--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pi-setup/setup_pi.py	Sun Apr 14 20:54:35 2024 -0700
@@ -0,0 +1,260 @@
+import asyncio
+import logging
+import re
+import sys
+import time
+from pathlib import Path
+from functools import wraps
+from runner import get_output, iscsi_login, mount, run, sshfs
+
+logging.basicConfig(level=logging.INFO, format='%(asctime)s.%(msecs)03d %(levelname)s %(filename) 12s:%(lineno)d %(message)s', datefmt='%H:%M:%S')
+log = logging.getLogger()
+
+WORK = Path('/tmp/pi-setup')
+LITE_PREFIX = '2024-03-15-raspios-bookworm'
+
+# These come from fdisk -l on the img:
+IMG_BOOT_OFFSET = 512 * 8192
+IMG_ROOT_OFFSET = 512 * 1056768
+
+TFTP_SPEC = 'root@pipe:/opt/dnsmasq/tftp/'
+
+
+def step(func):
+    name = func.__name__
+
+    @wraps(func)
+    async def wrapper(*a, **kw):
+        print("", file=sys.stderr)
+        log.info(f'👣 step {name}')
+        t1 = time.time()
+        ret = await func(*a, **kw)
+        dt = time.time() - t1
+        log.info(f' -> step {name} took {dt:3} seconds')
+        return ret
+
+    return wrapper
+
+
+@step
+async def init_work_dir():
+    WORK.mkdir(exist_ok=True)
+    await run(
+        'wget', '--continue', '--no-verbose', '-O', WORK / 'raspios.img.xz',
+        f'https://downloads.raspberrypi.org/raspios_lite_arm64/images/raspios_lite_arm64-2024-03-15/{LITE_PREFIX}-arm64-lite.img.xz'
+    )
+
+
+@step
+async def unpack_fresh_img_copy():
+    await run('xz', '-dkf', WORK / 'raspios.img.xz')
+    await run('qemu-img', 'resize', ['-f', 'raw'], WORK / 'raspios.img', '4G')
+
+
+@step
+async def extract_boot_files():
+    async with mount(WORK, WORK / 'raspios.img', IMG_BOOT_OFFSET) as img_boot:
+        await run('cp', img_boot / 'bcm2710-rpi-3-b-plus.dtb', WORK)
+        await run('cp', img_boot / 'kernel8.img', WORK)
+
+
+@step
+async def setup_ssh_login():
+    async with mount(WORK, WORK / 'raspios.img', IMG_ROOT_OFFSET) as img_root:
+        root_pub_key = Path('/root/.ssh/id_ecdsa.pub').read_text()
+        (img_root / 'root/.ssh/authorized_keys').write_text(root_pub_key)
+        # (img_root / 'etc/iscsi/initiatorname.iscsi').write_text(f"InitiatorName=iqn.2024-03.com.bigasterisk:{PI_HOSTNAME}\n")
+
+    async with mount(WORK, WORK / 'raspios.img', IMG_BOOT_OFFSET) as img_boot:
+        await run('touch', img_boot / 'ssh')
+
+
+@step
+async def qemu():
+    await run(
+        'qemu-system-aarch64',
+        ['-machine', 'raspi3b'],
+        ['-cpu', 'cortex-a72'],
+        ['-nographic'],
+        ['-dtb', WORK / 'bcm2710-rpi-3-b-plus.dtb'],
+        ['-m', '1G'],
+        ['-smp', '4'],
+        ['-kernel', WORK / 'kernel8.img'],
+        ['-sd', WORK / 'raspios.img'],
+        ['-append', "rw earlyprintk loglevel=8 console=ttyAMA0,115200 dwc_otg.lpm_enable=0 root=/dev/mmcblk0p2 rootdelay=1"],
+        ['-device', 'usb-net,netdev=net0'],
+        ['-netdev', 'user,id=net0,hostfwd=tcp::2222-:22'],
+    )
+
+
+@step
+async def setup_pi_in_emulator():
+    src_path = Path(__file__).parent / 'on_pi_setup.sh'
+    path_on_pi = '/tmp/on_pi_setup.sh'
+
+    ssh_opts = [
+        '-oPort=2222',
+        '-oConnectTimeout=2',
+        '-oBatchMode=yes',
+        '-oNoHostAuthenticationForLocalHost=yes',
+    ]
+    give_up = time.time() + 60
+    final_err = ValueError("timed out")
+    while time.time() < give_up:
+        try:
+            await run('scp', ssh_opts, src_path, f'root@localhost:{path_on_pi}')
+        except ValueError as err:
+            final_err = err
+            log.info('waiting for qemu to boot...')
+            await asyncio.sleep(8)
+            continue
+        break
+    else:
+        raise final_err
+
+    cmd_on_pi = ['sh', path_on_pi, PI_HOSTNAME]
+    await run('ssh', ssh_opts, 'root@localhost', *cmd_on_pi)
+
+
+async def _get_iscsi_device(better_be_the_iscsi_device='sde') -> Path:
+    # don't screw up- this device is about to get formatted!
+    dev_path = Path(f'/dev/{better_be_the_iscsi_device}')
+
+    iscsi = await get_output('iscsiadm', '-m', 'session', '-P3')
+    for m in re.findall(r'Attached scsi disk (\S+)', iscsi):
+        if f'/dev/{m}' != str(dev_path):
+            raise ValueError(f'surprised by attached iscsi disk {m!r} (try `iscsiadm -m node --logoutall=all`)')
+
+    fdisk = await get_output('fdisk', '-l', dev_path)
+    for m in re.findall(r'Disk model: (\S+)', fdisk):
+        if m != 'VIRTUAL-DISK':
+            raise ValueError(f'surprised that {dev_path} is model {m!r} instead of "VIRTUAL-DISK"')
+
+    return dev_path
+
+
+@step
+async def fs_to_iscsi():
+    async with mount(WORK, WORK / 'raspios.img', IMG_ROOT_OFFSET) as img_root:
+        async with iscsi_login('-m', 'node', '-T', f'iqn.2024-03.com.bigasterisk:{PI_HOSTNAME}.target', '-p', '10.2.0.133'):
+            dev = await _get_iscsi_device()
+            await run('mkfs.ext4', '-F', dev)
+            async with mount(WORK, dev, 0) as iscsi_root:
+                await run(
+                    'rsync',
+                    '-r', # recurs
+                    '-l', # symlinks as symlinks
+                    '-p', # perms
+                    '-t', # mtimes
+                    '-g', # group
+                    '-o', # owner
+                    '-D', # devices + specials
+                    '-H', # hard links
+                    ['--exclude', '/boot'],
+                    ['--exclude', '/dev'],
+                    ['--exclude', '/mnt'],
+                    ['--exclude', '/proc'],
+                    ['--exclude', '/sys'],
+                    str(img_root) + '/',
+                    str(iscsi_root) + '/',
+                )
+                for d in [
+                        'boot',
+                        'dev',
+                        'mnt',
+                        'proc',
+                        'sys',
+                ]:
+                    (iscsi_root / d).mkdir()
+                (iscsi_root / 'etc/fstab').write_text('''
+proc            /proc           proc    defaults          0       0
+/dev/sda        /               ext4    defaults,noatime  0       1
+''')
+                # don't open cursesui for making first user
+                (iscsi_root / 'etc/systemd/system/multi-user.target.wants/userconfig.service').unlink()
+                log.info("there may be a delay here for flushing all the new files")
+
+
+@step
+async def setup_tftp():
+    async with sshfs(WORK, TFTP_SPEC) as tftp:
+        tftp_host_dir = tftp / f'{PI_HOSTNAME}-boot'
+        async with mount(WORK, WORK / 'raspios.img', IMG_ROOT_OFFSET) as img_root:
+            await run(
+                'rsync',
+                    '-r', # recurs
+                    '-l', # symlinks as symlinks
+                    '-p', # perms
+                    #'-t', # mtimes
+                    '-g', # group
+                    '-o', # owner
+                    '-D', # devices + specials
+                    #'-H', # hard links
+                '--delete',
+                str(img_root) + '/boot/',
+                str(tftp_host_dir) + '/',
+            )
+        async with mount(WORK, WORK / 'raspios.img', IMG_BOOT_OFFSET) as img_boot:
+            await run(
+                'rsync',
+                    '-r', # recurs
+                    '-l', # symlinks as symlinks
+                    '-p', # perms
+                    '-t', # mtimes
+                    '-g', # group
+                    '-o', # owner
+                    '-D', # devices + specials
+                    '-H', # hard links
+                # (no delete)
+                str(img_boot) + '/',
+                str(tftp_host_dir) + '/firmware/',
+            )
+        await run('ln', '-sf', f'{PI_HOSTNAME}-boot/firmware/', str(tftp / PI_SERIAL))
+        kernel_cmdline = [
+            "console=serial0,115200",
+            "console=tty1",
+            f"ip=::::{PI_HOSTNAME}:eth0:dhcp",
+            "root=/dev/sda",
+            f"ISCSI_INITIATOR=iqn.2024-03.com.bigasterisk:{PI_HOSTNAME}.initiator",
+            f"ISCSI_TARGET_NAME=iqn.2024-03.com.bigasterisk:{PI_HOSTNAME}.target",
+            "ISCSI_TARGET_IP=10.2.0.133",
+            "ISCSI_TARGET_PORT=3260",
+            "rw",
+            "rootfstype=ext4",
+            "fsck.repair=yes",
+            "rootwait",
+            "cgroup_enable=cpuset",
+            "cgroup_memory=1",
+            "cgroup_enable=memory",
+        ]
+        (tftp_host_dir/'firmware/cmdline.txt').write_text(' '.join(kernel_cmdline))
+
+
+async def main():
+    global PI_HOSTNAME, PI_SERIAL
+
+    if sys.argv[1:] == ['--init']:
+        await init_work_dir()
+    else:
+        PI_HOSTNAME, PI_SERIAL = sys.argv[1:]
+        # todo: dd and add iscsi volume (handled by pyinfra)
+        #   dd if=/dev/zero of={out} count=0 bs=1 seek=5G conv=excl || true
+        #   edit /etc/tgt/conf.d/{pi_hostname}.conf etc
+
+        await unpack_fresh_img_copy()
+        await extract_boot_files()
+        await setup_ssh_login()
+
+        qemu_task = asyncio.create_task(qemu())
+        await asyncio.sleep(20)  # inital qemu startup delay
+        await setup_pi_in_emulator()  # finishes with a poweroff
+        log.info('waiting for qemu to exit')
+        await qemu_task
+
+        await fs_to_iscsi()
+        await setup_tftp()
+
+        log.info(f'🎉 {PI_HOSTNAME} is ready for net boot')
+
+
+asyncio.run(main())