refactor: decouple the executable file implementations with execve functionality.

[lunaix-os.git] / lunaix-os / includes / lunaix / exebi / elf32.h

diff --git a/lunaix-os/includes/lunaix/exebi/elf32.h b/lunaix-os/includes/lunaix/exebi/elf32.h
new file mode 100644 (file)
index 0000000..d9f4f58
--- /dev/null
+++ b/lunaix-os/includes/lunaix/exebi/elf32.h
@@ -0,0 +1,123 @@
+#ifndef __LUNAIX_ELF32_H
+#define __LUNAIX_ELF32_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 PT_INTERP 3
+
+#define PF_X 0x1
+#define PF_W 0x2
+#define PF_R 0x4
+
+#define EM_NONE 0
+#define EM_386 3
+
+#define EV_CURRENT 1
+
+// [0x7f, 'E', 'L', 'F']
+#define ELFMAGIC 0x464c457fU
+#define ELFCLASS32 1
+#define ELFCLASS64 2
+#define ELFDATA2LSB 1
+#define ELFDATA2MSB 2
+
+#define EI_CLASS 4
+#define EI_DATA 5
+
+#define NO_LOADER 0
+#define DEFAULT_LOADER "usr/ld"
+
+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;
+};
+
+struct elf32
+{
+    void* elf_file;
+    struct elf32_ehdr eheader;
+    struct elf32_phdr* pheaders;
+};
+
+#define declare_elf32(elf, elf_vfile)                                          \
+    struct elf32 elf = { .elf_file = elf_vfile, .pheaders = (void*)0 }
+
+int
+elf32_open(struct elf32* elf, const char* path);
+
+int
+elf32_openat(struct elf32* elf, void* elf_vfile);
+
+int
+elf32_static_linked(const struct elf32* elf);
+
+int
+elf32_close(struct elf32* elf);
+
+/**
+ * @brief Try to find the PT_INTERP section. If found, copy it's content to
+ * path_out
+ *
+ * @param elf Opened elf32 descriptor
+ * @param path_out
+ * @param len size of path_out buffer
+ * @return int
+ */
+int
+elf32_find_loader(const struct elf32* elf, char* path_out, size_t len);
+
+int
+elf32_read_ehdr(struct elf32* elf);
+
+int
+elf32_read_phdr(struct elf32* elf);
+
+/**
+ * @brief Estimate how much memeory will be acquired if we load all loadable
+ * sections.、
+ *
+ * @param elf
+ * @return size_t
+ */
+size_t
+elf32_loadable_memsz(const struct elf32* elf);
+
+#define SIZE_EHDR sizeof(struct elf32_ehdr)
+#define SIZE_PHDR sizeof(struct elf32_phdr)
+
+#endif /* __LUNAIX_ELF32_H */