diff options
| author | Svyatoslav Ryhel <[email protected]> | 2024-01-25 22:16:54 +0200 |
|---|---|---|
| committer | Tom Rini <[email protected]> | 2024-03-01 18:34:08 -0500 |
| commit | c95e948870bdfc606946174facd9ea359ce84e58 (patch) | |
| tree | 53c1617a12e543645c87a392d8a4734f3dae2e1d /doc/develop | |
| parent | 172e32add3d0332073538412c8d3b788e91b4d9c (diff) | |
boot: pxe_utils: skip fdt setup in case legacy kernel is booted
Currently, if boot with extlinux.conf and do not set the fdt
U-Boot will provide its own device tree. This behavior is
beneficial if the U-Boot device tree is in sync with Linux,
but it totally halts the booting of pre-dtb kernels (3.4 for
example) since it uses ATAGs. To fix this, pass `-` in the
fdt extlinux field as a signal that no tree should be used.
Suggested-by: Jonas Schwöbel <[email protected]>
Tested-by: Jethro Bull <[email protected]>
Signed-off-by: Svyatoslav Ryhel <[email protected]>
Diffstat (limited to 'doc/develop')
| -rw-r--r-- | doc/develop/distro.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/doc/develop/distro.rst b/doc/develop/distro.rst index 8016acad098..9e715b23ebb 100644 --- a/doc/develop/distro.rst +++ b/doc/develop/distro.rst @@ -81,6 +81,12 @@ as specified at `Boot Loader Specification`_: * Does not document the fdtdir option, which automatically selects the DTB to pass to the kernel. +* If no fdt/fdtdir is provided, the U-Boot will pass its own currently used + device tree. + +* If ``-`` is passed as fdt argument and ``CONFIG_SUPPORT_PASSING_ATAGS`` is + enabled, then no device tree will be used (legacy booting / pre-dtb kernel). + See also doc/README.pxe under 'pxe file format'. One example extlinux.conf generated by the Fedora installer is:: |