diff --git a/arch/amd64/Limine.c b/arch/amd64/Limine.c index ea65c20..f36d43e 100644 --- a/arch/amd64/Limine.c +++ b/arch/amd64/Limine.c @@ -220,6 +220,7 @@ void init_limine() binfo.Kernel.PhysicalBase = (void *)KernelAddressResponse->physical_base; binfo.Kernel.VirtualBase = (void *)KernelAddressResponse->virtual_base; + binfo.Kernel.FileBase = KernelFileResponse->kernel_file->address; strcpy(binfo.Kernel.CommandLine, KernelFileResponse->kernel_file->cmdline); binfo.Kernel.Size = KernelFileResponse->kernel_file->size; trace("Kernel physical address: %p", KernelAddressResponse->physical_base); diff --git a/core/Symbols.cpp b/core/Symbols.cpp new file mode 100644 index 0000000..ef9bb18 --- /dev/null +++ b/core/Symbols.cpp @@ -0,0 +1,143 @@ +#include +#include +#include +#include + +// #pragma GCC diagnostic ignored "-Wignored-qualifiers" + +typedef struct +{ + unsigned char e_ident[16]; + uint16_t e_type; + uint16_t e_machine; + uint32_t e_version; + uint64_t e_entry; + uint64_t e_phoff; + uint64_t e_shoff; + uint32_t e_flags; + uint16_t e_ehsize; + uint16_t e_phentsize; + uint16_t e_phnum; + uint16_t e_shentsize; + uint16_t e_shnum; + uint16_t e_shstrndx; +} Elf64_Ehdr; + +typedef struct +{ + uint32_t sh_name; + uint32_t sh_type; + uint64_t sh_flags; + uint64_t sh_addr; + uint64_t sh_offset; + uint64_t sh_size; + uint32_t sh_link; + uint32_t sh_info; + uint64_t sh_addralign; + uint64_t sh_entsize; +} Elf64_Shdr; + +typedef struct +{ + uint32_t st_name; + unsigned char st_info; + unsigned char st_other; + uint16_t st_shndx; + uint64_t st_value; + uint64_t st_size; +} Elf64_Sym; + +#define SHT_SYMTAB 2 +#define SHT_STRTAB 3 + +namespace SymbolResolver +{ + Symbols::SymbolTable *SymTable = nullptr; + uint64_t TotalEntries = 0; + + Symbols::Symbols(uint64_t Address) + { + debug("Solving symbols for address: %#lx", Address); + Elf64_Ehdr *Header = (Elf64_Ehdr *)Address; + if (Header->e_ident[0] != 0x7F && + Header->e_ident[1] != 'E' && + Header->e_ident[2] != 'L' && + Header->e_ident[3] != 'F') + { + error("Invalid ELF header"); + return; + } + Elf64_Shdr *ElfSections = (Elf64_Shdr *)(Address + Header->e_shoff); + Elf64_Sym *ElfSymbols = nullptr; + char *strtab = nullptr; + + for (uint64_t i = 0; i < Header->e_shnum; i++) + switch (ElfSections[i].sh_type) + { + case SHT_SYMTAB: + ElfSymbols = (Elf64_Sym *)(Address + ElfSections[i].sh_offset); + TotalEntries = ElfSections[i].sh_size / sizeof(Elf64_Sym); + debug("Symbol table found, %d entries", TotalEntries); + break; + case SHT_STRTAB: + if (Header->e_shstrndx == i) + { + debug("String table found, %d entries", ElfSections[i].sh_size); + } + else + { + strtab = (char *)Address + ElfSections[i].sh_offset; + debug("String table found, %d entries", ElfSections[i].sh_size); + } + break; + } + + if (ElfSymbols != nullptr && strtab != nullptr) + { + size_t Index, MinimumIndex; + for (size_t i = 0; i < TotalEntries - 1; i++) + { + MinimumIndex = i; + for (Index = i + 1; Index < TotalEntries; Index++) + if (ElfSymbols[Index].st_value < ElfSymbols[MinimumIndex].st_value) + MinimumIndex = Index; + Elf64_Sym tmp = ElfSymbols[MinimumIndex]; + ElfSymbols[MinimumIndex] = ElfSymbols[i]; + ElfSymbols[i] = tmp; + } + + while (ElfSymbols[0].st_value == 0) + { + ElfSymbols++; + TotalEntries--; + } + + trace("Symbol table loaded, %d entries (%ldKB)", TotalEntries, TO_KB(TotalEntries * sizeof(SymbolTable))); + // TODO: broken? + // SymTable = new SymbolTable[TotalEntries]; + SymTable = (SymbolTable *)KernelAllocator.RequestPages((TotalEntries * sizeof(SymbolTable)) / PAGE_SIZE + 1); + // do_mem_test(); + + for (size_t i = 0, g = TotalEntries; i < g; i++) + { + SymTable[i].Address = ElfSymbols[i].st_value; + SymTable[i].FunctionName = &strtab[ElfSymbols[i].st_name]; + } + } + } + + Symbols::~Symbols() + { + // delete SymTable; + KernelAllocator.FreePages(SymTable, (TotalEntries * sizeof(SymbolTable)) / PAGE_SIZE + 1); + } + + const char *Symbols::GetSymbolFromAddress(uint64_t Address) + { + Symbols::SymbolTable Result{0, (char *)""}; + for (size_t i = 0; i < TotalEntries; i++) + if (SymTable[i].Address <= Address && SymTable[i].Address > Result.Address) + Result = SymTable[i]; + return Result.FunctionName; + } +} diff --git a/include/boot/binfo.h b/include/boot/binfo.h index ba6315f..50a3d1e 100644 --- a/include/boot/binfo.h +++ b/include/boot/binfo.h @@ -106,6 +106,7 @@ struct BootInfo { void *PhysicalBase; void *VirtualBase; + void *FileBase; char CommandLine[256]; uint64_t Size; } Kernel; diff --git a/include/symbols.hpp b/include/symbols.hpp new file mode 100644 index 0000000..bb203f7 --- /dev/null +++ b/include/symbols.hpp @@ -0,0 +1,21 @@ +#pragma once +#include + +namespace SymbolResolver +{ + class Symbols + { + public: + struct SymbolTable + { + uint64_t Address; + char *FunctionName; + }; + + Symbols(uint64_t Address); + ~Symbols(); + const char *GetSymbolFromAddress(uint64_t Address); + }; +} + +extern SymbolResolver::Symbols *SymTbl;