Magisk/jni/magiskboot/repack.c

137 lines
3.3 KiB
C

#include "magiskboot.h"
static size_t restore(const char *filename, int fd) {
int ifd = xopen(filename, O_RDONLY);
size_t size = lseek(ifd, 0, SEEK_END);
lseek(ifd, 0, SEEK_SET);
xsendfile(fd, ifd, NULL, size);
close(ifd);
return size;
}
static void restore_buf(int fd, const void *buf, size_t size) {
xwrite(fd, buf, size);
}
void repack(const char* orig_image, const char* out_image) {
size_t size;
unsigned char *orig;
char name[PATH_MAX];
// There are possible two MTK headers
mtk_hdr mtk_kernel_hdr, mtk_ramdisk_hdr;
size_t mtk_kernel_off, mtk_ramdisk_off;
// Load original image
mmap_ro(orig_image, &orig, &size);
// Parse original image
printf("Parsing boot image: [%s]\n\n", orig_image);
parse_img(orig, size);
printf("Repack to boot image: [%s]\n\n", out_image);
// Create new image
int fd = open_new(out_image);
// Set all sizes to 0
hdr.kernel_size = 0;
hdr.ramdisk_size = 0;
hdr.second_size = 0;
hdr.dt_size = 0;
// Skip a page for header
write_zero(fd, hdr.page_size);
// Restore kernel
if (mtk_kernel) {
mtk_kernel_off = lseek(fd, 0, SEEK_CUR);
restore_buf(fd, kernel, 512);
memcpy(&mtk_kernel_hdr, kernel, sizeof(mtk_kernel_hdr));
}
hdr.kernel_size = restore(KERNEL_FILE, fd);
file_align(fd, hdr.page_size, 1);
// Restore ramdisk
if (mtk_ramdisk) {
mtk_ramdisk_off = lseek(fd, 0, SEEK_CUR);
restore_buf(fd, ramdisk, 512);
memcpy(&mtk_ramdisk_hdr, ramdisk, sizeof(mtk_ramdisk_hdr));
}
if (access(RAMDISK_FILE, R_OK) == 0) {
// If we found raw cpio, compress to original format
// Before we start, clean up previous compressed files
for (int i = 0; SUP_EXT_LIST[i]; ++i) {
sprintf(name, "%s.%s", RAMDISK_FILE, SUP_EXT_LIST[i]);
unlink(name);
}
size_t cpio_size;
unsigned char *cpio;
mmap_ro(RAMDISK_FILE, &cpio, &cpio_size);
if (comp(ramdisk_type, RAMDISK_FILE, cpio, cpio_size))
LOGE(1, "Unsupported ramdisk format!\n");
munmap(cpio, cpio_size);
}
int found = 0;
for (int i = 0; SUP_EXT_LIST[i]; ++i) {
sprintf(name, "%s.%s", RAMDISK_FILE, SUP_EXT_LIST[i]);
if (access(name, R_OK) == 0) {
ramdisk_type = SUP_TYPE_LIST[i];
found = 1;
break;
}
}
if (!found)
LOGE(1, "No ramdisk exists!\n");
hdr.ramdisk_size = restore(name, fd);
file_align(fd, hdr.page_size, 1);
// Restore second
if (access(SECOND_FILE, R_OK) == 0) {
hdr.second_size = restore(SECOND_FILE, fd);
file_align(fd, hdr.page_size, 1);
}
// Restore dtb
if (access(DTB_FILE, R_OK) == 0) {
hdr.dt_size = restore(DTB_FILE, fd);
file_align(fd, hdr.page_size, 1);
}
// Check extra info, currently only for LG Bump and Samsung SEANDROIDENFORCE
if (extra) {
if (memcmp(extra, "SEANDROIDENFORCE", 16) == 0 ||
memcmp(extra, "\x41\xa9\xe4\x67\x74\x4d\x1d\x1b\xa4\x29\xf2\xec\xea\x65\x52\x79", 16) == 0 ) {
restore_buf(fd, extra, 16);
}
}
// Write headers back
if (mtk_kernel) {
lseek(fd, mtk_kernel_off, SEEK_SET);
mtk_kernel_hdr.size = hdr.kernel_size;
hdr.kernel_size += 512;
restore_buf(fd, &mtk_kernel_hdr, sizeof(mtk_kernel_hdr));
}
if (mtk_ramdisk) {
lseek(fd, mtk_ramdisk_off, SEEK_SET);
mtk_ramdisk_hdr.size = hdr.ramdisk_size;
hdr.ramdisk_size += 512;
restore_buf(fd, &mtk_ramdisk_hdr, sizeof(mtk_ramdisk_hdr));
}
// Main header
lseek(fd, 0, SEEK_SET);
restore_buf(fd, &hdr, sizeof(hdr));
// Print new image info
print_info();
munmap(orig, size);
close(fd);
}