[PATCH v2 1/2] Add support for extlinux.conf

[Alexander Shiyan]

Hello Ahmad.

barebox at Diasom DS-RK3568-SOM-EVB:/ global
* allow_color: 1
  arch: arm64
  autoboot: countdown (values: "countdown", "abort", "halt", "menu", "boot")
  autoboot_abort_key: <NULL>
* autoboot_timeout: 2
* boot.default: default
  boot.watchdog_timeout: 0
  bootm.appendroot: 0
  bootm.dryrun: 0
  bootm.earlycon: 0
  bootm.image:
  bootm.image.loadaddr:
  bootm.initrd:
  bootm.initrd.loadaddr:
  bootm.oftree:
  bootm.provide_hostname: 0
* bootm.provide_machine_id: 1
  bootm.root_dev:
  bootm.root_param: root
  bootm.tee:
  bootm.verbose: 0
  bootm.verify: available (values: "none", "hash", "signature", "available")
* bootm.~appendroot: true
  console.ctrlc_allowed: 1
  dhcp.bootfile:
  dhcp.client_id:
  dhcp.client_uuid:
  dhcp.hostname:
  dhcp.oftree_file:
  dhcp.option224:
  dhcp.retries: 20
  dhcp.rootpath:
  dhcp.tftp_server_name:
  dhcp.user_class:
  dhcp.vendor_id: barebox
  endianness: little
  env.autoprobe: 1
  fastboot.bbu: 0
  fastboot.max_download_size: 134217728
  fastboot.partitions:
  firmware.path: /env/firmware
  hostname: diasom
  linux.bootargs.base:
  linux.bootargs.console: console=ttyS2,1500000n8
  linux.bootargs_append: 0
  linux.rootnfsopts: v3,tcp
  log_max_messages: 32768
  loglevel: 7
  machine_id: 181af2816b4c6b0aef77068e0ccc69ad
  model: Diasom DS-RK3568-SOM-EVB
  net.domainname:
  net.fetchdir: /mnt/tftp
  net.gateway: 0.0.0.0
  net.ifup_force_detect: 0
  net.nameserver: 0.0.0.0
  net.server:
  nfs.port: 0
  of.kernel.add_machine_compatible:
  of.overlay.compatible:
  of.overlay.filter: pattern compatible
  of.overlay.path:
  of.overlay.pattern: *
  of_partition_binding: adaptive (values: "new", "legacy",
"donttouch", "adaptive")
  partitions.first_usable_lba: 16384
  system.partitions:
  system.reset: unknown (values: "unknown", "POR", "RST", "WDG",
"WKE", "JTAG", "THERM", "EXT", "BROWNOUT")
  system.reset_instance: 0
  tftp.windowsize: 1
  usbgadget.acm: 0
  usbgadget.dfu_function:
* user: none
  version: 2026.04.0-00765-gd3f78fc00c40-dirty
barebox at Diasom DS-RK3568-SOM-EVB:/ global.boot.default=mmc1.2
barebox at Diasom DS-RK3568-SOM-EVB:/ boot -d
ext4 ext40: EXT2 rev 1, inode_size 256, descriptor size 64
Booting entry 'extlinux: linux'
extlinux: Booting extlinux label 'linux'

Loading ARM aarch64 Linux/EFI image '/mnt/mmc1.2/boot/extlinux/../vmlinuz'
Camera IMX662 detected.
commandline: console=ttyS2,1500000n8
systemd.machine_id=181af2816b4c6b0aef77068e0ccc69ad root=LABEL=ROOT ro
systemd.unit=setup.target quiet splash
Loaded kernel to 0x0a400000, devicetree at 0x000000000fb49000
Dryrun. Aborted

bootm.~appendroot: true, but now is ever not added to the cmdline.

вт, 5 мая 2026 г. в 13:49, Ahmad Fatoum <a.fatoum at pengutronix.de>:
>
> Hello Alexander,
>
> On 5/5/26 12:47 PM, Alexander Shiyan wrote:
> > Hello Ahmad.
> >
> > ...
> >>> +     if (e->append) {
> >>> +             char *append;
> >>> +
> >>> +             /*
> >>> +              * The same rootfs image may be launched from eMMC or SD card.
> >>> +              * Remove any hardcoded root= parameter from "append" to avoid
> >>> +              * conflicts, then let barebox automatically add the correct
> >>> +              * root= (via global.bootm.appendroot) based on the boot device.
> >>> +              */
> >>> +             if (data.appendroot)
> >>> +                     append = remove_param(e->append, "ROOT=");
> > ...
> >> I thus have a question to you: What happens if you drop remove_param()
> >> completely? Sure we will have two root=, but the later gets precedence,
> >> so your use case would continue to work without giving users a wrong
> >> expectation.
> >
> > Yes, the second one takes priority.
> > The second one is the one added via extlinux.conf APPEND option.
> > In our case we need the first parameter, i.e. which comes from barebox
> > when global.bootm.appendroot is toggled on.
>
> Ack. Please check the series I Cc'd you on, which ensures that
> global.bootm.appendroot applies _after_ extlinux.conf APPEND.
>
> Thanks,
> Ahmad
>
> >
> > Thanks!
> >
>
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