Magisk/jni/magiskboot/repack.c
2017-03-04 21:16:59 +08:00

111 lines
2.4 KiB
C

#include "magiskboot.h"
static size_t restore(const char *filename, int fd) {
int ifd = open(filename, O_RDONLY);
if (ifd < 0)
error(1, "Cannot open %s\n", filename);
size_t size = lseek(ifd, 0, SEEK_END);
lseek(ifd, 0, SEEK_SET);
if (sendfile(fd, ifd, NULL, size) != size) {
error(1, "Cannot write %s\n", filename);
}
close(ifd);
return size;
}
static void restore_buf(const void *buf, size_t size, int fd) {
if (write(fd, buf, size) != size) {
error(1, "Cannot dump from input file\n");
}
}
void repack(const char* image) {
size_t size;
unsigned char *orig;
char name[PATH_MAX];
#define EXT_NUM 6
char *ext_list[EXT_NUM] = { "gz", "lzo", "xz", "lzma", "bz2", "lz4" };
// Load original image
mmap_ro(image, &orig, &size);
// Parse original image
parse_img(orig, size);
// Create new image
int fd = open_new("new-boot.img");
// 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
ftruncate(fd, hdr.page_size);
lseek(fd, 0, SEEK_END);
// Restore kernel
if (mtk_kernel) {
restore_buf(kernel, 512, fd);
hdr.kernel_size += 512;
}
hdr.kernel_size += restore(KERNEL_FILE, fd);
file_align(fd, hdr.page_size);
// Restore ramdisk
if (mtk_ramdisk) {
restore_buf(ramdisk, 512, fd);
hdr.ramdisk_size += 512;
}
if (access(RAMDISK_FILE, R_OK) == 0) {
// If we found raw cpio, compress to original format
size_t cpio_size;
unsigned char *cpio;
mmap_ro(RAMDISK_FILE, &cpio, &cpio_size);
if (comp(ramdisk_type, RAMDISK_FILE, cpio, cpio_size))
error(1, "Unsupported format! Please compress manually!");
munmap(cpio, cpio_size);
}
int found = 0;
for (int i = 0; i < EXT_NUM; ++i) {
sprintf(name, "%s.%s", RAMDISK_FILE, ext_list[i]);
if (access(name, R_OK) == 0) {
found = 1;
break;
}
}
if (!found)
error(1, "No ramdisk exists!");
hdr.ramdisk_size += restore(name, fd);
file_align(fd, hdr.page_size);
// Restore second
if (access(SECOND_FILE, R_OK) == 0) {
hdr.second_size += restore(SECOND_FILE, fd);
file_align(fd, hdr.page_size);
}
// Restore dtb
if (access(DTB_FILE, R_OK) == 0) {
hdr.dt_size += restore(DTB_FILE, fd);
file_align(fd, hdr.page_size);
}
// Write header back
lseek(fd, 0, SEEK_SET);
write(fd, &hdr, sizeof(hdr));
munmap(orig, size);
if (lseek(fd, 0, SEEK_CUR) > size) {
error(2, "Boot partition too small!");
}
close(fd);
}