[sys] Various.

This commit is contained in:
Kevin Lange 2011-04-29 12:43:09 -05:00
parent 03a8066742
commit 4b218387e7
3 changed files with 200 additions and 0 deletions

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@ -67,6 +67,7 @@ static int write(int fd, char * ptr, int len) {
if (fd == 1 || fd == 2) {
for (int i = 0; i < len; ++i) {
ansi_put(ptr[i]);
serial_send(ptr[i]);
}
return len;
}

189
loader/ld.c Normal file
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@ -0,0 +1,189 @@
/*
* ToAruOS Loader
* (C) 2011 Kevin Lange
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
/* The Master ELF Header */
#include "../kernel/include/elf.h"
/**
* Show usage for the readelf application.
* @param argc Argument count (unused)
* @param argv Arguments to binary
*/
void usage(int argc, char ** argv) {
/* Show usage */
printf("%s [filename]\n", argv[0]);
printf("Loads a /static/ binary into memory and executes it.\n");
exit(1);
}
/**
* Application entry point.
* @returns 0 on sucess, 1 on failure
*/
int main(int argc, char ** argv) {
/* Process arguments */
if (argc < 2) usage(argc,argv);
FILE * binary; /**< File pointer for requested executable */
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 */
/* 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;
}
printf("Binary is %u bytes.\n", binary_size);
fclose(binary);
binary = fopen(argv[1], "r");
/* Read the binary into a buffer */
binary_buf = malloc(binary_size);
fread((void *)binary_buf, binary_size, 1, binary);
/* Let's start considering this guy an elf, 'eh? */
header = (Elf32_Header *)binary_buf;
/* Verify the magic */
if ( header->e_ident[0] != ELFMAG0 ||
header->e_ident[1] != ELFMAG1 ||
header->e_ident[2] != ELFMAG2 ||
header->e_ident[3] != ELFMAG3) {
printf("Header magic is wrong!\n");
printf("Are you sure this is a 32-bit ELF binary or object file?\n");
return 1;
}
/* Let's print out some of the header information, shall we? */
printf("\033[1mELF Header\033[0m\n");
/* File type */
printf("[Type %d] ", header->e_type);
switch (header->e_type) {
case ET_NONE:
printf("No file type.\n");
break;
case ET_REL:
printf("Relocatable file.\n");
break;
case ET_EXEC:
printf("Executable file.\n");
break;
case ET_DYN:
printf("Shared object file.\n");
break;
case ET_CORE:
printf("Core file.\n");
break;
default:
printf("(Unknown file type)\n");
break;
}
/* Machine Type */
switch (header->e_machine) {
case EM_386:
printf("Intel x86\n");
break;
default:
printf("Unknown machine: %d\n", header->e_machine);
break;
}
/* Version == EV_CURRENT? */
if (header->e_version == EV_CURRENT) {
printf("ELF version is 1, as it should be.\n");
}
/* Entry point in memory */
printf("Binary entry point in virtual memory is at 0x%x\n", header->e_entry);
/* Program header table offset */
printf("Program header table is at +0x%x and one entry is 0x%x bytes.\n"
"There are %d total program headers.\n",
header->e_phoff, header->e_phentsize, header->e_phnum);
/* Section header table offset */
printf("Section header table is at +0x%x and one entry is 0x%x bytes.\n"
"There are %d total section headers.\n",
header->e_shoff, header->e_shentsize, header->e_shnum);
/* Read the program headers */
printf("\033[1mProgram Headers\033[0m\n");
for (uint32_t x = 0; x < header->e_phentsize * header->e_phnum; x += header->e_phentsize) {
if (header->e_phoff + x > binary_size) {
printf("Tried to read beyond the end of the file.\n");
return 1;
}
/* Grab the program header */
Elf32_Phdr * phdr = (Elf32_Phdr *)((uintptr_t)binary_buf + (header->e_phoff + x));
/* Print the header type */
switch (phdr->p_type) {
case PT_LOAD:
printf("[Loadable Segment]\n");
break;
case PT_DYNAMIC:
printf("[Dynamic Loading Information]\n");
break;
case PT_INTERP:
printf("[Interpreter Path]\n");
break;
default:
printf("[Unused Segement]\n");
break;
}
}
/* Find the (hopefully two) string tables */
printf("\033[1mString Tables\033[0m\n");
uint32_t i = 0;
for (uint32_t x = 0; x < header->e_shentsize * header->e_shnum; x += header->e_shentsize) {
if (header->e_shoff + x > binary_size) {
printf("Tried to read beyond the end of the file.\n");
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);
printf("Found a string table at 0x%x\n", shdr->sh_offset);
++i;
if (i == 5) break;
}
/* Read the section headers */
printf("\033[1mSection Headers\033[0m\n");
for (uint32_t x = 0; x < header->e_shentsize * header->e_shnum; x += header->e_shentsize) {
if (header->e_shoff + x > binary_size) {
printf("Tried to read beyond the end of the file.\n");
return 1;
}
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("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);
}
}
return 0;
}
/*
* vim:noexpandtab
* vim:tabstop=4
* vim:shiftwidth=4
*/

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@ -40,6 +40,7 @@ int main(int argc, char ** argv) {
/* Open the requested binary */
binary = fopen(argv[1], "r");
#if 0
/* Jump to the end so we can get the size */
fseek(binary, 0, SEEK_END);
binary_size = ftell(binary);
@ -50,6 +51,15 @@ int main(int argc, char ** argv) {
printf("Oh no! I don't quite like the size of this binary.\n");
return 1;
}
#endif
char garbage[3];
binary_size = 0;
while (fread((void *)&garbage, 1, 1, binary) != 0) {
++binary_size;
}
printf("Binary is %d bytes.\n", binary_size);
fclose(binary);
binary = fopen(argv[1], "r");
/* Read the binary into a buffer */
binary_buf = malloc(binary_size);