[PATCH] riscv: Fix efi header for RV32

[Heinrich Schuchardt]

Am 14. Oktober 2020 03:03:28 MESZ schrieb Bin Meng <bmeng.cn at gmail.com>:
>On Wed, Oct 14, 2020 at 3:23 AM Atish Patra <atish.patra at wdc.com>
>wrote:
>>
>> RV32 should use PE32 format instead of PE32+ as the efi header
>format.
>> This requires following changes
>> 1. A different header magic value
>> 2. An additional parameter known as BaseOfData. Currently, it is set
>to
>>    zero in absence of any usage.
>>
>> Signed-off-by: Atish Patra <atish.patra at wdc.com>
>> ---
>>  arch/riscv/lib/crt0_riscv_efi.S | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/lib/crt0_riscv_efi.S
>b/arch/riscv/lib/crt0_riscv_efi.S
>> index 87fe1e56f906..4aaa49ad0777 100644
>> --- a/arch/riscv/lib/crt0_riscv_efi.S
>> +++ b/arch/riscv/lib/crt0_riscv_efi.S
>> @@ -15,11 +15,13 @@
>>  #define SAVE_LONG(reg, idx)    sd      reg, (idx*SIZE_LONG)(sp)
>>  #define LOAD_LONG(reg, idx)    ld      reg, (idx*SIZE_LONG)(sp)
>>  #define PE_MACHINE     IMAGE_FILE_MACHINE_RISCV64
>> +#define PE_MAGIC        IMAGE_NT_OPTIONAL_HDR64_MAGIC
>
>nits: the indentation seems to be incorrect
>
>>  #else
>>  #define SIZE_LONG      4
>>  #define SAVE_LONG(reg, idx)    sw      reg, (idx*SIZE_LONG)(sp)
>>  #define LOAD_LONG(reg, idx)    lw      reg, (idx*SIZE_LONG)(sp)
>>  #define PE_MACHINE     IMAGE_FILE_MACHINE_RISCV32
>> +#define PE_MAGIC        IMAGE_NT_OPTIONAL_HDR32_MAGIC
>>  #endif
>>
>>
>> @@ -48,7 +50,7 @@ coff_header:
>>                  IMAGE_FILE_LOCAL_SYMS_STRIPPED | \
>>                  IMAGE_FILE_DEBUG_STRIPPED)
>>  optional_header:
>> -       .short  IMAGE_NT_OPTIONAL_HDR64_MAGIC   /* PE32+ format */
>
>nits: PE32(+) ?
>
>> +       .short  PE_MAGIC                        /* PE32+ format */
>>         .byte   0x02                            /* MajorLinkerVersion
>*/
>>         .byte   0x14                            /* MinorLinkerVersion
>*/
>>         .long   _edata - _start                 /* SizeOfCode */
>> @@ -56,6 +58,9 @@ optional_header:
>>         .long   0                               /*
>SizeOfUninitializedData */
>>         .long   _start - ImageBase              /*
>AddressOfEntryPoint */
>>         .long   _start - ImageBase              /* BaseOfCode */
>> +#if __riscv_xlen == 32
>> +       .long   0                               /* BaseOfData */
>> +#endif
>>

The PE32 header has to be 96 bytes long, the PE32+ header 112 bytes long.

See https://docs.microsoft.com/en-us/windows/win32/debug/pe-format

Best regards

Heinrich


>>  extra_header_fields:
>>         .quad   0                               /* ImageBase */
>
>Looks good otherwise
>Reviewed-by: Bin Meng <bin.meng at windriver.com>