coreboot

History

Ronald G. Minnich 6b4477c8cb Add a zero-fill command to lar. Signed-off-by: Ronald G. Minnich <rminnich@gmail.com> Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net> Note: the following discussion applies to this patch. This patch is basically limited. It is mostly useful for newly-created LARs. On Feb 9, 2008 1:06 PM, Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net> wrote: > If I read the code correctly, the command will try to fill the first > occurrence of free space in the lar, not the biggest one. That means > we > might have to call it multiple times. hmm. I obviously did not think of this. > And a general problem with the code: If it finds the offset of the > first > empty area, it checks whether the area is big enough. If not, it does > not search for another empty area, but returns instead with an error. Actually, I think as written it is broken for the general case of lots of empty spots. It should just look for the room left from start of empty space to next LAR header. It's just that I have never had a LAR that has more than one block of empty space, and that empty space is always at the gap before the bootblock. How about this. I'd like to commit now, and then fix this later, as I really need this code in there for speed and it works fine with all "fresh" images built with v3. > Should we really call this "zerofill"? "emptyfill"? I'll let it go for now but you make good point. > Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net> OK, this is clearly a work in progress but even in this form it is so useful I'm going to commit it with a note, "This needs more work", and with luck someone else will improve it once we need it improved -- the basic structure is there. Index: util/lar/stream.c Add hlen (header len) and maxsize (max size left in lar) functions. Index: util/lar/lib.h Add function prototypes and new ZEROFILL enum. Index: util/lar/lar.c Add -z option and command support. git-svn-id: svn://coreboot.org/repository/coreboot-v3@583 f3766cd6-281f-0410-b1cd-43a5c92072e9		2008-02-09 21:16:42 +00:00
..
bootblock.c	Now version 3: LinuxBIOS -> coreboot rename.	2008-01-27 18:54:57 +00:00
example.c	Now version 3: LinuxBIOS -> coreboot rename.	2008-01-27 18:54:57 +00:00
lar.c	Add a zero-fill command to lar.	2008-02-09 21:16:42 +00:00
lar.h	Cache the ROM to speed up stage2 and payload decompression.	2008-02-06 02:36:50 +00:00
lib.c	Now version 3: LinuxBIOS -> coreboot rename.	2008-01-27 18:54:57 +00:00
lib.h	Add a zero-fill command to lar.	2008-02-09 21:16:42 +00:00
Makefile	Now version 3: LinuxBIOS -> coreboot rename.	2008-01-27 18:54:57 +00:00
README	Now version 3: LinuxBIOS -> coreboot rename.	2008-01-27 18:54:57 +00:00
stream.c	Add a zero-fill command to lar.	2008-02-09 21:16:42 +00:00

README

Lightweight Archiver: lar
-----------------------

Table of Contents
  - Introduction
  - Usage
  - Archive format
  - TODO
  - Copyright and License


Introduction
------------

This is a simple archiver, similar to cpio, ar or tar. It was designed and
written for coreboot.

Design goals were
  - minimum overhead
  - maximum fault tolerance
  - simplicity

For a usage example see example.c.

For questions contact Stefan Reinauer <stepan@coresystems.de>.


Usage
-----

Create archive archive.lar containing files file1 ... fileN:

  $ lar c archive.lar file1 ... fileN

Extract files from archive.lar:

  $ lar x archive.lar [file1 ... fileN]

List files in archive:

  $ lar l archive.lar


Archive format
--------------

The rough format is:

 |--------------|
 | header       |
 |--------------|
 | data         |
 |--------------|
 | header       |
 |--------------|
 | data         |
 |--------------|
  ...

Headers have to be 16 byte aligned.

 |----------------------------|
 | magic (8 bytes)            |
 |----------------------------|
 | length (4 bytes)           |
 |----------------------------|
 | checksum (4 bytes)         |
 |----------------------------|
 | offset to blob (4 bytes)   |
 |----------------------------|
 | "path name"                | <-- null terminated, aligned to 16 bytes
 |----------------------------|
 | blob (aligned to 16 bytes) |
 |----------------------------|


TODO
----

  - Reading flash layouts
  - This does not enforce any alignment yet
  - Alignment enforcing will be optional


Copyright and License
---------------------

Copyright (C) 2006-2007 coresystems GmbH
Written by Stefan Reinauer <stepan@coresystems.de> for coresystems GmbH.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA

Note: The files lar.h and example.c are dual-licensed. You can choose between:
 - The GNU GPL, version 2, as published by the Free Software Foundation.
 - The revised BSD license (without advertising clause). See lar.h.