On 04/01/2021 17:21, Jernej Škrabec wrote:
Dne ponedeljek, 04. januar 2021 ob 15:41:17 CET je Tom Rini napisal(a):
On Mon, Jan 04, 2021 at 03:33:43PM +0100, Neil Armstrong wrote:
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 devicetree /soc-board.dtbThis should be "fdt /soc-board.dtb",
Indeed, thx
fdtoverlays /soc-board-function.dtbo append console=ttyS0,115200 root=/dev/mmcblk0p2 rootwaitThis 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 Signed-off-by: Neil Armstrong narmstrong@baylibre.com
Tested-by: Jernej Skrabec jernej.skrabec@siol.net
With above fix: Reviewed-by: Jernej Skrabec jernej.skrabec@siol.net
Hi Tom,
This is repost of my last year's attempt. It fills a hole to allow loading FDT overlays using PXE/Extlinux without using FIT.
V2 adds documentation.
Thanks for following up. I assume this follows what the spec says for this file?
Which specs? Official extlinux configuration specs [1] don't say anything about device tree files, so anything related to that is an extension (I hope I found correct specs). I think this one is extremely useful, users can easily specify which overlay file(s) they want to be applied in a text file.
Indeed, it follows the spec by not breaking it and simply extends the already u-boot specific pxe format.
Neil
Best regards, Jernej
[1] https://repo.or.cz/syslinux.git/blob/HEAD:/doc/syslinux.txt