SystemMenuHook/source/elf_loading.c
2019-08-15 10:32:25 +02:00

105 lines
3.0 KiB
C

#include <stdio.h>
#include <string.h>
#include <coreinit/debug.h>
#include <coreinit/cache.h>
#include <coreinit/memdefaultheap.h>
#include <whb/sdcard.h>
#include <whb/file.h>
#include <whb/log.h>
#include "elf_abi.h"
#include "elf_loading.h"
int32_t LoadFileToMem(const char *relativefilepath, char **fileOut, uint32_t * sizeOut) {
char path[256];
int result = 0;
if (!WHBMountSdCard()) {
WHBLogPrintf("Failed to mount SD Card...");
result = -1;
goto exit;
}
char * sdRootPath = WHBGetSdCardMountPath();
sprintf(path, "%s/%s", sdRootPath,relativefilepath);
WHBLogPrintf("Loading file %s.",path);
*fileOut = WHBReadWholeFile(path, sizeOut);
if (!fileOut) {
result = -2;
WHBLogPrintf("WHBReadWholeFile(%s) returned NULL", path);
goto exit;
}
exit:
WHBUnmountSdCard();
return result;
}
uint32_t load_loader_elf(unsigned char* baseAddress, const char* relativePath) {
char * elf_data = NULL;
uint32_t fileSize = 0;
if(LoadFileToMem(relativePath, &elf_data, &fileSize) != 0) {
OSFatal("Failed to load hook elf from SD.");
}
Elf32_Ehdr *ehdr;
Elf32_Phdr *phdrs;
uint8_t *image;
int32_t i;
ehdr = (Elf32_Ehdr *) elf_data;
if(ehdr->e_phoff == 0 || ehdr->e_phnum == 0) {
return 0;
}
if(ehdr->e_phentsize != sizeof(Elf32_Phdr)) {
return 0;
}
phdrs = (Elf32_Phdr*)(elf_data + ehdr->e_phoff);
for(i = 0; i < ehdr->e_phnum; i++) {
if(phdrs[i].p_type != PT_LOAD) {
continue;
}
if(phdrs[i].p_filesz > phdrs[i].p_memsz) {
continue;
}
if(!phdrs[i].p_filesz) {
continue;
}
uint32_t p_paddr = phdrs[i].p_paddr + (uint32_t)baseAddress;
image = (uint8_t *) (elf_data + phdrs[i].p_offset);
memcpy ((void *) p_paddr, image, phdrs[i].p_filesz);
DCFlushRange((void*)p_paddr, phdrs[i].p_filesz);
if(phdrs[i].p_flags & PF_X) {
ICInvalidateRange ((void *) p_paddr, phdrs[i].p_memsz);
}
}
//! clear BSS
Elf32_Shdr *shdr = (Elf32_Shdr *) (elf_data + ehdr->e_shoff);
for(i = 0; i < ehdr->e_shnum; i++) {
const char *section_name = ((const char*)elf_data) + shdr[ehdr->e_shstrndx].sh_offset + shdr[i].sh_name;
if(section_name[0] == '.' && section_name[1] == 'b' && section_name[2] == 's' && section_name[3] == 's') {
memset((void*)(shdr[i].sh_addr + baseAddress), 0, shdr[i].sh_size);
DCFlushRange((void*)(shdr[i].sh_addr + baseAddress), shdr[i].sh_size);
} else if(section_name[0] == '.' && section_name[1] == 's' && section_name[2] == 'b' && section_name[3] == 's' && section_name[4] == 's') {
memset((void*)(shdr[i].sh_addr + baseAddress), 0, shdr[i].sh_size);
DCFlushRange((void*)(shdr[i].sh_addr + baseAddress), shdr[i].sh_size);
}
}
MEMFreeToDefaultHeap((void*)elf_data);
return ehdr->e_entry;
}