Re: [RFC PATCH 3/3] riscv: Add riscv.fwsz kernel parameter

[Randy Dunlap]

On 11/22/21 5:57 PM, guoren@xxxxxxxxxx wrote:
> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
>
> The firmware of riscv (such as opensbi) occupy 2MB(64bit) /
> 4MB(32bit) in Linux. It's very wasteful to small memory footprint
> soc chip such as Allwinner D1s/F133. The kernel parameter gives a
> chance to users to set the proper size of the firmware and get
> more than 1.5MB of memory.
>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Anup Patel <anup.patel@xxxxxxx>
> Cc: Atish Patra <atishp@xxxxxxxxxxxx>
> ---
>   Documentation/admin-guide/kernel-parameters.txt | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 9725c546a0d4..ee505743c8f4 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4964,6 +4964,9 @@
>   			[KNL] Disable ring 3 MONITOR/MWAIT feature on supported
>   			CPUs.
>   
> +	riscv.fwsz=nn[KMG]
> +			[RISC-V] Determine firmware size to save memory

Is "Determine" like "Set"?  The user is setting (telling the software)
the firmware size?

"Determine" makes it sound to me like the Linux software is somehow
helping to determine the firmware size.

> +
>   	ro		[KNL] Mount root device read-only on boot
>   
>   	rodata=		[KNL]


--
~Randy