1, #64]
        u16 rev[] = L"0.0.0";
  64:   aa1303e0        mov     x0, x19
        struct efi_boot_services *boottime = systable->boottime;
  68:   f940303a        ldr     x26, [x1, #96]
        u16 rev[] = L"0.0.0";
  6c:   90000001        adrp    x1, 0 <hw_memcmp.constprop.0>
  70:   91000021        add     x1, x1, #0x0
  74:   94000000        bl      0 <memcpy>

        /* UEFI requires CR LF */
        con_out->output_string(con_out, L"Hello, world!\r\n");
  78:   f9400762        ldr     x2, [x27, #8]
  7c:   90000001        adrp    x1, 0 <hw_memcmp.constprop.0>
  80:   aa1b03e0        mov     x0, x27
  84:   91000021        add     x1, x1, #0x0
  88:   d63f0040        blr     x2


Regards

Heinrich