[syslinux] KRNLINUX? CPIOLINUX?

[Shao Miller]

On 8/19/2011 01:37, H. Peter Anvin wrote:
> On 08/16/2011 06:03 PM, Shao Miller wrote:
>> Does anyone think that it might be a worth-while effort to code a
>> Syslinux variant which is a "Linux x86 kernel"-format binary and whose
>> "initrd" is a simple cpio archive which will comprise the root 
>> filesystem?
> There are definitely use cases for this. It would be interesting to have.

Design decision(s):

Do we leave the initramfs' in-memory representation intact, for the 
potential purpose of actually "re-passing" the very same initramfs to a 
Linux?  If so, then we either:
- [potentially] walk the whole initramfs for every file access, or
- do a one-time pass and allocate [a bunch of] memory to do file 
accounting (such as tracking the position of file data for files 
overwritten by concatenated archives)

Or:

Can I [ab]use the initramfs' range of memory to [slightly] re-organize 
into a more efficient "filesystem" with a one-time pass?

Also: Do we make this a "cpio FS" driver that uses the block-caching 
abstraction (and hook the disk I/O to actually do memory access, 
instead) or do we make this an "initramfs" driver that will never allow 
for supporting initramfs on a disk, but only in memory?  I could see a 
use for the former, if we every wish to allow "mounting" initramfs files 
that are not in memory, but it seems a tad more complicated.

- Shao Miller