[coreboot-gerrit] Change in ...coreboot[master]: util/amdfwtool: Allow 0-length blobs

[Marshall Dawson (Code Review)]

Marshall Dawson has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/31891

Change subject: util/amdfwtool: Allow 0-length blobs
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util/amdfwtool: Allow 0-length blobs

A side effect of the change 8e0dca05
"util/amdfwtool: Add generic image copy function"
was to treat a read operation of zero bytes as a failure.  Some
implementations exist that use zero length files as a means of
removing functionality.  This causes amdfwtool to exit with an
error.

Put the zero length capability back in, and generate the requested
table entry with a length field of 0x0.

Change-Id: Ifc9204dbbf6b107f06116362358ab9d22caa71df
Signed-off-by: Marshall Dawson 
---
M util/amdfwtool/amdfwtool.c
1 file changed, 2 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/91/31891/1

diff --git a/util/amdfwtool/amdfwtool.c b/util/amdfwtool/amdfwtool.c
index 376887c..4a13b29 100644
--- a/util/amdfwtool/amdfwtool.c
+++ b/util/amdfwtool/amdfwtool.c
@@ -424,7 +424,7 @@

bytes = copy_blob(BUFF_CURRENT(*ctx),
    				fw_table[i].filename, BUFF_ROOM(*ctx));
-			if (bytes <= 0) {
+			if (bytes < 0) {
    			free(ctx->rom);
    			exit(1);
    		}
@@ -455,7 +455,7 @@
    	} else if (fw_table[i].filename != NULL) {
    		bytes = copy_blob(BUFF_CURRENT(*ctx),
    				fw_table[i].filename, BUFF_ROOM(*ctx));
-			if (bytes <= 0) {
+			if (bytes < 0) {
    			free(ctx->rom);
    			exit(1);
    		}