[S] Change in coreboot[master]: util/ifdtool/ifdtool.c: Fix default FMAP generation

[Martin L Roth (Code Review)]

Martin L Roth has submitted this change. ( https://review.coreboot.org/c/coreboot/+/74735 )

Change subject: util/ifdtool/ifdtool.c: Fix default FMAP generation
......................................................................

util/ifdtool/ifdtool.c: Fix default FMAP generation

According to SPI programming guide, a region limit of 0 as well as
region base of 7FFFh indicates an unused/reserved region.

Signed-off-by: Maximilian Brune 
Change-Id: I790d7f5631ecef3043b2c17c41430dc4fd854f72
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74735
Tested-by: build bot (Jenkins) 
Reviewed-by: Matt DeVillier 
---
M util/ifdtool/ifdtool.c
1 file changed, 26 insertions(+), 4 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Matt DeVillier: Looks good to me, approved

diff --git a/util/ifdtool/ifdtool.c b/util/ifdtool/ifdtool.c
index 625b4cf..ada120b 100644
--- a/util/ifdtool/ifdtool.c
+++ b/util/ifdtool/ifdtool.c
@@ -457,8 +457,11 @@

for (unsigned int i = 0; i < max_regions; i++) {
    	struct region region = get_region(frba, i);
-		/* is region invalid? */
-		if (region.size < 1)
+
+		/* A region limit of 0 is an indicator of an unused region
+		 * A region base of 7FFFh is an indicator of a reserved region
+		 */
+		if (region.limit == 0 || region.base == 0x07FFF000)
    		continue;

char buf[LAYOUT_LINELEN];
@@ -1027,8 +1030,11 @@
    struct region sorted_regions[MAX_REGIONS] = { 0 };
    for (unsigned int i = 0; i < max_regions; i++) {
    	struct region region = get_region(frba, i);
-		/* is region invalid? */
-		if (region.size < 1)
+
+		/* A region limit of 0 is an indicator of an unused region
+		 * A region base of 7FFFh is an indicator of a reserved region
+		 */
+		if (region.limit == 0 || region.base == 0x07FFF000)
    		continue;

/* Here we decide to use the coreboot generated FMAP BIOS region, instead of