WIP: Add a C Library, let's try to compile a Hosted GCC cross-compiler using this!

.gitignore

@@ -7,3 +7,5 @@ kernel/bin/moon.elf
 initrd/sys/moon.sym
 initrd/bin/**
 apps/bin/**
+base/usr/include/**
+base/usr/lib/**

Makefile

@@ -1,12 +1,13 @@
-build: $(LUNA_ROOT)/kernel/bin/moon.elf apps-build
+build: $(LUNA_ROOT)/kernel/bin/moon.elf apps-build libc-build
 
-clean: moon-clean initrd-clean apps-clean
+clean: moon-clean initrd-clean apps-clean libc-clean
 
 initrd-clean:
 	rm -f $(LUNA_ROOT)/initrd/boot/moon.elf $(LUNA_ROOT)/Luna.iso
 	rm -rf $(LUNA_ROOT)/initrd/bin
 
-install: $(LUNA_ROOT)/initrd/boot/moon.elf apps-install
+install: $(LUNA_ROOT)/initrd/boot/moon.elf apps-install libc-install
 
 include kernel/Makefile
 include apps/Makefile
+include libs/libc/Makefile

libs/libc/Makefile

@@ -0,0 +1,76 @@
+LIBC_DIR := $(LUNA_ROOT)/libs/libc
+LIBC_SRC := $(LIBC_DIR)/src
+LIBC_OBJ := $(LIBC_DIR)/lib
+LIBC_BIN := $(LIBC_DIR)/bin
+
+LIBC_CC := x86_64-elf-gcc
+LIBC_CXX := x86_64-elf-g++
+LIBC_NASM := nasm
+LIBC_AR := x86_64-elf-ar
+
+LIBC_CFLAGS := -Wall -Wextra -Werror -Os -ffreestanding -nostdlib -fno-omit-frame-pointer -mno-mmx -mno-sse -mno-sse2 -I$(LIBC_DIR)/include -isystem $(LIBC_DIR)/include
+LIBC_CXXFLAGS := -fno-rtti -fno-exceptions
+LIBC_NASMFLAGS := -felf64
+
+rwildcard=$(foreach d,$(wildcard $(1:=/*)),$(call rwildcard,$d,$2) $(filter $(subst *,%,$2),$d))
+
+LIBC_CXX_SRC = $(call rwildcard,$(LIBC_SRC),*.cpp)
+LIBC_C_SRC = $(call rwildcard,$(LIBC_SRC),*.c)
+LIBC_NASM_SRC = $(call rwildcard,$(LIBC_SRC),*.asm)
+
+LIBC_OBJS = $(patsubst $(LIBC_SRC)/%.cpp, $(LIBC_OBJ)/%.cpp.o, $(LIBC_CXX_SRC))
+LIBC_OBJS += $(patsubst $(LIBC_SRC)/%.c, $(LIBC_OBJ)/%.c.o, $(LIBC_C_SRC))
+LIBC_OBJS += $(patsubst $(LIBC_SRC)/%.asm, $(LIBC_OBJ)/%.asm.o, $(LIBC_NASM_SRC))
+
+$(LIBC_OBJ)/%.cpp.o: $(LIBC_SRC)/%.cpp
+	@mkdir -p $(@D)
+	$(LIBC_CXX) $(LIBC_CFLAGS) $(LIBC_CXXFLAGS) -o $@ -c $^
+
+$(LIBC_OBJ)/%.c.o: $(LIBC_SRC)/%.c
+	@mkdir -p $(@D)
+	$(LIBC_CC) $(LIBC_CFLAGS) -o $@ -c $^
+
+$(LIBC_OBJ)/%.asm.o: $(LIBC_SRC)/%.asm
+	@mkdir -p $(@D)
+	$(LIBC_NASM) $(LIBC_NASMFLAGS) -o $@ $^
+
+$(LIBC_BIN)/libc.a: $(LIBC_OBJS)
+	@mkdir -p $(@D)
+	$(LIBC_AR) rcs $@ $(LIBC_OBJS)
+
+$(LIBC_BIN)/crt0.o: $(LIBC_DIR)/crt0.asm
+	@mkdir -p $(@D)
+	$(LIBC_NASM) $(LIBC_NASMFLAGS) -o $@ $^
+
+$(LIBC_BIN)/crti.o: $(LIBC_DIR)/crti.asm
+	@mkdir -p $(@D)
+	$(LIBC_NASM) $(LIBC_NASMFLAGS) -o $@ $^
+
+$(LIBC_BIN)/crtn.o: $(LIBC_DIR)/crtn.asm
+	@mkdir -p $(@D)
+	$(LIBC_NASM) $(LIBC_NASMFLAGS) -o $@ $^
+
+libc-build: $(LIBC_BIN)/crt0.o $(LIBC_BIN)/crti.o $(LIBC_BIN)/crtn.o $(LIBC_BIN)/libc.a
+
+$(LUNA_ROOT)/base/usr/lib/libc.a: $(LIBC_BIN)/libc.a
+	@mkdir -p $(@D)
+	cp $^ $@
+
+$(LUNA_ROOT)/base/usr/lib/crt0.o: $(LIBC_BIN)/crt0.o
+	@mkdir -p $(@D)
+	cp $^ $@
+
+$(LUNA_ROOT)/base/usr/lib/crti.o: $(LIBC_BIN)/crti.o
+	@mkdir -p $(@D)
+	cp $^ $@
+
+$(LUNA_ROOT)/base/usr/lib/crtn.o: $(LIBC_BIN)/crtn.o
+	@mkdir -p $(@D)
+	cp $^ $@
+
+libc-install: $(LUNA_ROOT)/base/usr/lib/libc.a $(LUNA_ROOT)/base/usr/lib/crt0.o $(LUNA_ROOT)/base/usr/lib/crti.o $(LUNA_ROOT)/base/usr/lib/crtn.o
+
+libc-clean:
+	rm -rf $(LIBC_OBJ)/*
+	rm -rf $(LIBC_BIN)/*
+	rm -f $(LUNA_ROOT)/base/usr/lib/libc.a

libs/libc/crt0.asm

@@ -0,0 +1,29 @@
+section .text
+
+extern _init
+extern main
+extern _fini
+extern exit
+
+global _start
+_start:
+	; Set up end of the stack frame linked list.
+	xor rbp, rbp
+	push rbp ; rip=0
+	push rbp ; rbp=0
+	mov rbp, rsp
+
+	call _init
+
+    mov rdi, 0 ; argc = 0
+    mov rsi, 0 ; argv = 0
+
+	call main
+
+    push rax
+
+    call _fini
+
+    pop rdi
+
+	call exit

libs/libc/crti.asm

@@ -0,0 +1,11 @@
+section .init
+global _init
+_init:
+    push rbp
+    mov rbp, rsp
+
+section .fini
+global _fini
+_fini:
+    push rbp
+    mov rbp, rsp

libs/libc/crtn.asm

@@ -0,0 +1,7 @@
+section .init
+    pop rbp
+    ret
+
+section .fini
+    pop rbp
+    ret

libs/libc/include/luna/syscall.h

@@ -0,0 +1,17 @@
+#ifndef _SYSCALL_H
+#define _SYSCALL_H
+
+#define SYS_exit 0
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    void __syscall0(int sys_num);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libs/libc/include/stdio.h

@@ -0,0 +1,36 @@
+#ifndef _STDIO_H
+#define _STDIO_H
+
+#include <stdarg.h>
+#include <stddef.h>
+
+#define SEEK_SET 0
+
+typedef struct
+{
+    int unused;
+} FILE;
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    extern FILE* stderr;
+#define stderr stderr
+    int fclose(FILE*);
+    int fflush(FILE*);
+    FILE* fopen(const char*, const char*);
+    int fprintf(FILE*, const char*, ...);
+    size_t fread(void*, size_t, size_t, FILE*);
+    int fseek(FILE*, long, int);
+    long ftell(FILE*);
+    size_t fwrite(const void*, size_t, size_t, FILE*);
+    void setbuf(FILE*, char*);
+    int vfprintf(FILE*, const char*, va_list);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libs/libc/include/stdlib.h

@@ -0,0 +1,25 @@
+#ifndef _STDLIB_H
+#define _STDLIB_H
+
+#include <stddef.h>
+
+#define noreturn __attribute__((noreturn))
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    noreturn void abort();
+    noreturn void exit(int);
+    int atexit(void (*)(void));
+    int atoi(const char*);
+    void free(void*);
+    char* getenv(const char*);
+    void* malloc(size_t);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libs/libc/include/string.h

@@ -0,0 +1,23 @@
+#ifndef _STRING_H
+#define _STRING_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    void* memcpy(void*, const void*, size_t);
+    void* memset(void*, int, size_t);
+    char* strcpy(char*, const char*);
+    size_t strlen(const char*);
+    char* strcpy(char*, const char*);
+    char* strchr(const char*, int);
+    char* strcat(char*, const char*);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libs/libc/include/sys/types.h

@@ -0,0 +1,4 @@
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+typedef long int pid_t;
+#endif

libs/libc/include/unistd.h

@@ -0,0 +1,15 @@
+#ifndef _UNISTD_H
+#define _UNISTD_H
+#include <sys/types.h>
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+    int execv(const char*, char* const[]);
+    int execve(const char*, char* const[], char* const[]);
+    int execvp(const char*, char* const[]);
+    pid_t fork(void);
+#ifdef __cplusplus
+}
+#endif
+#endif

libs/libc/src/luna/syscall.cpp

@@ -0,0 +1,10 @@
+#include <luna/syscall.h>
+#include <stdint.h>
+
+extern "C"
+{
+    void __syscall0(int sys_num)
+    {
+        asm volatile("int $0x42" : : "a"(sys_num));
+    }
+}

libs/libc/src/stdio.cpp

@@ -0,0 +1,45 @@
+#include <stdio.h>
+
+extern "C"
+{
+    int fclose(FILE*)
+    {
+        return -1;
+    }
+    int fflush(FILE*)
+    {
+        return -1;
+    }
+    FILE* fopen(const char*, const char*)
+    {
+        return 0;
+    }
+    int fprintf(FILE*, const char*, ...)
+    {
+        return -1;
+    }
+    size_t fread(void*, size_t, size_t, FILE*)
+    {
+        return 0;
+    }
+    int fseek(FILE*, long, int)
+    {
+        return -1;
+    }
+    long ftell(FILE*)
+    {
+        return -1;
+    }
+    size_t fwrite(const void*, size_t, size_t, FILE*)
+    {
+        return 0;
+    }
+    void setbuf(FILE*, char*)
+    {
+        return;
+    }
+    int vfprintf(FILE*, const char*, va_list)
+    {
+        return -1;
+    }
+}

libs/libc/src/stdlib.cpp

@@ -0,0 +1,40 @@
+#include <luna/syscall.h>
+#include <stdlib.h>
+
+#define maybe_unused __attribute__((maybe_unused))
+#define unused __attribute__((unused))
+
+extern "C"
+{
+    noreturn void abort()
+    {
+        exit(-1);
+    }
+
+    noreturn void exit(int)
+    {
+        __syscall0(SYS_exit);
+        __builtin_unreachable();
+    }
+
+    int atexit(void (*)(void))
+    {
+        return -1;
+    }
+    int atoi(const char*)
+    {
+        return 0;
+    }
+    void free(void*)
+    {
+        return;
+    }
+    char* getenv(const char*)
+    {
+        return 0;
+    }
+    void* malloc(size_t)
+    {
+        return 0;
+    }
+}

libs/libc/src/string.cpp

@@ -0,0 +1,47 @@
+#include <string.h>
+
+extern "C"
+{
+    void* memcpy(void* dest, const void* src, size_t n)
+    {
+        for (size_t i = 0; i < n; ++i) { *((char*)dest + i) = *((char*)src + i); }
+        return dest;
+    }
+
+    void* memset(void* dest, int c, size_t n)
+    {
+        for (size_t i = 0; i < n; ++i) { *((char*)dest + i) = (char)c; }
+        return dest;
+    }
+
+    size_t strlen(const char* s)
+    {
+        const char* i = s;
+        for (; *i; ++i)
+            ;
+        return (i - s);
+    }
+
+    char* strcpy(char* dest, const char* src)
+    {
+        memcpy(dest, src, strlen(src) + 1);
+        return dest;
+    }
+
+    char* strcat(char* dest, const char* src)
+    {
+        size_t dest_len = strlen(dest);
+        size_t i;
+
+        for (i = 0; *(src + i); i++) *(char*)(dest + dest_len + i) = *(char*)(src + i);
+
+        *(char*)(dest + dest_len + i) = '\0';
+
+        return dest;
+    }
+
+    char* strchr(const char*, int)
+    {
+        return 0;
+    }
+}

libs/libc/src/unistd.cpp

@@ -0,0 +1,21 @@
+#include <unistd.h>
+
+extern "C"
+{
+    int execv(const char*, char* const[])
+    {
+        return -1;
+    }
+    int execve(const char*, char* const[], char* const[])
+    {
+        return -1;
+    }
+    int execvp(const char*, char* const[])
+    {
+        return -1;
+    }
+    pid_t fork(void)
+    {
+        return -1;
+    }
+}

tools/install-headers.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+set -e
+source $(dirname $0)/env.sh
+
+cd $LUNA_ROOT
+
+mkdir -p base
+mkdir -p base/usr/include
+mkdir -p base/usr/include/moon
+
+cp -RT libs/libc/include base/usr/include
+cp -RT kernel/include base/usr/include/moon