[coreboot] [PATCH] flashrom: Use REMS instead of RES in the ICH SPI opcode table

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Sat May 16 01:30:55 CEST 2009


Use REMS instead of RES in the ICH SPI default opcode table.

RES is Read Electronic Signature (1 Byte, identical for different chips)
REMS is Read Electronic Manufacturer Signature (2 Bytes, unique)

Of the chips which don't support RDID, a sizable portion supports REMS
which gives us both a manufacturer ID and a device ID. This is clearly
superior to having only a device ID (the RES case) which has multiple
documented collisions.

The best way forward would be to have the ICH SPI driver reprogram the
opcode menu on the fly if the opcode menu doesn't contain the requested
opcode and the opcode menu is not locked. Until that happens, this patch
improves detection accuracy by a factor of 256 for some chips.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net>

Index: flashrom-ichspi_res_rems_exchange/ichspi.c
===================================================================
--- flashrom-ichspi_res_rems_exchange/ichspi.c	(Revision 515)
+++ flashrom-ichspi_res_rems_exchange/ichspi.c	(Arbeitskopie)
@@ -186,7 +186,7 @@
 	 {JEDEC_READ, SPI_OPCODE_TYPE_READ_WITH_ADDRESS, 0},	// Read Data
 	 {JEDEC_BE_D8, SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS, 1},	// Erase Sector
 	 {JEDEC_RDSR, SPI_OPCODE_TYPE_READ_NO_ADDRESS, 0},	// Read Device Status Reg
-	 {JEDEC_RES, SPI_OPCODE_TYPE_READ_WITH_ADDRESS, 0},	// Resume Deep Power-Down
+	 {JEDEC_REMS, SPI_OPCODE_TYPE_READ_WITH_ADDRESS, 0},	// Read Electronic Manufacturer Signature
 	 {JEDEC_WRSR, SPI_OPCODE_TYPE_WRITE_NO_ADDRESS, 1},	// Write Status Register
 	 {JEDEC_RDID, SPI_OPCODE_TYPE_READ_NO_ADDRESS, 0},	// Read JDEC ID
 	 {JEDEC_CE_C7, SPI_OPCODE_TYPE_WRITE_NO_ADDRESS, 1},	// Bulk erase


-- 
http://www.hailfinger.org/

-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: flashrom_ichspi_res_rems_exchange.diff
URL: <http://www.coreboot.org/pipermail/coreboot/attachments/20090516/7bffc372/attachment.ksh>


More information about the coreboot mailing list