user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/options/rtld/x86_64/elf.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include <elf.h>
+
+#define ELF_CLASS ELFCLASS64
+#define ELF_MACHINE EM_X86_64
+
+using elf_ehdr = Elf64_Ehdr;
+using elf_phdr = Elf64_Phdr;
+using elf_dyn = Elf64_Dyn;
+using elf_rel = Elf64_Rel;
+using elf_rela = Elf64_Rela;
+using elf_relr = Elf64_Relr;
+using elf_sym = Elf64_Sym;
+using elf_addr = Elf64_Addr;
+
+using elf_info = Elf64_Xword;
+using elf_addend = Elf64_Sxword;
+
+using elf_version = Elf64_Half;
+using elf_verdef = Elf64_Verdef;
+using elf_verdaux = Elf64_Verdaux;
+using elf_verneed = Elf64_Verneed;
+using elf_vernaux = Elf64_Vernaux;
+
+#define ELF_R_SYM ELF64_R_SYM
+#define ELF_R_TYPE ELF64_R_TYPE
+#define ELF_ST_BIND ELF64_ST_BIND
+#define ELF_ST_TYPE ELF64_ST_TYPE
+
+#define R_NONE R_X86_64_NONE
+#define R_JUMP_SLOT R_X86_64_JUMP_SLOT
+#define R_ABSOLUTE R_X86_64_64
+#define R_GLOB_DAT R_X86_64_GLOB_DAT
+#define R_RELATIVE R_X86_64_RELATIVE
+#define R_IRELATIVE R_X86_64_IRELATIVE
+// #define R_OFFSET
+#define R_COPY R_X86_64_COPY
+#define R_TLS_DTPMOD R_X86_64_DTPMOD64
+#define R_TLS_DTPREL R_X86_64_DTPOFF64
+#define R_TLS_TPREL R_X86_64_TPOFF64
+#define R_TLSDESC R_X86_64_TLSDESC
+
+#define TP_TCB_OFFSET 0
+
+using ifunc_handler = elf_addr (*)(void);

user/include/mlibc/options/rtld/x86_64/entry.S

@@ -0,0 +1,14 @@
+#include "mlibc-asm/helpers.h"
+
+PROC_START(_start)
+.cfi_undefined rip
+	call relocateSelf
+
+	mov %rsp, %rdi
+	call interpreterMain
+
+	jmp *%rax
+PROC_END(_start)
+
+GNU_STACK_NOTE()
+

user/include/mlibc/options/rtld/x86_64/runtime.S

@@ -0,0 +1,63 @@
+.global __mlibcTlsdescStatic
+.hidden __mlibcTlsdescStatic
+.type __mlibcTlsdescStatic, @function
+__mlibcTlsdescStatic:
+	mov 8(%rax), %rax
+	ret
+
+.global __mlibcTlsdescDynamic
+.hidden __mlibcTlsdescDynamic
+.type __mlibcTlsdescDynamic, @function
+__mlibcTlsdescDynamic:
+	push %rbx
+	push %rcx
+
+	mov 8(%rax), %rax
+
+	mov (%rax), %rbx // index
+	mov 8(%rax), %rcx // addend
+
+	mov %fs:16, %rax // *tp->dtvPointers
+	mov (%rax, %rbx, 8), %rax // dtvPointers[0][index]
+	add %rcx, %rax // + addend
+	sub %fs:0, %rax
+
+	pop %rcx
+	pop %rbx
+	ret
+
+.global pltRelocateStub
+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
+
+	push %rsi
+	push %rdi
+	mov 16(%rsp), %rdi
+	mov 24(%rsp), %rsi
+
+	push %rax
+	push %rcx
+	push %rdx
+	push %r8
+	push %r9
+	push %r10
+
+	call lazyRelocate
+	mov %rax, %r11
+
+	pop %r10
+	pop %r9
+	pop %r8
+	pop %rdx
+	pop %rcx
+	pop %rax
+	
+	pop %rdi
+	pop %rsi
+	add $16, %rsp
+	jmp *%r11
+
+.section .note.GNU-stack,"",%progbits
+