EEPROM support: handle implicit erase
Add support for EEPROMs with 1 byte granularity and implicit erase on
write. flashrom will not try to erase before write on these chips.
Explicitly requested erase with -E is done by writing 0xff.
Corresponding to flashrom svn r1822.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/flash.h b/flash.h
index cb53ad1..c2de2d0 100644
--- a/flash.h
+++ b/flash.h
@@ -87,6 +87,7 @@
write_gran_528bytes, /* If less than 528 bytes are written, the unwritten bytes are undefined. */
write_gran_1024bytes, /* If less than 1024 bytes are written, the unwritten bytes are undefined. */
write_gran_1056bytes, /* If less than 1056 bytes are written, the unwritten bytes are undefined. */
+ write_gran_1byte_implicit_erase, /* EEPROMs and other chips with implicit erase and 1-byte writes. */
};
/*
diff --git a/flashrom.c b/flashrom.c
index 8e5d363..408c555 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -766,6 +766,10 @@
case write_gran_1056bytes:
result = need_erase_gran_bytes(have, want, len, 1056);
break;
+ case write_gran_1byte_implicit_erase:
+ /* Do not erase, handle content changes from anything->0xff by writing 0xff. */
+ result = 0;
+ break;
default:
msg_cerr("%s: Unsupported granularity! Please report a bug at "
"flashrom@flashrom.org\n", __func__);
@@ -807,6 +811,7 @@
switch (gran) {
case write_gran_1bit:
case write_gran_1byte:
+ case write_gran_1byte_implicit_erase:
stride = 1;
break;
case write_gran_256bytes: