kupferbootstrap/image/flash.py

import shutil
import os
import click
import logging

from typing import Optional

from constants import FLASH_PARTS, LOCATIONS, FASTBOOT, JUMPDRIVE
from exec.cmd import run_root_cmd
from exec.file import get_temp_dir
from devices.device import get_profile_device
from flavours.flavour import get_profile_flavour
from flavours.cli import profile_option
from wrapper import enforce_wrap

from .fastboot import fastboot_flash
from .image import dd_image, dump_aboot, dump_lk2nd, dump_qhypstub, get_image_path, losetup_destroy, losetup_rootfs_image, partprobe, shrink_fs

ABOOT = FLASH_PARTS['ABOOT']
LK2ND = FLASH_PARTS['LK2ND']
QHYPSTUB = FLASH_PARTS['QHYPSTUB']
FULL_IMG = FLASH_PARTS['FULL']

DD = 'dd'

FLASH_METHODS = [FASTBOOT, JUMPDRIVE, DD]


def find_jumpdrive(location: str) -> str:
    if location not in LOCATIONS:
        raise Exception(f'Invalid location {location}. Choose one of {", ".join(LOCATIONS)}')
    dir = '/dev/disk/by-id'
    for file in os.listdir(dir):
        sanitized_file = file.replace('-', '').replace('_', '').lower()
        if f'jumpdrive{location.split("-")[0]}' in sanitized_file:
            return os.path.realpath(os.path.join(dir, file))
    raise Exception('Unable to discover Jumpdrive')


def test_blockdev(path: str):
    partprobe(path)
    result = run_root_cmd(['lsblk', path, '-o', 'SIZE'], capture_output=True)
    if result.returncode != 0:
        raise Exception(f'Failed to lsblk {path}')
    if result.stdout == b'SIZE\n  0B\n':
        raise Exception(f'Disk {path} has a size of 0B. That probably means it is not available (e.g. no'
                        'microSD inserted or no microSD card slot installed in the device) or corrupt or defect')


def prepare_minimal_image(source_path: str, sector_size: int) -> str:
    minimal_image_dir = get_temp_dir(register_cleanup=True)
    minimal_image_path = os.path.join(minimal_image_dir, f'minimal-{os.path.basename(source_path)}')
    logging.info(f"Copying image {os.path.basename(source_path)} to {minimal_image_dir} for shrinking")
    shutil.copyfile(source_path, minimal_image_path)

    loop_device = losetup_rootfs_image(minimal_image_path, sector_size)
    partprobe(loop_device)
    shrink_fs(loop_device, minimal_image_path, sector_size)
    losetup_destroy(loop_device)
    return minimal_image_path


@click.command(name='flash')
@profile_option
@click.option('-m', '--method', type=click.Choice(FLASH_METHODS))
@click.option('--split-size', help='Chunk size when splitting the image into sparse files via fastboot')
@click.option('--shrink/--no-shrink', is_flag=True, default=True, help="Copy and shrink the image file to minimal size")
@click.option('-b', '--sector-size', type=int, help="Override the device's sector size", default=None)
@click.option('--confirm', is_flag=True, help="Ask for confirmation before executing fastboot commands")
@click.argument('what', type=click.Choice(list(FLASH_PARTS.values())))
@click.argument('location', type=str, required=False)
def cmd_flash(
    what: str,
    location: str,
    method: Optional[str] = None,
    split_size: Optional[str] = None,
    profile: Optional[str] = None,
    shrink: bool = True,
    sector_size: Optional[int] = None,
    confirm: bool = False,
):
    """
    Flash a partition onto a device.

    The syntax of LOCATION depends on the flashing method and is usually only required for flashing "full":

    \b
    - fastboot: the regular fastboot partition identifier. Usually "userdata"
    - dd: a path to a block device
    - jumpdrive: one of "emmc", "sdcard" or a path to a block device
    """
    enforce_wrap()
    device = get_profile_device(profile)
    flavour = get_profile_flavour(profile).name
    device_image_path = get_image_path(device, flavour)

    deviceinfo = device.parse_deviceinfo()
    sector_size = sector_size or device.get_image_sectorsize_default()
    method = method or deviceinfo.flash_method

    if what not in FLASH_PARTS.values():
        raise Exception(f'Unknown what "{what}", must be one of {", ".join(FLASH_PARTS.values())}')

    if location and location.startswith('aboot'):
        raise Exception("You're trying to flash something "
                        f"to your aboot partition ({location!r}), "
                        "which contains the android bootloader itself.\n"
                        "This will brick your phone and is not what you want.\n"
                        'Aborting.\nDid you mean to flash to "boot"?')

    if what == FULL_IMG:
        path = ''
        if method not in FLASH_METHODS:
            raise Exception(f"Flash method {method} not supported!")
        if not location:
            raise Exception(f'You need to specify a location to flash {what} to')
        path = ''
        image_path = prepare_minimal_image(device_image_path, sector_size) if shrink else device_image_path
        if method == FASTBOOT:
            fastboot_flash(
                partition=location,
                file=image_path,
                sparse_size=split_size if split_size is not None else '100M',
                confirm=confirm,
            )
        elif method in [JUMPDRIVE, DD]:
            if method == DD or location.startswith("/") or (location not in LOCATIONS and os.path.exists(location)):
                path = location
            elif method == JUMPDRIVE:
                path = find_jumpdrive(location)
            test_blockdev(path)
            if dd_image(input=image_path, output=path).returncode != 0:
                raise Exception(f'Failed to flash {image_path} to {path}')
        else:
            raise Exception(f'Unhandled flash method "{method}" for "{what}"')
    else:
        if method and method != FASTBOOT:
            raise Exception(f'Flashing "{what}" with method "{method}" not supported, try no parameter or "{FASTBOOT}"')
        loop_device = losetup_rootfs_image(device_image_path, sector_size)
        if what == ABOOT:
            path = dump_aboot(f'{loop_device}p1')
            fastboot_flash(location or 'boot', path, confirm=confirm)
        elif what == LK2ND:
            path = dump_lk2nd(f'{loop_device}p1')
            fastboot_flash(location or 'lk2nd', path, confirm=confirm)
        elif what == QHYPSTUB:
            path = dump_qhypstub(f'{loop_device}p1')
            fastboot_flash(location or 'qhypstub', path, confirm=confirm)
        else:
            raise Exception(f'Unknown what "{what}", this must be a bug in kupferbootstrap!')