[XS] Change in coreboot[main]: util/ifdtool: Enable Read Access for SPI device expansion 2 region

[Subrata Banik (Code Review)]

Subrata Banik has submitted this change. ( https://review.coreboot.org/c/coreboot/+/79902?usp=email )

Change subject: util/ifdtool: Enable Read Access for SPI device expansion 2 region
......................................................................

util/ifdtool: Enable Read Access for SPI device expansion 2 region

As per Intel Meteor Lake SPI programming doc, the BIOS region should
have a read access enabled for device expansion 2 region
(aka region 9).

This patch ensures that BIOS region is able to read the device
expansion 2 region for Intel Meteor Lake platform as known as
SPI padding region.

BUG=b:274356894
BRANCH=firmware-rex-15709.B
TEST=Able to flash screebo AP FW image using flashrom on DUT.

Without this patch:
> flashrom -p internal -r /tmp/bios.rom

flashrom 1.4.0-devel on Linux 6.1.67-09255-ge8ae3115f8b0 (x86_64)
...
...
Found Winbond flash chip "W25Q256JW_DTR" (32768 kB, Programmer-specific)
on internal.
Reading flash... Transaction error between offset 0x0072f000 and
0x0072f03f (= 0x0072f000 + 63)!
read_flash: failed to read (0x72f000..0x7fffff).
Read operation failed!
FAILED.
FAILED

With this patch:
> flashrom -p internal -r /tmp/bios.rom

flashrom 1.4.0-devel on Linux 6.1.68-09294-g001fdda5287d (x86_64)
...
...
Found Winbond flash chip "W25Q256JW_DTR" (32768 kB, Programmer-specific)
on internal.
Reading flash... done.
SUCCESS

Change-Id: I18c44aa9a0f890f01a889247da118b69a58936e8
Signed-off-by: Subrata Banik 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79902
Tested-by: build bot (Jenkins) 
Reviewed-by: Kapil Porwal 
Reviewed-by: Reka Norman 
Reviewed-by: Eric Lai 
---
M util/ifdtool/ifdtool.c
1 file changed, 4 insertions(+), 0 deletions(-)

Approvals:
  Reka Norman: Looks good to me, approved
  Kapil Porwal: Looks good to me, approved
  build bot (Jenkins): Verified
  Eric Lai: Looks good to me, approved

diff --git a/util/ifdtool/ifdtool.c b/util/ifdtool/ifdtool.c
index 99a83e5..191b321 100644
--- a/util/ifdtool/ifdtool.c
+++ b/util/ifdtool/ifdtool.c
@@ -1451,6 +1451,10 @@
    		fmba->flmstr5 |= (1 << REGION_EC) << rd_shift;
    		fmba->flmstr5 |= (1 << REGION_EC) << wr_shift;
    	}
+		if (check_region(frba, REGION_DEV_EXP2)) {
+			/* BIOS can read SPI device expansion 2 region. */
+			fmba->flmstr1 |= (1 << REGION_DEV_EXP2) << rd_shift;
+		}
    	break;
    case PLATFORM_DNV:
    case PLATFORM_WBG: