[PATCH 1/1] efi_loader: fix building aarch64 EFI binaries

[Ilias Apalodimas]

Hi Heinrich 

On Sat, Dec 31, 2022 at 12:03:45PM +0100, Heinrich Schuchardt wrote:
> While our EFI binaries execute without problems on EDK II they crash on
> a Lenovo X13s. Let our binaries look more like what EDK II produces:
> 
> * move all writable data to a .data section
> * align sections to 4 KiB boundaries (matching EFI page size)
> 
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  arch/arm/lib/crt0_aarch64_efi.S  | 35 ++++++++++++++++++++++----------
>  arch/arm/lib/elf_aarch64_efi.lds |  6 ++++--
>  2 files changed, 28 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/arm/lib/crt0_aarch64_efi.S b/arch/arm/lib/crt0_aarch64_efi.S
> index b4fc263adf..52b2482efe 100644
> --- a/arch/arm/lib/crt0_aarch64_efi.S
> +++ b/arch/arm/lib/crt0_aarch64_efi.S
> @@ -25,7 +25,7 @@ pe_header:
>  	.long	IMAGE_NT_SIGNATURE		/* 'PE' */
>  coff_header:
>  	.short	IMAGE_FILE_MACHINE_ARM64	/* AArch64 */
> -	.short	2				/* nr_sections */
> +	.short	3				/* nr_sections */
>  	.long	0				/* TimeDateStamp */
>  	.long	0				/* PointerToSymbolTable */
>  	.long	0				/* NumberOfSymbols */
> @@ -40,7 +40,7 @@ optional_header:
>  	.short	IMAGE_NT_OPTIONAL_HDR64_MAGIC	/* PE32+ format */
>  	.byte	0x02				/* MajorLinkerVersion */
>  	.byte	0x14				/* MinorLinkerVersion */
> -	.long	_edata - _start			/* SizeOfCode */
> +	.long	_etext - _start			/* SizeOfCode */
>  	.long	0				/* SizeOfInitializedData */
>  	.long	0				/* SizeOfUninitializedData */
>  	.long	_start - ImageBase		/* AddressOfEntryPoint */
> @@ -48,7 +48,7 @@ optional_header:
>  
>  extra_header_fields:
>  	.quad	0				/* ImageBase */
> -	.long	0x200				/* SectionAlignment */
> +	.long	0x1000				/* SectionAlignment */
>  	.long	0x200				/* FileAlignment */
>  	.short	0				/* MajorOperatingSystemVersion */
>  	.short	0				/* MinorOperatingSystemVersion */
> @@ -107,18 +107,31 @@ section_table:
>  	.byte	0
>  	.byte	0
>  	.byte	0			/* end of 0 padding of section name */
> -	.long	_edata - _start		/* VirtualSize */
> +	.long	_etext - _start		/* VirtualSize */
>  	.long	_start - ImageBase	/* VirtualAddress */
> -	.long	_edata - _start		/* SizeOfRawData */
> +	.long	_etext - _start		/* SizeOfRawData */
>  	.long	_start - ImageBase	/* PointerToRawData */
> +	.long	0			/* PointerToRelocations */
> +	.long	0			/* PointerToLineNumbers */
> +	.short	0			/* NumberOfRelocations */
> +	.short	0			/* NumberOfLineNumbers */
> +	.long	0x60000020		/* Characteristics (section flags) */

Can we replace the 0x60000020 magic here with defines from
include/asm-generic/pe.h?

>  
> -	.long	0		/* PointerToRelocations (0 for executables) */
> -	.long	0		/* PointerToLineNumbers (0 for executables) */
> -	.short	0		/* NumberOfRelocations  (0 for executables) */
> -	.short	0		/* NumberOfLineNumbers  (0 for executables) */
> -	.long	0xe0500020	/* Characteristics (section flags) */
> +	.ascii	".data"
> +	.byte	0
> +	.byte	0
> +	.byte	0			/* end of 0 padding of section name */
> +	.long	_data_size		/* VirtualSize */
> +	.long	_data - ImageBase	/* VirtualAddress */
> +	.long	_data_size		/* SizeOfRawData */
> +	.long	_data - ImageBase	/* PointerToRawData */
> +	.long	0			/* PointerToRelocations */
> +	.long	0			/* PointerToLineNumbers */
> +	.short	0			/* NumberOfRelocations */
> +	.short	0			/* NumberOfLineNumbers */
> +	.long	0xc0000040		/* Characteristics (section flags) */

Same here

>  
> -	.align		9
> +	.align		12
>  _start:
>  	stp		x29, x30, [sp, #-32]!
>  	mov		x29, sp
> diff --git a/arch/arm/lib/elf_aarch64_efi.lds b/arch/arm/lib/elf_aarch64_efi.lds
> index c0604dad46..ffc6f6e604 100644
> --- a/arch/arm/lib/elf_aarch64_efi.lds
> +++ b/arch/arm/lib/elf_aarch64_efi.lds
> @@ -18,11 +18,13 @@ SECTIONS
>  		*(.gnu.linkonce.t.*)
>  		*(.srodata)
>  		*(.rodata*)
> +		. = ALIGN(16);
> +		*(.dynamic);
>  		. = ALIGN(512);
>  	}
>  	_etext = .;
>  	_text_size = . - _text;
> -	.dynamic  : { *(.dynamic) }
> +	. = ALIGN(4096);
>  	.data : {
>  		_data = .;
>  		*(.sdata)
> @@ -48,11 +50,11 @@ SECTIONS
>  		_bss_end = .;
>  		_edata = .;
>  	}
> +	_data_size = _edata - _data;
>  	.rela.dyn : { *(.rela.dyn) }
>  	.rela.plt : { *(.rela.plt) }
>  	.rela.got : { *(.rela.got) }
>  	.rela.data : { *(.rela.data) *(.rela.data*) }
> -	_data_size = . - _etext;
>  
>  	. = ALIGN(4096);
>  	.dynsym   : { *(.dynsym) }
> -- 
> 2.37.2
> 

Regards
/Ilias