Magisk/native/jni/magiskboot/bootimg.cpp

#include <sys/mman.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <libfdt.h>
#include <functional>
#include <memory>

#include <mincrypt/sha.h>
#include <mincrypt/sha256.h>
#include <utils.hpp>

#include "bootimg.hpp"
#include "magiskboot.hpp"
#include "compress.hpp"

using namespace std;

uint32_t dyn_img_hdr::j32 = 0;
uint64_t dyn_img_hdr::j64 = 0;

#define PADDING 15

static void decompress(format_t type, int fd, const void *in, size_t size) {
    auto ptr = get_decoder(type, make_unique<fd_stream>(fd));
    ptr->write(in, size);
}

static off_t compress(format_t type, int fd, const void *in, size_t size) {
    auto prev = lseek(fd, 0, SEEK_CUR);
    {
        auto strm = get_encoder(type, make_unique<fd_stream>(fd));
        strm->write(in, size);
    }
    auto now = lseek(fd, 0, SEEK_CUR);
    return now - prev;
}

static void dump(void *buf, size_t size, const char *filename) {
    if (size == 0)
        return;
    int fd = creat(filename, 0644);
    xwrite(fd, buf, size);
    close(fd);
}

static size_t restore(int fd, const char *filename) {
    int ifd = xopen(filename, O_RDONLY);
    size_t size = lseek(ifd, 0, SEEK_END);
    lseek(ifd, 0, SEEK_SET);
    xsendfile(fd, ifd, nullptr, size);
    close(ifd);
    return size;
}

static void restore_buf(int fd, const void *buf, size_t size) {
    xwrite(fd, buf, size);
}

void dyn_img_hdr::print() {
    uint32_t ver = header_version();
    fprintf(stderr, "%-*s [%u]\n", PADDING, "HEADER_VER", ver);
    fprintf(stderr, "%-*s [%u]\n", PADDING, "KERNEL_SZ", kernel_size());
    fprintf(stderr, "%-*s [%u]\n", PADDING, "RAMDISK_SZ", ramdisk_size());
    if (ver < 3)
        fprintf(stderr, "%-*s [%u]\n", PADDING, "SECOND_SZ", second_size());
    if (ver == 0)
        fprintf(stderr, "%-*s [%u]\n", PADDING, "EXTRA_SZ", extra_size());
    if (ver == 1 || ver == 2)
        fprintf(stderr, "%-*s [%u]\n", PADDING, "RECOV_DTBO_SZ", recovery_dtbo_size());
    if (ver == 2)
        fprintf(stderr, "%-*s [%u]\n", PADDING, "DTB_SZ", dtb_size());

    if (uint32_t os_ver = os_version()) {
        int a,b,c,y,m = 0;
        int version = os_ver >> 11;
        int patch_level = os_ver & 0x7ff;

        a = (version >> 14) & 0x7f;
        b = (version >> 7) & 0x7f;
        c = version & 0x7f;
        fprintf(stderr, "%-*s [%d.%d.%d]\n", PADDING, "OS_VERSION", a, b, c);

        y = (patch_level >> 4) + 2000;
        m = patch_level & 0xf;
        fprintf(stderr, "%-*s [%d-%02d]\n", PADDING, "OS_PATCH_LEVEL", y, m);
    }

    fprintf(stderr, "%-*s [%u]\n", PADDING, "PAGESIZE", page_size());
    if (ver < 3) {
        fprintf(stderr, "%-*s [%s]\n", PADDING, "NAME", name());
    }
    fprintf(stderr, "%-*s [%.*s%.*s]\n", PADDING, "CMDLINE",
            BOOT_ARGS_SIZE, cmdline(), BOOT_EXTRA_ARGS_SIZE, extra_cmdline());
    if (auto chksum = reinterpret_cast<uint8_t*>(id())) {
        fprintf(stderr, "%-*s [", PADDING, "CHECKSUM");
        for (int i = 0; i < SHA256_DIGEST_SIZE; ++i)
            fprintf(stderr, "%02hhx", chksum[i]);
        fprintf(stderr, "]\n");
    }
}

void dyn_img_hdr::dump_hdr_file() {
    FILE *fp = xfopen(HEADER_FILE, "w");
    fprintf(fp, "pagesize=%u\n", page_size());
    if (name())
        fprintf(fp, "name=%s\n", name());
    fprintf(fp, "cmdline=%.*s%.*s\n", BOOT_ARGS_SIZE, cmdline(), BOOT_EXTRA_ARGS_SIZE, extra_cmdline());
    uint32_t ver = os_version();
    if (ver) {
        int a, b, c, y, m;
        int version, patch_level;
        version = ver >> 11;
        patch_level = ver & 0x7ff;

        a = (version >> 14) & 0x7f;
        b = (version >> 7) & 0x7f;
        c = version & 0x7f;
        fprintf(fp, "os_version=%d.%d.%d\n", a, b, c);

        y = (patch_level >> 4) + 2000;
        m = patch_level & 0xf;
        fprintf(fp, "os_patch_level=%d-%02d\n", y, m);
    }
    fclose(fp);
}

void dyn_img_hdr::load_hdr_file() {
    parse_prop_file(HEADER_FILE, [=](string_view key, string_view value) -> bool {
        if (key == "page_size") {
            page_size() = parse_int(value);
        } else if (key == "name" && name()) {
            memset(name(), 0, 16);
            memcpy(name(), value.data(), value.length() > 15 ? 15 : value.length());
        } else if (key == "cmdline") {
            memset(cmdline(), 0, BOOT_ARGS_SIZE);
            memset(extra_cmdline(), 0, BOOT_EXTRA_ARGS_SIZE);
            if (value.length() > BOOT_ARGS_SIZE) {
                memcpy(cmdline(), value.data(), BOOT_ARGS_SIZE);
                auto len = std::min(value.length() - BOOT_ARGS_SIZE, (size_t) BOOT_EXTRA_ARGS_SIZE);
                memcpy(extra_cmdline(), &value[BOOT_ARGS_SIZE], len);
            } else {
                memcpy(cmdline(), value.data(), value.length());
            }
        } else if (key == "os_version") {
            int patch_level = os_version() & 0x7ff;
            int a, b, c;
            sscanf(value.data(), "%d.%d.%d", &a, &b, &c);
            os_version() = (((a << 14) | (b << 7) | c) << 11) | patch_level;
        } else if (key == "os_patch_level") {
            int os_ver = os_version() >> 11;
            int y, m;
            sscanf(value.data(), "%d-%d", &y, &m);
            y -= 2000;
            os_version() = (os_ver << 11) | (y << 4) | m;
        }
        return true;
    });
}

boot_img::boot_img(const char *image) {
    mmap_ro(image, map_addr, map_size);
    fprintf(stderr, "Parsing boot image: [%s]\n", image);
    for (uint8_t *addr = map_addr; addr < map_addr + map_size; ++addr) {
        format_t fmt = check_fmt(addr, map_size);
        switch (fmt) {
        case CHROMEOS:
            // chromeos require external signing
            flags |= CHROMEOS_FLAG;
            addr += 65535;
            break;
        case DHTB:
            flags |= (DHTB_FLAG | SEANDROID_FLAG);
            fprintf(stderr, "DHTB_HDR\n");
            addr += sizeof(dhtb_hdr) - 1;
            break;
        case BLOB:
            flags |= BLOB_FLAG;
            fprintf(stderr, "TEGRA_BLOB\n");
            addr += sizeof(blob_hdr) - 1;
            break;
        case AOSP:
        case AOSP_VENDOR:
            parse_image(addr, fmt);
            return;
        default:
            break;
        }
    }
    exit(1);
}

boot_img::~boot_img() {
    munmap(map_addr, map_size);
    delete hdr;
}

static int find_dtb_offset(uint8_t *buf, unsigned sz) {
    for (int off = 0; off + sizeof(fdt_header) < sz; ++off) {
        auto fdt_hdr = reinterpret_cast<fdt_header *>(buf + off);
        if (fdt32_to_cpu(fdt_hdr->magic) != FDT_MAGIC)
            continue;

        // Check that fdt_header.totalsize does not overflow kernel image size
        uint32_t totalsize = fdt32_to_cpu(fdt_hdr->totalsize);
        if (totalsize + off > sz)
            continue;

        // Check that fdt_header.off_dt_struct does not overflow kernel image size
        uint32_t off_dt_struct = fdt32_to_cpu(fdt_hdr->off_dt_struct);
        if (off_dt_struct + off > sz)
            continue;

        // Check that fdt_node_header.tag of first node is FDT_BEGIN_NODE
        auto fdt_node_hdr = reinterpret_cast<fdt_node_header *>(buf + off + off_dt_struct);
        if (fdt32_to_cpu(fdt_node_hdr->tag) != FDT_BEGIN_NODE)
            continue;

        return off;
    }
    return -1;
}

static format_t check_fmt_lg(uint8_t *buf, unsigned sz) {
    format_t fmt = check_fmt(buf, sz);
    if (fmt == LZ4_LEGACY) {
        // We need to check if it is LZ4_LG
        unsigned off = 4;
        unsigned block_sz;
        while (off + sizeof(block_sz) <= sz) {
            memcpy(&block_sz, buf + off, sizeof(block_sz));
            off += sizeof(block_sz);
            if (off + block_sz > sz)
                return LZ4_LG;
            off += block_sz;
        }
    }
    return fmt;
}

#define get_block(name) {\
name = addr + off; \
off += hdr->name##_size(); \
off = do_align(off, hdr->page_size()); \
}

void boot_img::parse_image(uint8_t *addr, format_t type) {
    auto hp = reinterpret_cast<boot_img_hdr*>(addr);
    if (type == AOSP_VENDOR) {
        fprintf(stderr, "VENDOR_BOOT_HDR\n");
        hdr = new dyn_img_vnd_v3(addr);
    } else if (hp->page_size >= 0x02000000) {
        fprintf(stderr, "PXA_BOOT_HDR\n");
        hdr = new dyn_img_pxa(addr);
    } else {
        if (memcmp(hp->cmdline, NOOKHD_RL_MAGIC, 10) == 0 ||
            memcmp(hp->cmdline, NOOKHD_GL_MAGIC, 12) == 0 ||
            memcmp(hp->cmdline, NOOKHD_GR_MAGIC, 14) == 0 ||
            memcmp(hp->cmdline, NOOKHD_EB_MAGIC, 26) == 0 ||
            memcmp(hp->cmdline, NOOKHD_ER_MAGIC, 30) == 0) {
            flags |= NOOKHD_FLAG;
            fprintf(stderr, "NOOKHD_LOADER\n");
            addr += NOOKHD_PRE_HEADER_SZ;
        } else if (memcmp(hp->name, ACCLAIM_MAGIC, 10) == 0) {
            flags |= ACCLAIM_FLAG;
            fprintf(stderr, "ACCLAIM_LOADER\n");
            addr += ACCLAIM_PRE_HEADER_SZ;
        }

        switch (hp->header_version) {
        case 1:
            hdr = new dyn_img_v1(addr);
            break;
        case 2:
            hdr = new dyn_img_v2(addr);
            break;
        case 3:
            hdr = new dyn_img_v3(addr);
            break;
        default:
            hdr = new dyn_img_v0(addr);
            break;
        }
    }

    if (char *id = hdr->id()) {
        for (int i = SHA_DIGEST_SIZE + 4; i < SHA256_DIGEST_SIZE; ++i) {
            if (id[i]) {
                flags |= SHA256_FLAG;
                break;
            }
        }
    }

    hdr->print();

    size_t off = hdr->hdr_space();
    hdr_addr = addr;
    get_block(kernel);
    get_block(ramdisk);
    get_block(second);
    get_block(extra);
    get_block(recovery_dtbo);
    get_block(dtb);

    if (addr + off < map_addr + map_size) {
        tail = addr + off;
        tail_size = map_size - (tail - map_addr);
    }

    // Check tail info, currently only for LG Bump and Samsung SEANDROIDENFORCE
    if (tail_size >= 16 && memcmp(tail, SEANDROID_MAGIC, 16) == 0) {
        flags |= SEANDROID_FLAG;
    } else if (tail_size >= 16 && memcmp(tail, LG_BUMP_MAGIC, 16) == 0) {
        flags |= LG_BUMP_FLAG;
    }

    if (int dtb_off = find_dtb_offset(kernel, hdr->kernel_size()); dtb_off > 0) {
        kernel_dtb = kernel + dtb_off;
        kernel_dt_size = hdr->kernel_size() - dtb_off;
        hdr->kernel_size() = dtb_off;
        fprintf(stderr, "%-*s [%u]\n", PADDING, "KERNEL_DTB", kernel_dt_size);
    }

    if (auto size = hdr->kernel_size()) {
        k_fmt = check_fmt_lg(kernel, size);
        if (k_fmt == MTK) {
            fprintf(stderr, "MTK_KERNEL_HDR\n");
            flags |= MTK_KERNEL;
            k_hdr = reinterpret_cast<mtk_hdr *>(kernel);
            fprintf(stderr, "%-*s [%u]\n", PADDING, "KERNEL", k_hdr->size);
            fprintf(stderr, "%-*s [%s]\n", PADDING, "NAME", k_hdr->name);
            kernel += sizeof(mtk_hdr);
            hdr->kernel_size() -= sizeof(mtk_hdr);
            k_fmt = check_fmt_lg(kernel, hdr->kernel_size());
        }
        fprintf(stderr, "%-*s [%s]\n", PADDING, "KERNEL_FMT", fmt2name[k_fmt]);
    }
    if (auto size = hdr->ramdisk_size()) {
        r_fmt = check_fmt_lg(ramdisk, size);
        if (r_fmt == MTK) {
            fprintf(stderr, "MTK_RAMDISK_HDR\n");
            flags |= MTK_RAMDISK;
            r_hdr = reinterpret_cast<mtk_hdr *>(ramdisk);
            fprintf(stderr, "%-*s [%u]\n", PADDING, "RAMDISK", r_hdr->size);
            fprintf(stderr, "%-*s [%s]\n", PADDING, "NAME", r_hdr->name);
            ramdisk += sizeof(mtk_hdr);
            hdr->ramdisk_size() -= sizeof(mtk_hdr);
            r_fmt = check_fmt_lg(ramdisk, hdr->ramdisk_size());
        }
        fprintf(stderr, "%-*s [%s]\n", PADDING, "RAMDISK_FMT", fmt2name[r_fmt]);
    }
    if (auto size = hdr->extra_size()) {
        e_fmt = check_fmt_lg(extra, size);
        fprintf(stderr, "%-*s [%s]\n", PADDING, "EXTRA_FMT", fmt2name[e_fmt]);
    }
}

int split_image_dtb(const char *filename) {
    uint8_t *buf;
    size_t sz;
    mmap_ro(filename, buf, sz);
    run_finally f([=]{ munmap(buf, sz); });

    if (int off = find_dtb_offset(buf, sz); off > 0) {
        format_t fmt = check_fmt_lg(buf, sz);
        if (COMPRESSED(fmt)) {
            int fd = creat(KERNEL_FILE, 0644);
            decompress(fmt, fd, buf, off);
            close(fd);
        } else {
            dump(buf, off, KERNEL_FILE);
        }
        dump(buf + off, sz - off, KER_DTB_FILE);
        return 0;
    } else {
        fprintf(stderr, "Cannot find DTB in %s\n", filename);
        return 1;
    }
}

int unpack(const char *image, bool skip_decomp, bool hdr) {
    boot_img boot(image);

    if (hdr)
        boot.hdr->dump_hdr_file();

    // Dump kernel
    if (!skip_decomp && COMPRESSED(boot.k_fmt)) {
        int fd = creat(KERNEL_FILE, 0644);
        decompress(boot.k_fmt, fd, boot.kernel, boot.hdr->kernel_size());
        close(fd);
    } else {
        dump(boot.kernel, boot.hdr->kernel_size(), KERNEL_FILE);
    }

    // Dump kernel_dtb
    dump(boot.kernel_dtb, boot.kernel_dt_size, KER_DTB_FILE);

    // Dump ramdisk
    if (!skip_decomp && COMPRESSED(boot.r_fmt)) {
        int fd = creat(RAMDISK_FILE, 0644);
        decompress(boot.r_fmt, fd, boot.ramdisk, boot.hdr->ramdisk_size());
        close(fd);
    } else {
        dump(boot.ramdisk, boot.hdr->ramdisk_size(), RAMDISK_FILE);
    }

    // Dump second
    dump(boot.second, boot.hdr->second_size(), SECOND_FILE);

    // Dump extra
    if (!skip_decomp && COMPRESSED(boot.e_fmt)) {
        int fd = creat(EXTRA_FILE, 0644);
        decompress(boot.e_fmt, fd, boot.extra, boot.hdr->extra_size());
        close(fd);
    } else {
        dump(boot.extra, boot.hdr->extra_size(), EXTRA_FILE);
    }

    // Dump recovery_dtbo
    dump(boot.recovery_dtbo, boot.hdr->recovery_dtbo_size(), RECV_DTBO_FILE);

    // Dump dtb
    dump(boot.dtb, boot.hdr->dtb_size(), DTB_FILE);

    return (boot.flags & CHROMEOS_FLAG) ? 2 : 0;
}

#define file_align() \
write_zero(fd, align_off(lseek(fd, 0, SEEK_CUR) - off.header, boot.hdr->page_size()))

void repack(const char* src_img, const char* out_img, bool skip_comp) {
    boot_img boot(src_img);

    auto is_flag = [&](unsigned flag) -> bool { return (boot.flags & flag); };

    struct {
        uint32_t header;
        uint32_t kernel;
        uint32_t ramdisk;
        uint32_t second;
        uint32_t extra;
        uint32_t dtb;
        uint32_t total;
    } off;

    fprintf(stderr, "Repack to boot image: [%s]\n", out_img);

    // Reset sizes
    boot.hdr->kernel_size() = 0;
    boot.hdr->ramdisk_size() = 0;
    boot.hdr->second_size() = 0;
    boot.hdr->dtb_size() = 0;
    boot.kernel_dt_size = 0;

    if (access(HEADER_FILE, R_OK) == 0)
        boot.hdr->load_hdr_file();

    /*****************
     * Writing blocks
     *****************/

    // Create new image
    int fd = creat(out_img, 0644);

    if (is_flag(DHTB_FLAG)) {
        // Skip DHTB header
        write_zero(fd, sizeof(dhtb_hdr));
    } else if (is_flag(BLOB_FLAG)) {
        restore_buf(fd, boot.map_addr, sizeof(blob_hdr));
    } else if (is_flag(NOOKHD_FLAG)) {
        restore_buf(fd, boot.map_addr, NOOKHD_PRE_HEADER_SZ);
    } else if (is_flag(ACCLAIM_FLAG)) {
        restore_buf(fd, boot.map_addr, ACCLAIM_PRE_HEADER_SZ);
    }

    // Copy header
    off.header = lseek(fd, 0, SEEK_CUR);
    restore_buf(fd, boot.hdr_addr, boot.hdr->hdr_space());

    // kernel
    off.kernel = lseek(fd, 0, SEEK_CUR);
    if (is_flag(MTK_KERNEL)) {
        // Copy MTK headers
        restore_buf(fd, boot.k_hdr, sizeof(mtk_hdr));
    }
    if (access(KERNEL_FILE, R_OK) == 0) {
        size_t raw_size;
        void *raw_buf;
        mmap_ro(KERNEL_FILE, raw_buf, raw_size);
        if (!COMPRESSED_ANY(check_fmt(raw_buf, raw_size)) && COMPRESSED(boot.k_fmt)) {
            boot.hdr->kernel_size() = compress(boot.k_fmt, fd, raw_buf, raw_size);
        } else {
            boot.hdr->kernel_size() = xwrite(fd, raw_buf, raw_size);
        }
        munmap(raw_buf, raw_size);
    }

    // kernel dtb
    if (access(KER_DTB_FILE, R_OK) == 0)
        boot.hdr->kernel_size() += restore(fd, KER_DTB_FILE);
    file_align();

    // ramdisk
    off.ramdisk = lseek(fd, 0, SEEK_CUR);
    if (is_flag(MTK_RAMDISK)) {
        // Copy MTK headers
        restore_buf(fd, boot.r_hdr, sizeof(mtk_hdr));
    }
    if (access(RAMDISK_FILE, R_OK) == 0) {
        size_t raw_size;
        void *raw_buf;
        mmap_ro(RAMDISK_FILE, raw_buf, raw_size);
        if (!skip_comp && !COMPRESSED_ANY(check_fmt(raw_buf, raw_size)) && COMPRESSED(boot.r_fmt)) {
            boot.hdr->ramdisk_size() = compress(boot.r_fmt, fd, raw_buf, raw_size);
        } else {
            boot.hdr->ramdisk_size() = xwrite(fd, raw_buf, raw_size);
        }
        munmap(raw_buf, raw_size);
        file_align();
    }

    // second
    off.second = lseek(fd, 0, SEEK_CUR);
    if (access(SECOND_FILE, R_OK) == 0) {
        boot.hdr->second_size() = restore(fd, SECOND_FILE);
        file_align();
    }

    // extra
    off.extra = lseek(fd, 0, SEEK_CUR);
    if (access(EXTRA_FILE, R_OK) == 0) {
        size_t raw_size;
        void *raw_buf;
        mmap_ro(EXTRA_FILE, raw_buf, raw_size);
        if (!skip_comp && !COMPRESSED_ANY(check_fmt(raw_buf, raw_size)) && COMPRESSED(boot.e_fmt)) {
            boot.hdr->extra_size() = compress(boot.e_fmt, fd, raw_buf, raw_size);
        } else {
            boot.hdr->extra_size() = xwrite(fd, raw_buf, raw_size);
        }
        munmap(raw_buf, raw_size);
        file_align();
    }

    // recovery_dtbo
    if (access(RECV_DTBO_FILE, R_OK) == 0) {
        boot.hdr->recovery_dtbo_offset() = lseek(fd, 0, SEEK_CUR);
        boot.hdr->recovery_dtbo_size() = restore(fd, RECV_DTBO_FILE);
        file_align();
    }

    // dtb
    off.dtb = lseek(fd, 0, SEEK_CUR);
    if (access(DTB_FILE, R_OK) == 0) {
        boot.hdr->dtb_size() = restore(fd, DTB_FILE);
        file_align();
    }

    // Append tail info
    if (is_flag(SEANDROID_FLAG)) {
        restore_buf(fd, SEANDROID_MAGIC "\xFF\xFF\xFF\xFF", 20);
    }
    if (is_flag(LG_BUMP_FLAG)) {
        restore_buf(fd, LG_BUMP_MAGIC, 16);
    }

    off.total = lseek(fd, 0, SEEK_CUR);

    // Pad image to at least original size if not chromeos (as it requires post processing)
    if (!is_flag(CHROMEOS_FLAG)) {
        if (off.total < boot.map_size) {
            int padding = boot.map_size - off.total;
            write_zero(fd, padding);
        }
    }

    close(fd);

    /*********************
     * Patching the image
     *********************/

    // Map output image as rw
    munmap(boot.map_addr, boot.map_size);
    mmap_rw(out_img, boot.map_addr, boot.map_size);

    // MTK headers
    if (is_flag(MTK_KERNEL)) {
        auto hdr = reinterpret_cast<mtk_hdr *>(boot.map_addr + off.kernel);
        hdr->size = boot.hdr->kernel_size();
        boot.hdr->kernel_size() += sizeof(*hdr);
    }
    if (is_flag(MTK_RAMDISK)) {
        auto hdr = reinterpret_cast<mtk_hdr *>(boot.map_addr + off.ramdisk);
        hdr->size = boot.hdr->ramdisk_size();
        boot.hdr->ramdisk_size() += sizeof(*hdr);
    }

    // Make sure header size matches
    boot.hdr->header_size() = boot.hdr->hdr_size();

    // Update checksum
    if (char *id = boot.hdr->id()) {
        HASH_CTX ctx;
        is_flag(SHA256_FLAG) ? SHA256_init(&ctx) : SHA_init(&ctx);
        uint32_t size = boot.hdr->kernel_size();
        HASH_update(&ctx, boot.map_addr + off.kernel, size);
        HASH_update(&ctx, &size, sizeof(size));
        size = boot.hdr->ramdisk_size();
        HASH_update(&ctx, boot.map_addr + off.ramdisk, size);
        HASH_update(&ctx, &size, sizeof(size));
        size = boot.hdr->second_size();
        HASH_update(&ctx, boot.map_addr + off.second, size);
        HASH_update(&ctx, &size, sizeof(size));
        size = boot.hdr->extra_size();
        if (size) {
            HASH_update(&ctx, boot.map_addr + off.extra, size);
            HASH_update(&ctx, &size, sizeof(size));
        }
        uint32_t ver = boot.hdr->header_version();
        if (ver == 1 || ver == 2) {
            size = boot.hdr->recovery_dtbo_size();
            HASH_update(&ctx, boot.map_addr + boot.hdr->recovery_dtbo_offset(), size);
            HASH_update(&ctx, &size, sizeof(size));
        }
        if (ver == 2) {
            size = boot.hdr->dtb_size();
            HASH_update(&ctx, boot.map_addr + off.dtb, size);
            HASH_update(&ctx, &size, sizeof(size));
        }
        memset(id, 0, BOOT_ID_SIZE);
        memcpy(id, HASH_final(&ctx), is_flag(SHA256_FLAG) ? SHA256_DIGEST_SIZE : SHA_DIGEST_SIZE);
    }

    // Print new image info
    boot.hdr->print();

    // Main header
    memcpy(boot.map_addr + off.header, boot.hdr->raw_hdr(), boot.hdr->hdr_size());

    if (is_flag(DHTB_FLAG)) {
        // DHTB header
        auto hdr = reinterpret_cast<dhtb_hdr *>(boot.map_addr);
        memcpy(hdr, DHTB_MAGIC, 8);
        hdr->size = off.total - sizeof(dhtb_hdr);
        SHA256_hash(boot.map_addr + sizeof(dhtb_hdr), hdr->size, hdr->checksum);
    } else if (is_flag(BLOB_FLAG)) {
        // Blob header
        auto hdr = reinterpret_cast<blob_hdr *>(boot.map_addr);
        hdr->size = off.total - sizeof(blob_hdr);
    }
}