This is a very simple series that try to solve a very simple problem. Many emebedded devices have very hacked (by OEMS) bootloader that do all kind of modification and makes the kernel unbootable with the very first small modification. And also many times these broken bootloader have hardcoded values that can't be modified and would require risky procedure that can brick the device. One of the common modification done is hardcoding bootargs in the appended kernel DT trashing the bootargs set in the /chosen. The main usage of this is to have dynamic stuff to support dual partition scheme and make the kernel load a dedicated rootfs. But the other usage of this is to effectively lockup the device and cause kernel panic on modification like using squashfs instead of legacy jffs2. The simple solution to this is to let the bootloader override the bootargs in /chosen and make the kernel parse a different property. >From long time on OpenWRT we use bootargs-override as the alternative property for this task fixing the problem of overridden bootargs. The second feature is bootargs-append. This is self-explanatory, sometimes bootargs from bootloader might be good but lack of some crucial things that needs to be appended, like rootfstype or rootfs path. This feature is different than hardcoding the CMDLINE since that is usable only with some specific case and is really problematic if the same kernel is used for multiple devices that share a common kernel and .dtsi Christian Marangi (3): docs: dt: Document new bootargs chosen property of: add support for bootargs-override chosen property of: add support for bootargs-append chosen property David Bauer (1): MIPS: add bootargs-override property Documentation/devicetree/usage-model.rst | 9 +++++++++ arch/mips/kernel/setup.c | 14 +++++++++++++- drivers/of/fdt.c | 15 +++++++++++++-- 3 files changed, 35 insertions(+), 3 deletions(-) -- 2.43.0
