---
hw/block/pflash_cfi02.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c
index d30a351472..db1c39499c 100644
--- a/hw/block/pflash_cfi02.c
+++ b/hw/block/pflash_cfi02.c
@@ -578,8 +578,9 @@ static void pflash_cfi02_realize(DeviceState *dev, Error
**errp)
if (pfl->blk) {
/*
* Validate the backing store is the right size for pflash
- * devices. If the user supplies a larger file we ignore the
- * tail.
+ * devices. If the device is read-only we can elide the check
+ * and just pad the region first. If the user supplies a
+ * larger file we ignore the tail.
*/
int64_t backing_len = blk_getlength(pfl->blk);
if (backing_len < 0) {
@@ -588,9 +589,20 @@ static void pflash_cfi02_realize(DeviceState *dev, Error
**errp)
}
if (backing_len < chip_len) {
- error_setg(errp, "device needs %" PRIu32 " bytes, "
- "backing file provides only %" PRIu64 " bytes",
- chip_len, backing_len);
+ if (pfl->ro) {
+ size_t pad_bytes = chip_len - backing_len;
+ /* pad with NOR erase pattern */
+ memset((uint8_t *)pfl->storage + backing_len,
+ 0xff, pad_bytes);
+ warn_report("device needs %" PRIu32
+ " bytes, padded with %zu 0xff bytes",
+ chip_len, pad_bytes);
+ chip_len = backing_len;
+ } else {
+ error_setg(errp, "device needs %" PRIu32 " bytes, "
+ "backing file provides only %" PRIu64 " bytes",
+ chip_len, backing_len);
+ }
return;
} else if (backing_len > chip_len) {
warn_report("device needs %" PRIu32 " bytes, rest ignored",
--
2.17.2
