coreboot-kgpe-d16/util/nvramtool
Julius Werner 09f2921b5d cbfs: Add LZ4 in-place decompression support for pre-RAM stages
This patch ports the LZ4 decompression code that debuted in libpayload
last year to coreboot for use in CBFS stages (upgrading the base
algorithm to LZ4's dev branch to access the new in-place decompression
checks). This is especially useful for pre-RAM stages in constrained
SRAM-based systems, which previously could not be compressed due to
the size requirements of the LZMA scratchpad and bounce buffer. The
LZ4 algorithm offers a very lean decompressor function and in-place
decompression support to achieve roughly the same boot speed gains
(trading compression ratio for decompression time) with nearly no
memory overhead.

For now we only activate it for the stages that had previously not been
compressed at all on non-XIP (read: non-x86) boards. In the future we
may also consider replacing LZMA completely for certain boards, since
which algorithm wins out on boot speed depends on board-specific
parameters (architecture, processor speed, SPI transfer rate, etc.).

BRANCH=None
BUG=None
TEST=Built and booted Oak, Jerry, Nyan and Falco. Measured boot time on
Oak to be about ~20ms faster (cutting load times for affected stages
almost in half).

Change-Id: Iec256c0e6d585d1b69985461939884a54e3ab900
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/13638
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2016-02-22 21:38:37 +01:00
..
accessors tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
cli utils: Remove old license text from help & disclaimer file 2016-01-13 22:53:29 +01:00
COPYING
ChangeLog
DISCLAIMER utils: Remove old license text from help & disclaimer file 2016-01-13 22:53:29 +01:00
Makefile tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
Makefile.inc tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
README
cbfs.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
cbfs.h cbfs: Add LZ4 in-place decompression support for pre-RAM stages 2016-02-22 21:38:37 +01:00
cmos_lowlevel.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
cmos_lowlevel.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
cmos_ops.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
cmos_ops.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
common.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
common.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
compute_ip_checksum.c
coreboot_tables.h
hexdump.c Remove empty lines at end of file 2015-06-08 00:55:07 +02:00
hexdump.h
input_file.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
input_file.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
ip_checksum.h
layout.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
layout.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
lbtable.c util/nvramtool: Use correct virtual address when mapping tables 2015-12-02 17:32:07 +01:00
lbtable.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
nvramtool.spec
reg_expr.c tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
reg_expr.h tree: drop last paragraph of GPL copyright header 2015-10-31 21:37:39 +01:00
win32mmap.c

README

Summary of Operation
--------------------
nvramtool is a utility for reading/writing coreboot parameters and
displaying information from the coreboot table.  It is intended for x86-based
systems (both 32-bit and 64-bit) that use coreboot.

The coreboot table resides in low physical memory, and may be accessed
through the /dev/mem interface.  It is created at boot time by coreboot, and
contains various system information such as the type of mainboard in use.  It
specifies locations in the CMOS (nonvolatile RAM) where the coreboot
parameters are stored.

For information about coreboot, see http://www.coreboot.org/.

Ideas for Future Improvements
-----------------------------
1.  Move the core functionality of this program into a shared library.
2.  Consider adding options for displaying other BIOS-provided information
    such as the MP table, ACPI table, PCI IRQ routing table, etc.