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b88556979b
During the conversion of flash chip accesses to helper functions, I spotted
assignments to volatile variables which were neither placed inside the mmapped
ROM area nor were they counters.
Due to the use of accessor functions, volatile usage can be reduced
significantly because the accessor functions take care of actually
performing the reads/writes correctly.
The following semantic patch spotted them (linebreak in python string
for readability reasons, please remove before usage):
@r exists@
expression b;
typedef uint8_t;
volatile uint8_t a;
position p1;
@@
a@p1 = readb(b);
@script:python@
p1 << r.p1;
a << r.a;
b << r.b;
@@
print "* file: %s line %s has assignment to unnecessarily volatile
variable: %s = readb(%s);" % (p1[0].file, p1[0].line, a, b)
Result was:
HANDLING: sst28sf040.c
* file: sst28sf040.c line 44 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 43 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 42 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 41 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 40 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 39 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 38 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 58 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 57 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 56 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 55 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 54 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 53 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
* file: sst28sf040.c line 52 has assignment to unnecessarily volatile
variable: tmp = readb(TODO: Binary);
The following semantic patch uses the spatch builtin match printing
functionality by prepending a "*" to the line with the pattern:
@@
expression b;
typedef uint8_t;
volatile uint8_t a;
@@
* a = readb(b);
Result is:
HANDLING: sst28sf040.c
diff =
- tmp = readb(bios + 0x1823);
- tmp = readb(bios + 0x1820);
- tmp = readb(bios + 0x1822);
- tmp = readb(bios + 0x0418);
- tmp = readb(bios + 0x041B);
- tmp = readb(bios + 0x0419);
- tmp = readb(bios + 0x040A);
}
static __inline__ void unprotect_28sf040(volatile uint8_t *bios)
@@ -49,13 +42,6 @@ static __inline__ void unprotect_28sf040
/* ask compiler not to optimize this */
volatile uint8_t tmp;
- tmp = readb(bios + 0x1823);
- tmp = readb(bios + 0x1820);
- tmp = readb(bios + 0x1822);
- tmp = readb(bios + 0x0418);
- tmp = readb(bios + 0x041B);
- tmp = readb(bios + 0x0419);
- tmp = readb(bios + 0x041A);
}
static __inline__ int erase_sector_28sf040(volatile uint8_t *bios,
It's arguably a bit easier to read if you get used to the leading "-"
for matching lines.
This patch was enabled by Coccinelle:
http://www.emn.fr/x-info/coccinelle/
Corresponding to flashrom svn r419 and coreboot v2 svn r3973.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Joseph Smith <joe@settoplinux.org>
-------------------------------------------------------------------------------
Flashrom README
-------------------------------------------------------------------------------
Flashrom is a universal flash programming utility for DIP, PLCC, or SPI
flash ROM chips. It can be used to flash BIOS/coreboot/firmware images.
(see http://coreboot.org for details on coreboot)
Build Requirements
------------------
To build the flashrom utility you need to install the following packages:
* pciutils
* pciutils-devel / pciutils-dev / libpci-dev
* zlib-devel / zlib1g-dev
Usage
-----
$ flashrom [-rwvEVfLhR] [-c chipname] [-s exclude_start] [-e exclude_end]
[-m [vendor:]part] [-l file.layout] [-i imagename] [file]
-r | --read: read flash and save into file
-w | --write: write file into flash (default when
file is specified)
-v | --verify: verify flash against file
-E | --erase: erase flash device
-V | --verbose: more verbose output
-c | --chip <chipname>: probe only for specified flash chip
-s | --estart <addr>: exclude start position
-e | --eend <addr>: exclude end postion
-m | --mainboard <[vendor:]part>: override mainboard settings
-f | --force: force write without checking image
-l | --layout <file.layout>: read rom layout from file
-i | --image <name>: only flash image name from flash layout
-L | --list-supported: print supported devices
-h | --help: print this help text
-R | --version: print the version (release)
If no file is specified, then all that happens
is that flash info is dumped and the flash chip is set to writable.
Exit status
-----------
flashrom exits with 0 on success, 1 on most failures but with 2 if /dev/mem
(/dev/xsvc on Solaris) can not be opened and with 3 if a call to mmap() fails.
coreboot Table and Mainboard Identification
--------------------------------------------
Flashrom reads the coreboot table to determine the current mainboard
(parse DMI as well in future?). If no coreboot table could be read
or if you want to override these values, you can specify -m, e.g.:
$ flashrom -w --mainboard AGAMI:ARUMA agami_aruma.rom
See the 'Supported mainboards' section in the output of 'flashrom -L' for
a list of boards which require the specification of the board name, if no
coreboot table is found.
ROM Layout Support
------------------
Flashrom supports ROM layouts. This allows you to flash certain parts of
the flash chip only. A ROM layout file looks like follows:
00000000:00008fff gfxrom
00009000:0003ffff normal
00040000:0007ffff fallback
i.e.:
startaddr:endaddr name
All addresses are offsets within the file, not absolute addresses!
If you only want to update the normal image in a ROM you can say:
flashrom -w --layout rom.layout --image normal agami_aruma.rom
To update normal and fallback but leave the VGA BIOS alone, say:
flashrom -w -l rom.layout -i normal -i fallback agami_aruma.rom
Currently overlapping sections are not supported.
ROM layouts should replace the -s and -e option since they are more
flexible and they should lead to a ROM update file format with the
ROM layout and the ROM image in one file (cpio, zip or something?).
Disk on Chip support
--------------------
Disk on Chip support was removed from flashrom in r3382. It had already
been disabled by default in flashrom for several years because the code
was considered unstable and incomplete. The products intended to work
have been End-Of-Lifed by the manufacturer for a long time.
Supported Flash Chips / Chipsets / Mainboards
---------------------------------------------
Please check the output of 'flashrom -L' for the list of supported
flash chips, chipsets/southbridges, and mainboards.
See also http://coreboot.org/Flashrom for more details.