6ed9380b91
* Most OEMs who use MediaTek tend to ship preloader images without a header, therefore to allow preloader updates, it's necessary to create DM devices that allow writing to the physical preloader partition without the header. Change-Id: I6c3168ecabca4d4e56893d2a1bfea6a256577bd0 Signed-off-by: bengris32 <bengris32@protonmail.ch>
121 lines
3.1 KiB
C++
121 lines
3.1 KiB
C++
/*
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* SPDX-FileCopyrightText: 2024 The LineageOS Project
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define LOG_TAG "create_pl_dev"
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#include <android-base/unique_fd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <libdm/dm.h>
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#include <log/log.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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#define BLOCK_SIZE 512
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#define EMMC_HSZ 0x800
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#define UFS_HSZ 0x1000
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#define COMBO_HEADER_SIZE 4
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#define UFS_HEADER_SIZE 3
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#define UFS_HEADER "UFS"
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#define EMMC_HEADER "EMMC"
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#define COMBO_HEADER "COMB"
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using namespace android::dm;
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struct pl_device {
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const char* dm_name;
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const char* dev;
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};
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static struct pl_device pl_devices[] = {
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{"preloader_raw_a", "/dev/block/sda"},
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{"preloader_raw_b", "/dev/block/sdb"},
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{"preloader_raw_a", "/dev/block/mmcblk0boot0"},
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{"preloader_raw_b", "/dev/block/mmcblk0boot1"},
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};
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static void create_dm_device(const char* name, const char* dev, int start, int count) {
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DeviceMapper& dm = DeviceMapper::Instance();
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DmTable table;
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std::unique_ptr<DmTarget> target;
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std::string path;
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target = std::make_unique<DmTargetLinear>(0, count, dev, start);
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if (!table.AddTarget(std::move(target))) {
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ALOGE("Failed to add target for %s.", name);
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return;
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}
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if (!dm.CreateDevice(name, table, &path, std::chrono::milliseconds(500))) {
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ALOGE("Failed to create device %s.", name);
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return;
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}
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ALOGI("Created DM device %s at %s.", name, path.c_str());
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}
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int main() {
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int fd, size, count, start;
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char header[COMBO_HEADER_SIZE];
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for (int i = 0; i < sizeof(pl_devices) / sizeof(pl_device); i++) {
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pl_device* device = &pl_devices[i];
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if (access(device->dev, F_OK) == -1) {
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ALOGE("Device %s not found.", device->dev);
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continue;
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}
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fd = open(device->dev, O_RDONLY);
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if (fd == -1) {
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ALOGE("Failed to open %s: %s.", device->dev, strerror(errno));
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continue;
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}
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size = lseek(fd, 0, SEEK_END);
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if (size == -1) {
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ALOGE("Failed to seek %s: %s.", device->dev, strerror(errno));
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close(fd);
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continue;
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}
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count = size / BLOCK_SIZE;
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if (lseek(fd, 0, SEEK_SET) == -1) {
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ALOGE("Failed to seek %s: %s.", device->dev, strerror(errno));
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close(fd);
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continue;
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}
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if (read(fd, header, COMBO_HEADER_SIZE) != COMBO_HEADER_SIZE) {
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ALOGE("Failed to read %s: %s.", device->dev, strerror(errno));
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close(fd);
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continue;
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}
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close(fd);
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if (strncmp(header, UFS_HEADER, UFS_HEADER_SIZE) == 0 ||
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strncmp(header, COMBO_HEADER, COMBO_HEADER_SIZE) == 0) {
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start = UFS_HSZ / BLOCK_SIZE;
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} else if (strncmp(header, EMMC_HEADER, COMBO_HEADER_SIZE) == 0) {
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start = EMMC_HSZ / BLOCK_SIZE;
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} else {
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ALOGE("Unknown header %s for %s.", header, device->dev);
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continue;
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}
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count -= start;
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create_dm_device(device->dm_name, device->dev, start, count);
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}
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return 0;
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}
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