2013/6/25 Daniel Schwierzeck daniel.schwierzeck@gmail.com:
Hi Thomas,
oops, I hit the send key too early
Am 21.06.2013 21:59 schrieb "Langer Thomas (LQDE RD ST PON SW)" thomas.langer@lantiq.com:
Hello Daniel,
sorry for being late with my questions.
Daniel Schwierzeck wrote on 2013-06-09:
MIPS: bootm: refactor initialisation of kernel cmdline MIPS: bootm: refactor initialisation of kernel environment MIPS: bootm: make initialisation of Linux environment optional MIPS: bootm: add support for generic relocation of init ramdisks MIPS: bootm: automatically initialise kernel cmdline variable 'mem' MIPS: bootm: automatically initialise kernel cmdline variables 'rd_start' and 'rd_size'
These patches changing the style, how parameters are given to the kernel (using cmdline instead of environment)
The environment is still available
Can you explain a little, why this is necessary? Please give some references to the corresponding kernel changes or discussions, if possible.
the current U-Boot kernel interface emulates the YAMON interface. But almost all boards supported by the kernel are bootloader agnostic or don't use U-Boot.
The generic kernel interface for mem and initramfs is either commandline or device tree. IMHO it makes no sense to add bootloader specific code like environment parsing to the kernel. So I want to support the generic interfaces in U-Boot. The old environment code is still available.
And how about backward compatibility? Will it still be possible to boot older kernels?
I had no problems in my tests. Also a Lantiq BSP kernel boots fine.
When you automatically add the variable 'mem', will it still be possible to override the memory size by manually adding it to the bootargs?
I think you are referring to Lantiq's way of passing memory sizes for voice firmware to the kernel. Indeed this won't work anymore. I can add an additional if condition around the automatic code. Anyway I think it is better to always pass the full memory size to the kernel and reserve firmware memory by allocating contiguous DMA memory. Then there is no need for propietary or bootloader-specific boot interfaces.
-- Best regards, Daniel