On 08/14/2014 08:04 AM, Youngmin Nam wrote:
Thank you for reply Tom, Let me ask you some questions.
Can we set kernel's bootargs without re-compiling device tree on arm64 kernel by u-boot?
I mean, I want to set kernel's bootargs by u-boot without re-compiling device tree.
Is it possible?
This is done anyway, whatever is defined in CONFIG_BOOTARGS will be stored in the U-Boot environment variable bootargs and passed as bootargs to the kernel via the "chosen" node.
See fdt_chosen in common/fdt-support.c.
So if you want the change the bootargs passed to the kernel, just do
set bootargs '<whatever you want in bootargs>'
at the u-boot prompt and the boot the kernel.
Thanks Arnab
- 오후 7:39에 "Tom Rini" trini@ti.com님이 작성:
On Wed, Aug 13, 2014 at 11:21:32AM +0900, Youngmin Nam wrote:
Hello. I'm trying to find a way how to pass bootargs to arm64 kernel.
In arm32 kernel, we can pass bootargs with atag from u-boot to kernel.
So,
we can overwrite kernel's bootargs with u-boot's bootargs.
But from arm64 kernel, the dtb is the only argument that should be passed from bootloader which is mandatory. you can find this contents in kernel documentation.(Documentation/arm64/Booting.txt)
So, is there any way how to set bootargs by u-boot?
Yes, within the device tree, like we do today. There's a few issues we have today, but I need to re-post the booti command support patches, given what's coming in 3.17 in the kernel.
-- Tom