On Wed, 15 Jul 2020 16:45:04 -0400
Steven Rostedt [off-list ref] wrote:

On Thu, 16 Jul 2020 01:00:21 +0900
Masami Hiramatsu [off-list ref] wrote:

quoted

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 [off-list ref]