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| author | Neil Armstrong <narmstrong@baylibre.com> | 2021-01-20 09:54:53 +0100 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2021-01-27 10:47:54 -0500 |
| commit | 69076dff2284ed099cc0583e5e64bd8012d1ab5c (patch) | |
| tree | af66b7757762118e90e593f74da1ddcb4aef1610 /doc/README.pxe | |
| parent | b5f09df246a8a24a3b4acb669cbf95d2a063176b (diff) | |
| download | u-boot-69076dff2284ed099cc0583e5e64bd8012d1ab5c.zip u-boot-69076dff2284ed099cc0583e5e64bd8012d1ab5c.tar.gz u-boot-69076dff2284ed099cc0583e5e64bd8012d1ab5c.tar.bz2 | |
cmd: pxe: add support for FDT overlays
This adds support for specifying FDT overlays in an extlinux/pxelinux
configuration file.
Without this, there is no simple way to apply overlays when the kernel
and fdt is loaded by the pxe command.
This change adds the 'fdtoverlays' keyword for a label, supporting multiple
overlay files to be applied on top of the fdt specified in the 'fdt' or
'devicetree' keyword.
Example:
label linux
kernel /Image
fdt /soc-board.dtb
fdtoverlays /soc-board-function.dtbo
append console=ttyS0,115200 root=/dev/mmcblk0p2 rootwait
This code makes usage of a new variable called fdtoverlay_addr_r used to load
the overlay files without overwritting anything important.
Cc: Tom Rini <trini@konsulko.com>
Cc: Andre Heider <a.heider@gmail.com>
Cc: Jernej Škrabec <jernej.skrabec@siol.net>
Cc: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Jernej Škrabec <jernej.skrabec@siol.net>
Reviewed-by: Jernej Škrabec <jernej.skrabec@siol.net>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Diffstat (limited to 'doc/README.pxe')
| -rw-r--r-- | doc/README.pxe | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/doc/README.pxe b/doc/README.pxe index 42f913c..b67151c 100644 --- a/doc/README.pxe +++ b/doc/README.pxe @@ -89,6 +89,9 @@ pxe boot fdt_addr - the location of a fdt blob. 'fdt_addr' will be passed to bootm command if it is set and 'fdt_addr_r' is not passed to bootm command. + fdtoverlay_addr_r - location in RAM at which 'pxe boot' will temporarily store + fdt overlay(s) before applying them to the fdt blob stored at 'fdt_addr_r'. + pxe file format =============== The pxe file format is nearly a subset of the PXELINUX file format; see @@ -148,6 +151,12 @@ kernel <path> - if this label is chosen, use tftp to retrieve the kernel It useful for overlay selection in pxe file (see: doc/uImage.FIT/overlay-fdt-boot.txt) +fdtoverlays <path> [...] - if this label is chosen, use tftp to retrieve the DT + overlay(s) at <path>. it will be temporarily stored at the + address indicated in the fdtoverlay_addr_r environment variable, + and then applied in the load order to the fdt blob stored at the + address indicated in the fdt_addr_r environment variable. + append <string> - use <string> as the kernel command line when booting this label. |