gnu-efi/gnuefi/crt0-efi-arm.S

146 lines
4.1 KiB
ArmAsm

/*
* crt0-efi-arm.S - PE/COFF header for ARM EFI applications
*
* Copright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice and this list of conditions, without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License as published by the Free Software Foundation;
* either version 2 of the License, or (at your option) any later version.
*/
.section .text.head
/*
* Magic "MZ" signature for PE/COFF
*/
.globl ImageBase
ImageBase:
.ascii "MZ"
.skip 58 // 'MZ' + pad + offset == 64
.long pe_header - ImageBase // Offset to the PE header.
pe_header:
.ascii "PE"
.short 0
coff_header:
.short 0x1c2 // Mixed ARM/Thumb
.short 2 // nr_sections
.long 0 // TimeDateStamp
.long 0 // PointerToSymbolTable
.long 1 // NumberOfSymbols
.short section_table - optional_header // SizeOfOptionalHeader
.short 0x306 // Characteristics.
// IMAGE_FILE_32BIT_MACHINE |
// IMAGE_FILE_DEBUG_STRIPPED |
// IMAGE_FILE_EXECUTABLE_IMAGE |
// IMAGE_FILE_LINE_NUMS_STRIPPED
optional_header:
.short 0x10b // PE32+ format
.byte 0x02 // MajorLinkerVersion
.byte 0x14 // MinorLinkerVersion
.long _edata - _start // SizeOfCode
.long 0 // SizeOfInitializedData
.long 0 // SizeOfUninitializedData
.long _start - ImageBase // AddressOfEntryPoint
.long _start - ImageBase // BaseOfCode
.long 0 // BaseOfData
extra_header_fields:
.long 0 // ImageBase
.long 0x20 // SectionAlignment
.long 0x8 // FileAlignment
.short 0 // MajorOperatingSystemVersion
.short 0 // MinorOperatingSystemVersion
.short 0 // MajorImageVersion
.short 0 // MinorImageVersion
.short 0 // MajorSubsystemVersion
.short 0 // MinorSubsystemVersion
.long 0 // Win32VersionValue
.long _edata - ImageBase // SizeOfImage
// Everything before the kernel image is considered part of the header
.long _start - ImageBase // SizeOfHeaders
.long 0 // CheckSum
.short EFI_SUBSYSTEM // Subsystem
.short 0 // DllCharacteristics
.long 0 // SizeOfStackReserve
.long 0 // SizeOfStackCommit
.long 0 // SizeOfHeapReserve
.long 0 // SizeOfHeapCommit
.long 0 // LoaderFlags
.long 0x6 // NumberOfRvaAndSizes
.quad 0 // ExportTable
.quad 0 // ImportTable
.quad 0 // ResourceTable
.quad 0 // ExceptionTable
.quad 0 // CertificationTable
.quad 0 // BaseRelocationTable
// Section table
section_table:
/*
* The EFI application loader requires a relocation section
* because EFI applications must be relocatable. This is a
* dummy section as far as we are concerned.
*/
.ascii ".reloc"
.byte 0
.byte 0 // end of 0 padding of section name
.long 0
.long 0
.long 0 // SizeOfRawData
.long 0 // PointerToRawData
.long 0 // PointerToRelocations
.long 0 // PointerToLineNumbers
.short 0 // NumberOfRelocations
.short 0 // NumberOfLineNumbers
.long 0x42100040 // Characteristics (section flags)
.ascii ".text"
.byte 0
.byte 0
.byte 0 // end of 0 padding of section name
.long _edata - _start // VirtualSize
.long _start - ImageBase // VirtualAddress
.long _edata - _start // SizeOfRawData
.long _start - ImageBase // PointerToRawData
.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)
_start:
stmfd sp!, {r0-r2, lr}
mov r2, r0
mov r3, r1
adr r1, .L_DYNAMIC
ldr r0, [r1]
add r1, r0, r1
adr r0, ImageBase
bl _relocate
teq r0, #0
bne 0f
ldmfd sp, {r0-r1}
bl efi_main
0: add sp, sp, #12
ldr pc, [sp], #4
.L_DYNAMIC:
.word _DYNAMIC - .