Started work on the full ELF loader and C++ support

kernel/sys/syscall.c

@@ -127,9 +127,14 @@ static int close(int fd) {
 
 static int sys_sbrk(int size) {
 	uintptr_t ret = current_process->image.heap;
-	current_process->image.heap += size;
+	uintptr_t i_ret = ret;
+	while (ret % 0x1000) {
+		ret++;
+	}
+	current_process->image.heap += (ret - i_ret) + size;
 	while (current_process->image.heap > current_process->image.heap_actual) {
 		current_process->image.heap_actual += 0x1000;
+		assert(current_process->image.heap_actual % 0x1000 == 0);
 		alloc_frame(get_page(current_process->image.heap_actual, 1, current_directory), 0, 1);
 	}
 	return ret;

userspace/Makefile

@@ -1,6 +1,8 @@
 CC = i686-pc-toaru-gcc
+CPP = i686-pc-toaru-g++
 CFLAGS = -march=core2 -std=c99 -O3 -m32 -Wa,--32
-EXECUTABLES = $(patsubst %.c,../hdd/bin/%,$(wildcard *.c))
+CPPFLAGS = -march=core2 -O3 -m32 -Wa,--32
+EXECUTABLES = $(patsubst %.c,../hdd/bin/%,$(wildcard *.c)) $(patsubst %.cpp,../hdd/bin/%,$(wildcard *.cpp))
 ERRORS = 2>>/tmp/.build-errors || util/mk-error
 
 
@@ -14,5 +16,11 @@ clean:
 ../hdd/bin/freetype_test: freetype_test.c
 	${CC} ${CFLAGS} -s -I ../util/toaru-toolchain/i686-pc-toaru/include/freetype2/ -o $@ $< ../util/toaru-toolchain/i686-pc-toaru/lib/libfreetype.a
 
+../hdd/bin/%: %.cpp
+	${CPP} ${CPPFLAGS} -s -o $@ $<
+
+../hdd/bin/ld: ld.c
+	${CC} ${CFLAGS} -s -fPIC -o $@ $<
+
 ../hdd/bin/%: %.c
 	${CC} ${CFLAGS} -s -o $@ $<

userspace/cpp_test.cpp

@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <queue>
+#include <string>
+#include <fstream>
+#include <iostream>
+
+class test {
+	private:
+		int i;
+	public:
+		test() {
+			i = 0;
+		}
+		void inc() {
+			i++;
+		}
+		int value() {
+			return i;
+		}
+};
+
+int main() {
+	std::cout << "Hello world\n";
+
+	int * x = (int *)malloc(sizeof(int));
+	printf("%p\n", x);
+	test * t = new test();
+	printf("%d\n", t->value());
+	t->inc();
+	printf("%d\n", t->value());
+
+	std::queue<int> q;
+	q.push(4);
+	q.push(20);
+	q.push(5);
+	q.push(19);
+
+	while (!q.empty()) {
+		printf("%d\n", q.front());
+		q.pop();
+	}
+
+	std::string s;
+
+	std::cin >> s;
+
+	printf("%d: %s\n", s.length(), s.c_str());
+
+
+	return 0;
+}

userspace/ld.c

@@ -30,6 +30,7 @@ uintptr_t DESTINATION = 0x03000000;
 int _main();
 int argc;
 char ** argv;
+uintptr_t epoint = 0;
 
 /**
  * Application entry point.
@@ -63,19 +64,21 @@ here:
 	size_t binary_size;      /**< Size of the file */
 	char * binary_buf;       /**< Buffer to store the binary in memory */
 	Elf32_Header * header;   /**< ELF header */
-	char * string_table[5];  /**< Room for some string tables */
+	char * string_table;     /**< Room for some string tables */
+	uintptr_t __init = 0;
 
 	/* Open the requested binary */
 	binary = fopen(argv[1], "r");
 
-	/* Hack because we don't have seek/tell */
-	char garbage[3];
-	binary_size = 0;
-	while (fread((void *)&garbage, 1, 1, binary) != 0) {
-		++binary_size;
+	if (!binary) {
+		printf("Oh no! This is terrible!\n");
+		return 1;
 	}
-	fclose(binary);
-	binary = fopen(argv[1], "r");
+
+	/* Hack because we don't have seek/tell */
+	fseek(binary, 0, SEEK_END);
+	binary_size = ftell(binary);
+	fseek(binary, 0, SEEK_SET);
 
 	/* Read the binary into a buffer */
 	binary_buf = malloc(binary_size);
@@ -89,6 +92,21 @@ here:
 			header->e_ident[1] != ELFMAG1 ||
 			header->e_ident[2] != ELFMAG2 ||
 			header->e_ident[3] != ELFMAG3) {
+		printf("Failed to load binary: bad magic\n");
+		return 1;
+	}
+
+	uint32_t i = 0;
+	for (uint32_t x = 0; x < header->e_shentsize * header->e_shnum; x += header->e_shentsize) {
+		Elf32_Shdr * shdr = (Elf32_Shdr *)((uintptr_t)header + (header->e_shoff + x));
+		if (i == header->e_shstrndx) {
+			string_table = (char *)((uintptr_t)header + shdr->sh_offset);
+		}
+		++i;
+	}
+
+	if (!string_table) {
+		printf("No string table?\n");
 		return 1;
 	}
 
@@ -100,18 +118,37 @@ here:
 		Elf32_Shdr * shdr = (Elf32_Shdr *)((uintptr_t)binary_buf + (header->e_shoff + x));
 
 		if (shdr->sh_addr) {
-			memcpy((void *)shdr->sh_addr,(void *)((uintptr_t)header + shdr->sh_offset), shdr->sh_size);
+			if (shdr->sh_type == SHT_NOBITS) {
+				/* This is the .bss, zero it */
+				memset((void *)(shdr->sh_addr), 0x0, shdr->sh_size);
+			} else {
+				memcpy((void *)(shdr->sh_addr), (void *)((uintptr_t)header + shdr->sh_offset), shdr->sh_size);
+			}
+			char * sh_name = (char *)((uintptr_t)string_table + shdr->sh_name);
+			printf("%s %p\n", sh_name, shdr->sh_addr);
+			if (!strcmp(sh_name,".init")) {
+				__init = shdr->sh_addr;
+				printf("Found .init\n");
+			}
 		}
 	}
 
-	uintptr_t location = header->e_entry;
-	uintptr_t argc_    = (uintptr_t)&argc;
+	if (__init) {
+		printf("Calling _init()\n");
 		__asm__ __volatile__ (
-			"push %2\n"
-			"push %1\n"
-			"push $0\n"
 				"call *%0\n"
-			: : "m"(location), "m"(argc_), "m"(argv));
+				: : "m"(__init));
+	}
+
+
+	epoint = header->e_entry;
+	__asm__ __volatile__ (
+			"pushl $0\n"
+			"pushl %2\n"
+			"pushl %1\n"
+			"pushl $0xDECADE21\n"
+			"jmp *%0\n"
+			: : "m"(epoint), "r"(argc-1), "r"(argv+1));
 
 	return 0;
 }

util/readelf.c

@@ -35,7 +35,7 @@ int main(int argc, char ** argv) {
 	size_t binary_size;      /**< Size of the file */
 	char * binary_buf;       /**< Buffer to store the binary in memory */
 	Elf32_Header * header;   /**< ELF header */
-	char * string_table[5];  /**< Room for some string tables */
+	char * string_table;     /**< Room for some string tables */
 
 	/* Open the requested binary */
 	binary = fopen(argv[1], "r");
@@ -159,11 +159,11 @@ int main(int argc, char ** argv) {
 			return 1;
 		}
 		Elf32_Shdr * shdr = (Elf32_Shdr *)((uintptr_t)binary_buf + (header->e_shoff + x));
-		if (shdr->sh_type != SHT_STRTAB) continue;
-		string_table[i] = (char *)((uintptr_t)binary_buf + shdr->sh_offset);
+		if (i == header->e_shstrndx) {
+			string_table = (char *)((uintptr_t)binary_buf + shdr->sh_offset);
 			printf("Found a string table at 0x%x\n", shdr->sh_offset);
+		}
 		++i;
-		if (i == 5) break;
 	}
 
 	/* Read the section headers */
@@ -175,7 +175,7 @@ int main(int argc, char ** argv) {
 		}
 		Elf32_Shdr * shdr = (Elf32_Shdr *)((uintptr_t)binary_buf + (header->e_shoff + x));
 
-		printf("[%d] %s\n", shdr->sh_type, (char *)((uintptr_t)string_table[0] + shdr->sh_name));
+		printf("[%d] %s\n", shdr->sh_type, (char *)((uintptr_t)string_table + shdr->sh_name));
 		printf("Section starts at 0x%x and is 0x%x bytes long.\n", shdr->sh_offset, shdr->sh_size);
 		if (shdr->sh_addr) {
 			printf("It should be loaded at 0x%x.\n", shdr->sh_addr);