From e092a948698f36ba506328000b1ee94ecf7a4cd4 Mon Sep 17 00:00:00 2001 From: Callum Farmer Date: Tue, 16 Jul 2024 11:37:27 +0100 Subject: [PATCH] Add non-objcopy IA32 crt0/lds * Needed by embedded (MacOS) ELF toolchain Signed-off-by: Callum Farmer --- gnuefi/Makefile | 4 +- gnuefi/crt0-efi-ia32-local.S | 176 ++++++++++++++++++++++++++++++++++ gnuefi/elf_ia32_efi_local.lds | 141 +++++++++++++++++++++++++++ 3 files changed, 319 insertions(+), 2 deletions(-) create mode 100644 gnuefi/crt0-efi-ia32-local.S create mode 100644 gnuefi/elf_ia32_efi_local.lds diff --git a/gnuefi/Makefile b/gnuefi/Makefile index c84b889..89da83a 100644 --- a/gnuefi/Makefile +++ b/gnuefi/Makefile @@ -80,7 +80,7 @@ endif # on aarch64, avoid jump tables before all relocations have been processed reloc_aarch64.o: CFLAGS += -fno-jump-tables -ifneq (,$(filter $(ARCH),aarch64 riscv64)) +ifneq (,$(filter $(ARCH),aarch64 riscv64 ia32)) CRT0_LOCAL_TARGET = crt0-efi-$(ARCH)-local.o endif @@ -116,7 +116,7 @@ ifneq (,$(findstring FreeBSD,$(OS))) ifeq ($(ARCH),x86_64) $(INSTALL) -m 644 $(SRCDIR)/elf_$(ARCH)_fbsd_efi.lds $(INSTALLROOT)$(LIBDIR) else - ifneq (,$(filter $(ARCH),aarch64 riscv64)) + ifneq (,$(filter $(ARCH),aarch64 riscv64 ia32)) $(INSTALL) -m 644 $(SRCDIR)/elf_$(ARCH)_efi_local.lds $(INSTALLROOT)$(LIBDIR) endif $(INSTALL) -m 644 $(SRCDIR)/elf_$(ARCH)_efi.lds $(INSTALLROOT)$(LIBDIR) diff --git a/gnuefi/crt0-efi-ia32-local.S b/gnuefi/crt0-efi-ia32-local.S new file mode 100644 index 0000000..8b562ab --- /dev/null +++ b/gnuefi/crt0-efi-ia32-local.S @@ -0,0 +1,176 @@ +.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 diff --git a/gnuefi/elf_ia32_efi_local.lds b/gnuefi/elf_ia32_efi_local.lds new file mode 100644 index 0000000..4e0b5f1 --- /dev/null +++ b/gnuefi/elf_ia32_efi_local.lds @@ -0,0 +1,141 @@ +OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(_start) +SECTIONS +{ + .text 0 : { + *(.text.head) + . = ALIGN(4096); + _text = .; + *(.text) + *(.text.*) + *(.gnu.linkonce.t.*) + *(.plt) + . = ALIGN(16); + _evtext = .; + . = ALIGN(4096); + _etext = .; + } =0 + _text_vsize = _evtext - _text; + _text_size = _etext - _text; + . = ALIGN(4096); + _reloc = .; + .reloc : { + *(.reloc) + _evreloc = .; + . = ALIGN(4096); + _ereloc = .; + } =0 + _reloc_vsize = _evreloc - _reloc; + _reloc_size = _ereloc - _reloc; + . = ALIGN(4096); + _data = .; + _DYNAMIC = .; + .dynamic : { *(.dynamic) } + . = ALIGN(4096); + .data : + { + *(.sdata) + *(.data) + *(.data1) + *(.data.*) + *(.got.plt) + *(.got) + + /* + * Note that these aren't the using the GNU "CONSTRUCTOR" output section + * command, so they don't start with a size. Because of p2align and the + * end/END definitions, and the fact that they're mergeable, they can also + * have NULLs which aren't guaranteed to be at the end. + */ + . = ALIGN(16); + __init_array_start = .; + *(SORT(.init_array.*)) + *(.init_array) + __init_array_end = .; + . = ALIGN(16); + __CTOR_LIST__ = .; + *(SORT(.ctors.*)) + *(.ctors) + __CTOR_END__ = .; + . = ALIGN(16); + __DTOR_LIST__ = .; + *(SORT(.dtors.*)) + *(.dtors) + __DTOR_END__ = .; + . = ALIGN(16); + __fini_array_start = .; + *(SORT(.fini_array.*)) + *(.fini_array) + __fini_array_end = .; + + /* the EFI loader doesn't seem to like a .bss section, so we stick + it all into .data: */ + . = ALIGN(16); + _bss = .; + *(.sbss) + *(.scommon) + *(.dynbss) + *(.bss) + *(.bss.*) + *(COMMON) + . = ALIGN(16); + _bss_end = .; + _evdata = .; + . = ALIGN(4096); + _edata = .; + } =0 + _data_vsize = _evdata - _data; + _data_size = _edata - _data; + + . = ALIGN(4096); + _rodata = .; + .rela : + { + *(.rela.text*) + *(.rela.data*) + *(.rela.got) + *(.rela.dyn) + *(.rela.stab) + *(.rela.init_array*) + *(.rela.fini_array*) + *(.rela.ctors*) + *(.rela.dtors*) + + } + . = ALIGN(4096); + .rela.plt : { *(.rela.plt) } + . = ALIGN(4096); + .rodata : { + *(.rodata*) + _evrodata = .; + . = ALIGN(4096); + _erodata = .; + } =0 + _rodata_vsize = _evrodata - _rodata; + _rodata_size = _erodata - _rodata; + _image_end = .; + _alldata_size = _image_end - _reloc; + + . = ALIGN(4096); + .dynsym : { *(.dynsym) } + . = ALIGN(4096); + .dynstr : { *(.dynstr) } + . = ALIGN(4096); + .note.gnu.build-id : { *(.note.gnu.build-id) } + . = ALIGN(4096); + .hash : { *(.hash) } + . = ALIGN(4096); + .gnu.hash : { *(.gnu.hash) } + . = ALIGN(4096); + .eh_frame : { *(.eh_frame) } + .eh_frame_hdr : { *(.eh_frame_hdr) } + . = ALIGN(4096); + .gcc_except_table : { *(.gcc_except_table*) } + /DISCARD/ : + { + *(.rela.reloc) + *(.note.GNU-stack) + } + .comment 0 : { *(.comment) } +} \ No newline at end of file