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authorRonald G. Minnich <rminnich@gmail.com>2009-05-16 23:05:20 +0000
committerRonald G. Minnich <rminnich@gmail.com>2009-05-16 23:05:20 +0000
commit56ae8fcb6fe545557c6b5a3ffb72f54bd3b53ddc (patch)
tree9f7211f81edcc80576a73058c340ad2338ee9aa5 /util/cbfstool/util.c
parentd12acea520840b64804ec7f2d1b9fba423ed194e (diff)
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
Diffstat (limited to 'util/cbfstool/util.c')
-rw-r--r--util/cbfstool/util.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/util/cbfstool/util.c b/util/cbfstool/util.c
index b36e9187a0..f0c0b293cf 100644
--- a/util/cbfstool/util.c
+++ b/util/cbfstool/util.c
@@ -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));