diff options
Diffstat (limited to 'src/stem/linker')
-rw-r--r-- | src/stem/linker/elf.c | 31 | ||||
-rw-r--r-- | src/stem/linker/elf.h | 63 |
2 files changed, 94 insertions, 0 deletions
diff --git a/src/stem/linker/elf.c b/src/stem/linker/elf.c new file mode 100644 index 0000000..62030ee --- /dev/null +++ b/src/stem/linker/elf.c @@ -0,0 +1,31 @@ +#include "elf.h" +#include <mem/paging.h> +#include <mem/seg.h> +#include <stdlib.h> + +int elf_check(uint8_t *data) { + struct elf_ehdr *h = (struct elf_ehdr*)data; + if (h->e_ident[0] == 0x7F && h->e_ident[1] == 'E' && h->e_ident[2] == 'L' && h->e_ident[3] == 'F') return 0; + return 1; +} + +thread_entry elf_load(uint8_t *data, struct process* process) { + struct elf_ehdr *ehdr = (struct elf_ehdr*)data; + struct elf_phdr *phdr; + int i; + if (elf_check(data)) return 0; + + pagedir_switch(process->pagedir); + + phdr = (struct elf_phdr*)((uint8_t*)(data + ehdr->e_phoff)); + for (i = 0; i < ehdr->e_phnum; i++) { + if (phdr[i].p_type == PT_LOAD) { + seg_map(simpleseg_make(phdr[i].p_vaddr, phdr[i].p_memsz, (phdr[i].p_flags & PF_W) != 0), process->pagedir); + memcpy((uint8_t*)phdr[i].p_vaddr, data + phdr[i].p_offset, phdr[i].p_filesz); + if (phdr[i].p_memsz > phdr[i].p_filesz) { + memset((uint8_t*)phdr[i].p_vaddr + phdr[i].p_memsz, 0, phdr[i].p_memsz - phdr[i].p_filesz); + } + } + } + return (thread_entry)ehdr->e_entry; +} diff --git a/src/stem/linker/elf.h b/src/stem/linker/elf.h new file mode 100644 index 0000000..f84bb62 --- /dev/null +++ b/src/stem/linker/elf.h @@ -0,0 +1,63 @@ +#ifndef DEF_ELF_H +#define DEF_ELF_H + +#include <types.h> +#include <task/task.h> + +/* elf_phdr_t :: p_type : program header entries types */ +#define PT_NULL 0 +#define PT_LOAD 1 +#define PT_DYNAMIC 2 +#define PT_INTERP 3 +#define PT_NOTE 4 +#define PT_SHLIB 5 +#define PT_PHDR 6 +#define PT_LOPROC 0x70000000 +#define PT_HIPROC 0x7fffffff + +/* elf_phdr_t :: p_flags : program header entries flags */ +#define PF_X (1 << 0) +#define PF_W (1 << 1) +#define PF_R (1 << 2) + +struct elf_ehdr { + uint8_t e_ident[16]; /* ELF identification */ + uint16_t e_type; /* 2 (exec file) */ + uint16_t e_machine; /* 3 (intel architecture) */ + uint32_t e_version; /* 1 */ + uint32_t e_entry; /* starting point */ + uint32_t e_phoff; /* program header table offset */ + uint32_t e_shoff; /* section header table offset */ + uint32_t e_flags; /* various flags */ + uint16_t e_ehsize; /* ELF header (this) size */ + + uint16_t e_phentsize; /* program header table entry size */ + uint16_t e_phnum; /* number of entries */ + + uint16_t e_shentsize; /* section header table entry size */ + uint16_t e_shnum; /* number of entries */ + + uint16_t e_shstrndx; /* index of the section name string table */ +}; + +struct elf_phdr { + uint32_t p_type; /* type of segment */ + uint32_t p_offset; + uint32_t p_vaddr; + uint32_t p_paddr; + uint32_t p_filesz; + uint32_t p_memsz; + uint32_t p_flags; + uint32_t p_align; +}; + +struct phdr { + struct elf_phdr h; + uint8_t* data; +}; + +int elf_check(uint8_t *data); //0 if ok, 1 if not a valid ELF +thread_entry elf_load(uint8_t *data, struct process* process); //Load an ELF to a process, return entry point +struct process* elf_exec(uint8_t *data); //Creates a new process and a thread for running ELF file + +#endif |