David Hendricks has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/30521
Change subject: dediprog: Use 4BA page program without 0x12
......................................................................
dediprog: Use 4BA page program without 0x12
It's not clear exactly what the difference is between
WRITE_MODE_4B_ADDR_256B_PAGE_PGM with and without _0x12 from the SF600
command spec, but the former seems to work more reliably.
Tested using an SF600 (FW v7.2.21), IS25LP256D, W25Q256JV, and
MX25L25735.
Change-Id: I3cb37ec8838f5bb02948ed52b4a2906fa033cf83
Signed-off-by: David Hendricks <david.hendricks(a)gmail.com>
---
M dediprog.c
1 file changed, 2 insertions(+), 1 deletion(-)
git pull ssh://review.coreboot.org:29418/flashrom refs/changes/21/30521/1
diff --git a/dediprog.c b/dediprog.c
index 2a190d2..303f1d5 100644
--- a/dediprog.c
+++ b/dediprog.c
@@ -398,7 +398,8 @@
}
} else if (dedi_spi_cmd == WRITE_MODE_PAGE_PGM) {
if (flash->chip->feature_bits & FEATURE_4BA_WRITE) {
- data_packet[3] = WRITE_MODE_4B_ADDR_256B_PAGE_PGM_0x12;
+// data_packet[3] = WRITE_MODE_4B_ADDR_256B_PAGE_PGM_0x12;
+ data_packet[3] = WRITE_MODE_4B_ADDR_256B_PAGE_PGM;
data_packet[4] = JEDEC_BYTE_PROGRAM_4BA;
use_4ba = true;
} else if (flash->in_4ba_mode) {
--
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Gerrit-Change-Id: I3cb37ec8838f5bb02948ed52b4a2906fa033cf83
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David Hendricks has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/36986 )
Change subject: mysteries_intel: Add a section about SMM_BWP
......................................................................
mysteries_intel: Add a section about SMM_BWP
Something to point users to when SMM_BWP might be causing problems.
Change-Id: I394c033e8d4ff96433162f86aefb428d8acf6349
Signed-off-by: David Hendricks <david.hendricks(a)gmail.com>
---
M Documentation/mysteries_intel.txt
1 file changed, 19 insertions(+), 0 deletions(-)
git pull ssh://review.coreboot.org:29418/flashrom refs/changes/86/36986/1
diff --git a/Documentation/mysteries_intel.txt b/Documentation/mysteries_intel.txt
index 10cb37d..d6ceb6a 100644
--- a/Documentation/mysteries_intel.txt
+++ b/Documentation/mysteries_intel.txt
@@ -5,6 +5,25 @@
A0h), so we have no clue if or where it is on ICH8. Out current policy is to
not touch it at all and assume/hope it is 0.
+= SMM BIOS write protection =
+Sometimes a hardware vendor will enable "SMM BIOS Write Protect" (SMM_BWP).
+The bits that control this are in the BIOS_CNTL register in the LPC interface.
+
+When enabled, the SPI flash can only be written when the system is operating in
+in System Management Mode (SMM). In other words, only code that was installed by
+the BIOS can write to the flash chip. Reads are still possible with code that
+runs outside of SMM, such as flashrom.
+
+Flashrom will attempt to detect this and print a message such as the following:
+"Warning: BIOS region SMM protection is enabled!"
+
+Many vendor-supplied firmware update utilities do not actually write to the ROM;
+instead they transfer data to/from memory which is read/written by a routine
+running in SMM and is responsible for writing to the firmware ROM. This causes
+severe system performance degradataion since all processors must be in SMM
+context (ring -2) instead of OS context (ring 0) while the firmware ROM is being
+written.
+
= Accesses beyond region bounds in descriptor mode =
Intel's flash image tool will always expand the last region so that it covers
the whole flash chip, but some boards ship with a different configuration.
--
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