[Cbe-oss-dev] PS3 Linux boot loader discussions

[Hiroyuki Machida]

Hi All,

I'm working on PS3/Cell Linux Project in Sony/SCEI. I'd like to
open up discussions about expected behaviors of PS3 Boot Loader.
I hope we'll have consensus to same sort of standards or conventions,
so that Linux Distribution Installer CD/DVDs keep work well and 
avoid users confuse. 

Please take a look attached material and give your feedbacks.

Chears,
Hiroyuki Machida

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* Summary
 I'd like to propose and open up discussion on standard conventions of 
 PS3 bootloader configuration file format, it's path name and expected 
 behavior,  to get better support Linux Distribution Install Kit.

* Background
 Recently Linux Installers going to support PS3 and I saw various
 bootloaders derived from the kboot of Add-on CD. Unfortunately
 some of those bootloaders are not necessary, due to 
 misunderstanding.

 In addition to the above, the GUI boot loader project has been
 launched. I guess in future, some one may try to replace kboot
 with other smaller bootloader.

 I believe it's time to elaborate 
  1) what's expected boot loader behavior for Linux
   Distribution Install Kit Media like CD/DVD, 
  2) How current kboot in the Add-on CD works to well such 
   with requirements (or not)
  3) What's desirable for boot config file.


* Requirements
 a) Boot from Removable Media where Linux Installer is.
 b) Keep compatibility with current Kboot on the Add-on CD.
 c) Acceptable to future Kboot replacement.

* Current Status
 Current Kboot on the Add-on CD already supports requirement a).
 It recognize the removable media is bootable, if it found
 /etc/kboot.conf in the media.
 That means, if Linux Install Kit DVD has /etc/kboot.conf to start
 install script, current kboot will follow it. There is no reason 
 to rebuild and re-install own kboot for each Linux Distribution 
 just for adding own install script.

* Proposal
 - Title
 Standard Conventions to  bootloader for Linux on PS3

 - Target
  bootloader for Linux on PS3

 - A bootloader for PS3 Linux needs to meet following conventions, if
  it supports bootable media.

 1)  path name of boot config file
   /etc/kboot.conf on media

 2) algorithm to detect bootable media
   - A bootloader will recognize the media is bootable when
   /etc/kboot.conf is found.
   - Priority of bootable media is up to boot loader implementation.

 3) Bootloader config file format
   - Bootloader config file format allows kboot.conf documents.
   However shell specific rich functions like back quote are not be
   supported for future possible kboot replacement.

 4) Bootable media type and it's format
   - Supported bootable media types are up to boot loader implementation.
   - When bootloader supports following media type, it needs to
     support corresponding Std. format at least.

   TYPE  - Std. Format
   ------------------------
   USB memory - FAT
   CD - ISO9660
   DVD - UDF

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Hiroyuki.Machida at Jp.Sony.Com
Hiroyuki_Machida at hq.scei.sony.co.jp