feat: basic elf32 loader (only LOAD segment is supported)

[lunaix-os.git] / lunaix-os / includes / lunaix / elf.h

diff --git a/lunaix-os/includes/lunaix/elf.h b/lunaix-os/includes/lunaix/elf.h
new file mode 100644 (file)
index 0000000..ec4196b
--- /dev/null
+++ b/lunaix-os/includes/lunaix/elf.h
@@ -0,0 +1,75 @@
+#ifndef __LUNAIX_ELF_H
+#define __LUNAIX_ELF_H
+
+#include <lunaix/types.h>
+
+typedef unsigned int elf32_ptr_t;
+typedef unsigned short elf32_hlf_t;
+typedef unsigned int elf32_off_t;
+typedef unsigned int elf32_swd_t;
+typedef unsigned int elf32_wrd_t;
+
+#define ET_NONE 0
+#define ET_EXEC 2
+
+#define PT_LOAD 1
+
+#define PF_X 0x1
+#define PF_W 0x2
+#define PF_R 0x4
+
+#define EM_NONE 0
+#define EM_386 3
+
+#define EV_CURRENT 1
+
+#define ELFMAGIC 0x464c457fU
+#define ELFCLASS32 1
+#define ELFCLASS64 2
+#define ELFDATA2LSB 1
+#define ELFDATA2MSB 2
+
+#define EI_CLASS 4
+#define EI_DATA 5
+
+struct elf32_ehdr
+{
+    u8_t e_ident[16];
+    elf32_hlf_t e_type;
+    elf32_hlf_t e_machine;
+    elf32_wrd_t e_version;
+    elf32_ptr_t e_entry;
+    elf32_off_t e_phoff;
+    elf32_off_t e_shoff;
+    elf32_wrd_t e_flags;
+    elf32_hlf_t e_ehsize;
+    elf32_hlf_t e_phentsize;
+    elf32_hlf_t e_phnum;
+    elf32_hlf_t e_shentsize;
+    elf32_hlf_t e_shnum;
+    elf32_hlf_t e_shstrndx;
+};
+
+struct elf32_phdr
+{
+    elf32_wrd_t p_type;
+    elf32_off_t p_offset;
+    elf32_ptr_t p_va;
+    elf32_ptr_t p_pa;
+    elf32_wrd_t p_filesz;
+    elf32_wrd_t p_memsz;
+    elf32_wrd_t p_flags;
+    elf32_wrd_t p_align;
+};
+
+#define SIZE_EHDR sizeof(struct elf32_ehdr)
+#define SIZE_PHDR sizeof(struct elf32_phdr)
+
+static inline int
+elf_check_exec(struct elf32_ehdr* ehdr)
+{
+    return (*(u32_t*)(ehdr->e_ident) == ELFMAGIC) ||
+           ehdr->e_ident[EI_CLASS] == ELFCLASS32 ||
+           ehdr->e_ident[EI_DATA] == ELFDATA2LSB || ehdr->e_type == ET_EXEC;
+}
+#endif /* __LUNAIX_ELF_H */