[PATCH] riscv: Fix efi header for RV32

[Leo Liang]

Hi Atish and Heinrich,

On Tue, Oct 13, 2020 at 12:23:31PM -0700, Atish Patra 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>
> Reviewed-by: Bin Meng <bin.meng at windriver.com>
> Reviewed-by: Rick Chen <rick at andestech.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
>  #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 */
> +	.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
>  
>  extra_header_fields:
>  	.quad	0				/* ImageBase */

diff --git a/arch/riscv/lib/crt0_riscv_efi.S b/arch/riscv/lib/crt0_riscv_efi.S
index 4aaa49ad07..f47c4a6d82 100644
--- a/arch/riscv/lib/crt0_riscv_efi.S
+++ b/arch/riscv/lib/crt0_riscv_efi.S
@@ -63,7 +63,11 @@ optional_header:
 #endif

 extra_header_fields:
+#if __riscv_xlen == 32
+       .long   0                               /* ImageBase */
+#else if
        .quad   0                               /* ImageBase */
+#endif
        .long   0x20                            /* SectionAlignment */
        .long   0x8                             /* FileAlignment */
        .short  0                               /* MajorOperatingSystemVersion */
@@ -83,10 +87,17 @@ extra_header_fields:
        .long   0                               /* CheckSum */
        .short  IMAGE_SUBSYSTEM_EFI_APPLICATION /* Subsystem */
        .short  0                               /* DllCharacteristics */
+#if __riscv_xlen == 32
+       .long   0                               /* SizeOfStackReserve */
+       .long   0                               /* SizeOfStackCommit */
+       .long   0                               /* SizeOfHeapReserve */
+       .long   0                               /* SizeOfHeapCommit */
+#else if
        .quad   0                               /* SizeOfStackReserve */
        .quad   0                               /* SizeOfStackCommit */
        .quad   0                               /* SizeOfHeapReserve */
        .quad   0                               /* SizeOfHeapCommit */
+#endif
        .long   0                               /* LoaderFlags */
        .long   0x6                             /* NumberOfRvaAndSizes */

Based on Atish's patch, 
would the above modification fit more closely to the specification that Heinrich provided ?

Best regards,
Leo