Re: [PATCH 0/3] bootconfig: Add value override operator

[Masami Hiramatsu]

On Wed, 15 Jul 2020 16:45:04 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Thu, 16 Jul 2020 01:00:21 +0900
> Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
> 
> > With this change, if the bootloader wants to change some value
> > in the default bootconfig, it doesn't need to parse the existing
> > bootconfig, but it can just append the new configs at the tail
> > of the bootconfig and update the footer (size, checksum and magic
> > word).
> 
> I wonder if we should support multiple bootconfigs instead of updating
> the size/checksum/magic?
> 
> So the end of the initrd would have:
> 
>  [data][size/checksum/magic][more-data][size/checksum/magic]
> 
> 
> And the kernel could do the following:
> 
>  1. read the end of the initrd for bootconfig
>  2. If found parse the bootconfig data.
>  3. look at the content before the bootconfig
>  4. if another bootconfig exists, goto 2.
> 

Yeah, that is possible. But since the total size of the bootconfig
is limited to 32KB (this means data + 1st footer + more-data),
I would like to give a chance of sanity check to the bootloader.

Thank you,

-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>