gnu-efi/gnuefi/crt0-efi-ia32-local.S
Callum Farmer e092a94869
Add non-objcopy IA32 crt0/lds
* Needed by embedded (MacOS) ELF toolchain

Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
2024-07-16 14:49:52 +01:00

177 lines
5.3 KiB
ArmAsm

.section .text.head
/*
* Magic "MZ" signature for PE/COFF
*/
.globl ImageBase
ImageBase:
.ascii "MZ"
.skip 58 // 'MZ' + pad + offset == 64
.4byte pe_header - ImageBase // Offset to the PE header.
pe_header:
.ascii "PE"
.2byte 0
coff_header:
.2byte 0x14c // i386+
.2byte 4 // nr_sections
.4byte 0 // TimeDateStamp
.4byte 0 // PointerToSymbolTable
.4byte 0 // NumberOfSymbols
.2byte section_table - optional_header // SizeOfOptionalHeader
.2byte 0x306 // Characteristics.
// IMAGE_FILE_32BIT_MACHINE |
// IMAGE_FILE_DEBUG_STRIPPED |
// IMAGE_FILE_EXECUTABLE_IMAGE |
// IMAGE_FILE_LINE_NUMS_STRIPPED
optional_header:
.2byte 0x10b // PE32+ format
.byte 0x02 // MajorLinkerVersion
.byte 0x14 // MinorLinkerVersion
.4byte _etext - _start // SizeOfCode
.4byte _alldata_size - ImageBase // SizeOfInitializedData
.4byte 0 // SizeOfUninitializedData
.4byte _start - ImageBase // AddressOfEntryPoint
.4byte _start - ImageBase // BaseOfCode
.4byte _reloc - ImageBase // BaseOfData
extra_header_fields:
.4byte 0 // ImageBase
.4byte 0x1000 // SectionAlignment
.4byte 0x1000 // FileAlignment
.2byte 0 // MajorOperatingSystemVersion
.2byte 0 // MinorOperatingSystemVersion
.2byte 0 // MajorImageVersion
.2byte 0 // MinorImageVersion
.2byte 0 // MajorSubsystemVersion
.2byte 0 // MinorSubsystemVersion
.4byte 0 // Win32VersionValue
.4byte _image_end - ImageBase // SizeOfImage
// Everything before the kernel image is considered part of the header
.4byte _start - ImageBase // SizeOfHeaders
.4byte 0 // CheckSum
.2byte EFI_SUBSYSTEM // Subsystem
.2byte 0 // DllCharacteristics
.4byte 0 // SizeOfStackReserve
.4byte 0 // SizeOfStackCommit
.4byte 0 // SizeOfHeapReserve
.4byte 0 // SizeOfHeapCommit
.4byte 0 // LoaderFlags
.4byte 0x10 // NumberOfRvaAndSizes
.8byte 0 // ExportTable
.8byte 0 // ImportTable
.8byte 0 // ResourceTable
.8byte 0 // ExceptionTable
.8byte 0 // CertificationTable
.4byte _reloc - ImageBase // BaseRelocationTable (VirtualAddress)
.4byte _reloc_vsize - ImageBase // BaseRelocationTable (Size)
.8byte 0 // Debug
.8byte 0 // Architecture
.8byte 0 // Global Ptr
.8byte 0 // TLS Table
.8byte 0 // Load Config Table
.8byte 0 // Bound Import
.8byte 0 // IAT
.8byte 0 // Delay Import Descriptor
.8byte 0 // CLR Runtime Header
.8byte 0 // Reserved, must be zero
// Section table
section_table:
.ascii ".text\0\0\0"
.4byte _evtext - _start // VirtualSize
.4byte _start - ImageBase // VirtualAddress
.4byte _etext - _start // SizeOfRawData
.4byte _start - ImageBase // PointerToRawData
.4byte 0 // PointerToRelocations (0 for executables)
.4byte 0 // PointerToLineNumbers (0 for executables)
.2byte 0 // NumberOfRelocations (0 for executables)
.2byte 0 // NumberOfLineNumbers (0 for executables)
.4byte 0x60000020 // Characteristics (section flags)
/*
* 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\0\0"
.4byte _reloc_vsize - ImageBase // VirtualSize
.4byte _reloc - ImageBase // VirtualAddress
.4byte _reloc_size - ImageBase // SizeOfRawData
.4byte _reloc - ImageBase // PointerToRawData
.4byte 0 // PointerToRelocations
.4byte 0 // PointerToLineNumbers
.2byte 0 // NumberOfRelocations
.2byte 0 // NumberOfLineNumbers
.4byte 0x42000040 // Characteristics (section flags)
.ascii ".data\0\0\0"
.4byte _data_vsize - ImageBase // VirtualSize
.4byte _data - ImageBase // VirtualAddress
.4byte _data_size - ImageBase // SizeOfRawData
.4byte _data - ImageBase // PointerToRawData
.4byte 0 // PointerToRelocations
.4byte 0 // PointerToLineNumbers
.2byte 0 // NumberOfRelocations
.2byte 0 // NumberOfLineNumbers
.4byte 0xC0000040 // Characteristics (section flags)
.ascii ".rodata\0"
.4byte _rodata_vsize - ImageBase // VirtualSize
.4byte _rodata - ImageBase // VirtualAddress
.4byte _rodata_size - ImageBase // SizeOfRawData
.4byte _rodata - ImageBase // PointerToRawData
.4byte 0 // PointerToRelocations
.4byte 0 // PointerToLineNumbers
.2byte 0 // NumberOfRelocations
.2byte 0 // NumberOfLineNumbers
.4byte 0x40000040 // Characteristics (section flags)
.globl _start
.type _start,%function
_start:
pushl %ebp
movl %esp,%ebp
pushl 12(%ebp) # copy "image" argument
pushl 8(%ebp) # copy "systab" argument
call 0f
0: popl %eax
movl %eax,%ebx
addl $ImageBase-0b,%eax # %eax = ldbase
addl $_DYNAMIC-0b,%ebx # %ebx = _DYNAMIC
pushl %ebx # pass _DYNAMIC as second argument
pushl %eax # pass ldbase as first argument
call _relocate
popl %ebx
popl %ebx
testl %eax,%eax
jne .exit
call _entry # call app with "image" and "systab" argument
.exit: leave
ret
// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
.data
dummy: .4byte 0
#define IMAGE_REL_ABSOLUTE 0
.section .reloc
.4byte dummy // Page RVA
.4byte 12 // Block Size (2*4+2*2), must be aligned by 32 Bits
.2byte (IMAGE_REL_ABSOLUTE<<12) + 0 // reloc for dummy
.2byte (IMAGE_REL_ABSOLUTE<<12) + 0 // reloc for dummy
#if defined(__ELF__) && defined(__linux__)
.section .note.GNU-stack,"",%progbits
#endif