user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/options/rtld/x86/elf.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <elf.h>
+
+#define ELF_CLASS ELFCLASS32
+#define ELF_MACHINE EM_386
+
+using elf_ehdr = Elf32_Ehdr;
+using elf_phdr = Elf32_Phdr;
+using elf_dyn = Elf32_Dyn;
+using elf_rel = Elf32_Rel;
+using elf_rela = Elf32_Rela;
+using elf_relr = Elf32_Relr;
+using elf_sym = Elf32_Sym;
+using elf_addr = Elf32_Addr;
+
+using elf_info = Elf32_Word;
+using elf_addend = Elf32_Sword;
+
+using elf_version = Elf32_Half;
+using elf_verdef = Elf32_Verdef;
+using elf_verdaux = Elf32_Verdaux;
+using elf_verneed = Elf32_Verneed;
+using elf_vernaux = Elf32_Vernaux;
+
+#define ELF_R_SYM ELF32_R_SYM
+#define ELF_R_TYPE ELF32_R_TYPE
+#define ELF_ST_BIND ELF32_ST_BIND
+#define ELF_ST_TYPE ELF32_ST_TYPE
+
+#define R_NONE R_386_NONE
+#define R_JUMP_SLOT R_386_JMP_SLOT
+#define R_ABSOLUTE R_386_32
+#define R_GLOB_DAT R_386_GLOB_DAT
+#define R_RELATIVE R_386_RELATIVE
+#define R_IRELATIVE R_386_IRELATIVE
+#define R_OFFSET R_386_PC32
+#define R_COPY R_386_COPY
+#define R_TLS_DTPMOD R_386_TLS_DTPMOD32
+#define R_TLS_DTPREL R_386_TLS_DTPOFF32
+#define R_TLS_TPREL R_386_TLS_TPOFF
+#define R_TLSDESC R_386_TLS_DESC
+
+#define TP_TCB_OFFSET 0
+
+using ifunc_handler = elf_addr (*)(void);

user/include/mlibc/options/rtld/x86/entry.S

@@ -0,0 +1,13 @@
+#include "mlibc-asm/helpers.h"
+
+PROC_START(_start)
+.cfi_undefined eip
+	call relocateSelf
+
+	push %esp
+	call interpreterMain
+
+	jmp *%eax
+PROC_END(_start)
+
+GNU_STACK_NOTE()

user/include/mlibc/options/rtld/x86/runtime.S

@@ -0,0 +1,9 @@
+.global pltRelocateStub
+# save / restore all registers that can hold function parameters
+pltRelocateStub:
+	# we need to save / restore all registers than can hold function arguments
+	# we do not need to save callee-saved registers as they will not be trashed by lazyRelocate
+	# TODO: save floating point argument registers
+	ud2
+
+.section .note.GNU-stack,"",%progbits