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coreboot-kgpe-d16
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This patch implements a "flash friendly" value for initialized areas of flash. 

It makes the write part of flashrom dramatically faster with small
payloads like filo; and it also eliminates unnecessary wear on flash
by not writing zeros (it's unlikely this really matters; let me know 
next time you flash a BIOS flash 100,000 times!). 

More importantly, it allows for future partial flash upgrades with cbfs. 

Note that uninitialized_flash_value is a global that can, if we ever need it, 
be set by an argument in main. Assuming we ever see a flash where the 
"erased" value is 0, not 0xff. 

At the same time, "erased" value has been "1" on every EEPROM or 
FLASH I've used for some time now. 

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Acked-by: Peter Stuge <peter@stuge.se>




git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4290 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Ronald G. Minnich 2009-05-16 23:05:20 +00:00
parent d12acea520
commit 56ae8fcb6f
2 changed files with 11 additions and 0 deletions
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1
util/cbfstool/cbfstool.h
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@ -56,6 +56,7 @@ struct rom {
/* Function prototypes */
/* util.c */
void flashinit(void *ptr, size_t len);
int open_rom(struct rom *rom, const char *filename);
int create_rom(struct rom *rom, const unsigned char *filename, int size,
const char *bootblockname, int bootblocksize,

10
util/cbfstool/util.c
View File

@ -25,6 +25,13 @@
#include <sys/mman.h>
#include "cbfstool.h"
int uninitialized_flash_value = 0xff;
void flashinit(void *ptr, size_t len)
{
memset(ptr, uninitialized_flash_value, len);
}
int get_size(const char *size)
{
char *next;
@ -203,6 +210,9 @@ int create_rom(struct rom *rom, const unsigned char *filename,
return -1;
}
/* mmap'ed pages are by default zero-filled. Fix that. */
flashinit(rom->ptr, romsize);
/* This is a pointer to the header for easy access */
rom->header = (struct cbfs_header *)
ROM_PTR(rom, rom->size - 16 - bootblocksize - sizeof(struct cbfs_header));