Magisk/jni/repack.c

145 lines
3.4 KiB
C
Raw Normal View History

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/sendfile.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <assert.h>
#include <string.h>
#include "bootimgtools.h"
off_t file_size(char *filename) {
struct stat st;
if(stat(filename, &st))
exit(1);
return st.st_size;
}
int append_file(int ofd, char *filename, off_t pos) {
lseek(ofd, pos, SEEK_SET);
int fd = open(filename, O_RDONLY);
int size = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
sendfile(ofd, fd, NULL, size);
close(fd);
return size;
}
int append_ramdisk(int ofd, off_t pos) {
if(access("ramdisk-mtk", R_OK) == 0) {
char buf[512];
off_t size = file_size("ramdisk.gz");
memcpy(buf, "\x88\x16\x88\x58", 4);
uint32_t v = size;
memcpy(buf+4, &v, sizeof(v)); //Should convert to LE
//TODO: RECOVERY OR ROOTFS?
char str[32];
memset(str, 0, sizeof(str));
if(access("ramdisk-mtk-boot", R_OK)==0) {
strcpy(str, "ROOTFS");
} else if(access("ramdisk-mtk-recovery", R_OK)==0) {
strcpy(str, "RECOVERY");
} else {
exit(1);
}
memcpy(buf+8, str, sizeof(str));
memset(buf+8+sizeof(str), 0xff, 512-8-sizeof(str));
pwrite(ofd, buf, sizeof(buf), pos);
return append_file(ofd, "ramdisk.gz", pos + 512) + 512;
} else if(access("ramdisk.gz", R_OK) == 0) {
return append_file(ofd, "ramdisk.gz", pos);
} else {
return append_file(ofd, "ramdisk", pos);
}
}
void post_process(struct boot_img_hdr *hdr, int ofd, int pos) {
if(access("rkcrc", R_OK) == 0) {
fprintf(stderr, "Rockchip CRCs not supported yet\n");
exit(1);
}
//Round up the file size
ftruncate(ofd, pos);
}
int repack(char *image) {
//TODO: Merge with extract.c?
//{
int ifd = open(image, O_RDONLY);
off_t isize = lseek(ifd, 0, SEEK_END);
lseek(ifd, 0, SEEK_SET);
uint8_t *iorig = mmap(NULL, isize, PROT_READ, MAP_SHARED, ifd, 0);
uint8_t *ibase = iorig;
assert(ibase);
while(ibase<(iorig+isize)) {
if(memcmp(ibase, BOOT_MAGIC, BOOT_MAGIC_SIZE) == 0)
break;
ibase += 256;
}
assert(ibase < (iorig+isize));
//}
//
struct boot_img_hdr *ihdr = (struct boot_img_hdr*) ibase;
assert(
ihdr->page_size == 2048 ||
ihdr->page_size == 4096 ||
ihdr->page_size == 16384
);
unlink("new-boot.img");
int ofd = open("new-boot.img", O_RDWR|O_CREAT, 0644);
ftruncate(ofd, ihdr->page_size);
//Write back original header, we'll change it later
write(ofd, ihdr, sizeof(*ihdr));
struct boot_img_hdr *hdr = mmap(NULL, sizeof(*ihdr), PROT_READ|PROT_WRITE, MAP_SHARED, ofd, 0);
//First set everything to zero, so we know where we are at.
hdr->kernel_size = 0;
hdr->ramdisk_size = 0;
hdr->second_size = 0;
hdr->unused[0] = 0;
memset(hdr->id, 0, sizeof(hdr->id)); //Setting id to 0 might be wrong?
int pos = hdr->page_size;
int size = 0;
size = append_file(ofd, "kernel", pos);
pos += size + hdr->page_size - 1;
pos &= ~(hdr->page_size-1);
hdr->kernel_size = size;
size = append_ramdisk(ofd, pos);
pos += size + hdr->page_size - 1;
pos &= ~(hdr->page_size-1);
hdr->ramdisk_size = size;
if(access("second", R_OK) == 0) {
size = append_file(ofd, "second", pos);
pos += size + hdr->page_size - 1;
pos &= ~(hdr->page_size-1);
hdr->second_size = size;
}
if(access("dt", R_OK) == 0) {
size = append_file(ofd, "dt", pos);
pos += size + hdr->page_size - 1;
pos &= ~(hdr->page_size-1);
hdr->unused[0] = size;
}
post_process(hdr, ofd, pos);
munmap(hdr, sizeof(*ihdr));
close(ofd);
return 0;
}