linux/arch/cris/arch-v10/boot/compressed
Thomas Petazzoni 2d6ffcca62 inflate: refactor inflate malloc code
Inflate requires some dynamic memory allocation very early in the boot
process and this is provided with a set of four functions:
malloc/free/gzip_mark/gzip_release.

The old inflate code used a mark/release strategy rather than implement
free.  This new version instead keeps a count on the number of outstanding
allocations and when it hits zero, it resets the malloc arena.

This allows removing all the mark and release implementations and unifying
all the malloc/free implementations.

The architecture-dependent code must define two addresses:
 - free_mem_ptr, the address of the beginning of the area in which
   allocations should be made
 - free_mem_end_ptr, the address of the end of the area in which
   allocations should be made. If set to 0, then no check is made on
   the number of allocations, it just grows as much as needed

The architecture-dependent code can also provide an arch_decomp_wdog()
function call.  This function will be called several times during the
decompression process, and allow to notify the watchdog that the system is
still running.  If an architecture provides such a call, then it must
define ARCH_HAS_DECOMP_WDOG so that the generic inflate code calls
arch_decomp_wdog().

Work initially done by Matt Mackall, updated to a recent version of the
kernel and improved by me.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:28 -07:00
..
decompress.ld [CRIS] Build fixes for compressed and rescue images for v10 and v32: 2008-06-29 23:15:19 +02:00
head.S [CRIS] Build fixes for compressed and rescue images for v10 and v32: 2008-06-29 23:15:19 +02:00
Makefile [CRIS] Correct image makefiles to allow using a separate OBJ-directory. 2008-06-30 20:38:06 +02:00
misc.c inflate: refactor inflate malloc code 2008-07-25 10:53:28 -07:00
README

Creation of the self-extracting compressed kernel image (vmlinuz)
-----------------------------------------------------------------
$Id: README,v 1.1 2001/12/17 13:59:27 bjornw Exp $

This can be slightly confusing because it's a process with many steps.

The kernel object built by the arch/etrax100/Makefile, vmlinux, is split
by that makefile into text and data binary files, vmlinux.text and 
vmlinux.data.

Those files together with a ROM filesystem can be catted together and
burned into a flash or executed directly at the DRAM origin.

They can also be catted together and compressed with gzip, which is what
happens in this makefile. Together they make up piggy.img. 

The decompressor is built into the file decompress.o. It is turned into
the binary file decompress.bin, which is catted together with piggy.img
into the file vmlinuz. It can be executed in an arbitrary place in flash.

Be careful - it assumes some things about free locations in DRAM. It
assumes the DRAM starts at 0x40000000 and that it is at least 8 MB,
so it puts its code at 0x40700000, and initial stack at 0x40800000.

-Bjorn