.. SPDX-License-Identifier: GPL-2.0+: bootflow command ================ Synopis ------- :: bootflow scan [-abelGH] [bootdev] bootflow list [-e] bootflow select [] bootflow info [-d] bootflow boot Description ----------- The `bootflow` command is used to manage bootflows. It can scan bootdevs to locate bootflows, list them and boot them. See :doc:`../../develop/bootstd` for more information. bootflow scan ~~~~~~~~~~~~~ Scans for available bootflows, optionally booting the first valid one it finds. This operates in two modes: - If no bootdev is selected (see `bootdev select`) it scans bootflows one by one, extracting all the bootdevs from each - If a bootdev is selected, it just scans that one bootflow Flags are: -a Collect all bootflows, even those that cannot be loaded. Normally if a file is not where it is expected, then the bootflow fails and so is dropped during the scan. With this option you can see why each bootflow would be dropped. -b Boot each valid bootflow as it is scanned. Typically only the first bootflow matters, since by then the system boots in the OS and U-Boot is no-longer running. `bootflow scan -b` is a quick way to boot the first available OS. A valid bootflow is one that made it all the way to the `loaded` state. -e Used with -l to also show errors for each bootflow. The shows detailed error information for each bootflow that failed to make it to the `loaded` state. -l List bootflows while scanning. This is helpful when you want to see what is happening during scanning. Use it with the `-b` flag to see which bootdev and bootflows are being tried. -G Skip global bootmeths when scanning. By default these are tried first, but this flag disables them. -H Don't use bootdev hunters. By default these are used before each boot priority or label is tried, to see if more bootdevs can be discovered, but this flag disables that process. The optional argument specifies a particular bootdev to scan. This can either be the name of a bootdev or its sequence number (both shown with `bootdev list`). Alternatively a convenience label can be used, like `mmc0`, which is the type of device and an optional sequence number. Specifically, the label is the uclass of the bootdev's parent followed by the sequence number of that parent. Sequence numbers are typically set by aliases, so if you have 'mmc0' in your devicetree alias section, then `mmc0` refers to the bootdev attached to that device. bootflow list ~~~~~~~~~~~~~ Lists the previously scanned bootflows. You must use `bootflow scan` before this to see anything. If you scanned with -a and have bootflows with errors, -e can be used to show those errors. The list looks something like this: === ====== ====== ======== ==== =============================== ================ Seq Method State Uclass Part Name Filename === ====== ====== ======== ==== =============================== ================ 0 distro ready mmc 2 mmc\@7e202000.bootdev.part_2 /boot/extlinux/extlinux.conf 1 pxe ready ethernet 0 smsc95xx_eth.bootdev.0 rpi.pxe/extlinux/extlinux.conf === ====== ====== ======== ==== =============================== ================ The fields are as follows: Seq: Sequence number in the scan, used to reference the bootflow later Method: The boot method (bootmeth) used to find the bootflow. Several methods are included in U-Boot. State: Current state of the bootflow, indicating how far the bootdev got in obtaining a valid one. See :ref:`BootflowStates` for a list of states. Uclass: Name of the media device's Uclass. This indicates the type of the parent device (e.g. MMC, Ethernet). Part: Partition number being accesseed, numbered from 1. Normally a device will have a partition table with a small number of partitions. For devices without partition tables (e.g. network) this field is 0. Name: Name of the bootflow. This is generated from the bootdev appended with the partition information Filename: Name of the bootflow file. This indicates where the file is on the filesystem or network device. bootflow select ~~~~~~~~~~~~~~~ Use this to select a particular bootflow. You can select it by the sequence number or name, as shown in `bootflow list`. Once a bootflow is selected, you can use `bootflow info` and `bootflow boot`. If no bootflow name or number is provided, then any existing bootflow is unselected. bootflow info ~~~~~~~~~~~~~ This shows information on the current bootflow, with the format looking like this: ========= =============================== Name mmc\@7e202000.bootdev.part_2 Device mmc\@7e202000.bootdev Block dev mmc\@7e202000.blk Type distro Method: syslinux State ready Partition 2 Subdir (none) Filename /extlinux/extlinux.conf Buffer 3db7ad48 Size 232 (562 bytes) FDT: Error 0 ========= =============================== Most of the information is the same as `bootflow list` above. The new fields are: Device Name of the bootdev Block dev Name of the block device, if any. Network devices don't have a block device. Subdir Subdirectory used for retrieving files. For network bootdevs this is the directory of the 'bootfile' parameter passed from DHCP. All file retrievals when booting are relative to this. Buffer Buffer containing the bootflow file. You can use the :doc:`md` to look at it, or dump it with `bootflow info -d`. Size Size of the bootflow file FDT: Filename of the device tree, if supported. The EFI bootmeth uses this to remember the filename to load. If `` then there is none. Error Error number returned from scanning for the bootflow. This is 0 if the bootflow is in the 'loaded' state, or a negative error value on error. You can look up Linux error codes to find the meaning of the number. Use the `-d` flag to dump out the contents of the bootfile file. bootflow boot ~~~~~~~~~~~~~ This boots the current bootflow. Example ------- Here is an example of scanning for bootflows, then listing them:: U-Boot> bootflow scan -l Scanning for bootflows in all bootdevs Seq Type State Uclass Part Name Filename --- ----------- ------ -------- ---- ------------------------ ---------------- Scanning bootdev 'mmc@7e202000.bootdev': 0 distro ready mmc 2 mmc@7e202000.bootdev.p /extlinux/extlinux.conf Scanning bootdev 'sdhci@7e300000.bootdev': Card did not respond to voltage select! : -110 Scanning bootdev 'smsc95xx_eth.bootdev': Waiting for Ethernet connection... done. BOOTP broadcast 1 DHCP client bound to address 192.168.4.30 (4 ms) Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe/'. Load address: 0x200000 Loading: * TFTP error: 'Is a directory' (0) Starting again missing environment variable: pxeuuid Retrieving file: rpi.pxe/pxelinux.cfg/01-b8-27-eb-a6-61-e1 Waiting for Ethernet connection... done. Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe/pxelinux.cfg/01-b8-27-eb-a6-61-e1'. Load address: 0x2500000 Loading: ################################################## 566 Bytes 45.9 KiB/s done Bytes transferred = 566 (236 hex) 1 distro ready ethernet 0 smsc95xx_eth.bootdev.0 rpi.pxe/extlinux/extlinux.conf No more bootdevs --- ----------- ------ -------- ---- ------------------------ ---------------- (2 bootflows, 2 valid) U-Boot> bootflow l Showing all bootflows Seq Type State Uclass Part Name Filename --- ----------- ------ -------- ---- ------------------------ ---------------- 0 distro ready mmc 2 mmc@7e202000.bootdev.p /extlinux/extlinux.conf 1 pxe ready ethernet 0 smsc95xx_eth.bootdev.0 rpi.pxe/extlinux/extlinux.conf --- ----------- ------ -------- ---- ------------------------ ---------------- (2 bootflows, 2 valid) The second one is then selected by name (we could instead use `bootflow sel 0`), displayed and booted:: U-Boot> bootflow info No bootflow selected U-Boot> bootflow sel mmc@7e202000.bootdev.part_2 U-Boot> bootflow info Name: mmc@7e202000.bootdev.part_2 Device: mmc@7e202000.bootdev Block dev: mmc@7e202000.blk Sequence: 1 Method: distro State: ready Partition: 2 Subdir: (none) Filename: extlinux/extlinux.conf Buffer: 3db7ae88 Size: 232 (562 bytes) Error: 0 U-Boot> bootflow boot ** Booting bootflow 'smsc95xx_eth.bootdev.0' Ignoring unknown command: ui Ignoring malformed menu command: autoboot Ignoring malformed menu command: hidden Ignoring unknown command: totaltimeout 1: Fedora-Workstation-armhfp-31-1.9 (5.3.7-301.fc31.armv7hl) Retrieving file: rpi.pxe/initramfs-5.3.7-301.fc31.armv7hl.img get 2700000 rpi.pxe/initramfs-5.3.7-301.fc31.armv7hl.img Waiting for Ethernet connection... done. Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe/initramfs-5.3.7-301.fc31.armv7hl.img'. Load address: 0x2700000 Loading: ###################################T ############### 57.7 MiB 1.9 MiB/s done Bytes transferred = 60498594 (39b22a2 hex) Retrieving file: rpi.pxe//vmlinuz-5.3.7-301.fc31.armv7hl get 80000 rpi.pxe//vmlinuz-5.3.7-301.fc31.armv7hl Waiting for Ethernet connection... done. Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe//vmlinuz-5.3.7-301.fc31.armv7hl'. Load address: 0x80000 Loading: ################################################## 7.2 MiB 2.3 MiB/s done Bytes transferred = 7508480 (729200 hex) append: ro root=UUID=9732b35b-4cd5-458b-9b91-80f7047e0b8a rhgb quiet LANG=en_US.UTF-8 cma=192MB cma=256MB Retrieving file: rpi.pxe//dtb-5.3.7-301.fc31.armv7hl/bcm2837-rpi-3-b.dtb get 2600000 rpi.pxe//dtb-5.3.7-301.fc31.armv7hl/bcm2837-rpi-3-b.dtb Waiting for Ethernet connection... done. Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe//dtb-5.3.7-301.fc31.armv7hl/bcm2837-rpi-3-b.dtb'. Load address: 0x2600000 Loading: ################################################## 13.8 KiB 764.6 KiB/s done Bytes transferred = 14102 (3716 hex) Kernel image @ 0x080000 [ 0x000000 - 0x729200 ] ## Flattened Device Tree blob at 02600000 Booting using the fdt blob at 0x2600000 Using Device Tree in place at 02600000, end 02606715 Starting kernel ... [ OK ] Started Show Plymouth Boot Screen. [ OK ] Started Forward Password R…s to Plymouth Directory Watch. [ OK ] Reached target Local Encrypted Volumes. [ OK ] Reached target Paths. .... Here we scan for bootflows and boot the first one found:: U-Boot> bootflow scan -bl Scanning for bootflows in all bootdevs Seq Method State Uclass Part Name Filename --- ----------- ------ -------- ---- ---------------------- ---------------- Scanning bootdev 'mmc@7e202000.bootdev': 0 distro ready mmc 2 mmc@7e202000.bootdev.p /extlinux/extlinux.conf ** Booting bootflow 'mmc@7e202000.bootdev.part_2' Ignoring unknown command: ui Ignoring malformed menu command: autoboot Ignoring malformed menu command: hidden Ignoring unknown command: totaltimeout 1: Fedora-KDE-armhfp-31-1.9 (5.3.7-301.fc31.armv7hl) Retrieving file: /initramfs-5.3.7-301.fc31.armv7hl.img getfile 2700000 /initramfs-5.3.7-301.fc31.armv7hl.img Retrieving file: /vmlinuz-5.3.7-301.fc31.armv7hl getfile 80000 /vmlinuz-5.3.7-301.fc31.armv7hl append: ro root=UUID=b8781f09-e2dd-4cb8-979b-7df5eeaaabea rhgb LANG=en_US.UTF-8 cma=192MB console=tty0 console=ttyS1,115200 Retrieving file: /dtb-5.3.7-301.fc31.armv7hl/bcm2837-rpi-3-b.dtb getfile 2600000 /dtb-5.3.7-301.fc31.armv7hl/bcm2837-rpi-3-b.dtb Kernel image @ 0x080000 [ 0x000000 - 0x729200 ] ## Flattened Device Tree blob at 02600000 Booting using the fdt blob at 0x2600000 Using Device Tree in place at 02600000, end 02606715 Starting kernel ... [ 0.000000] Booting Linux on physical CPU 0x0 Here is am example using the -e flag to see all errors:: U-Boot> bootflow scan -a Card did not respond to voltage select! : -110 Waiting for Ethernet connection... done. BOOTP broadcast 1 DHCP client bound to address 192.168.4.30 (4 ms) Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe/'. Load address: 0x200000 Loading: * TFTP error: 'Is a directory' (0) Starting again missing environment variable: pxeuuid Retrieving file: rpi.pxe/pxelinux.cfg/01-b8-27-eb-a6-61-e1 Waiting for Ethernet connection... done. Using smsc95xx_eth device TFTP from server 192.168.4.1; our IP address is 192.168.4.30 Filename 'rpi.pxe/pxelinux.cfg/01-b8-27-eb-a6-61-e1'. Load address: 0x2500000 Loading: ################################################## 566 Bytes 49.8 KiB/s done Bytes transferred = 566 (236 hex) U-Boot> bootflow l -e Showing all bootflows Seq Type State Uclass Part Name Filename --- ----------- ------ -------- ---- --------------------- ---------------- 0 distro fs mmc 1 mmc@7e202000.bootdev.p /extlinux/extlinux.conf ** File not found, err=-2 1 distro ready mmc 2 mmc@7e202000.bootdev.p /extlinux/extlinux.conf 2 distro fs mmc 3 mmc@7e202000.bootdev.p /extlinux/extlinux.conf ** File not found, err=-1 3 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 4 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 5 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 6 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 7 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 8 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 9 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 a distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 b distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 c distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 d distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 e distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 f distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 10 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 11 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 12 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 13 distro media mmc 0 mmc@7e202000.bootdev.p ** No partition found, err=-2 14 distro ready ethernet 0 smsc95xx_eth.bootdev.0 rpi.pxe/extlinux/extlinux.conf --- ----------- ------ -------- ---- --------------------- ---------------- (21 bootflows, 2 valid) U-Boot> Return value ------------ On success `bootflow boot` normally boots into the Operating System and does not return to U-Boot. If something about the U-Boot processing fails, then the return value $? is 1. If the boot succeeds but for some reason the Operating System returns, then $? is 0, indicating success. For other subcommands, the return value $? is always 0 (true). .. BootflowStates_: