It looks like there was going to be code to check we had some sort of
alignment so lets replace it with an actual check. This is a bit more
useful than the enigmatic "failed to read the initial flash content"
when we attempt to read the number of bytes the device should have.
This is a potential confusing stumbling block when you move from using
-bios to using -drive if=pflash,file=blob,format=raw,readonly for
loading your firmware code. To mitigate that we automatically pad in
the read-only case.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
v3
- tweak commit title/commentary
- use total_len instead of device_len for checks
- if the device is read-only do the padding for them
- accept baking_len > total_len (how to warn_report with NULL *errp?)
---
hw/block/pflash_cfi01.c | 28 +++++++++++++++++++++-------
1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 00c2efd0d7..37d7513c45 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -714,13 +714,6 @@ static void pflash_cfi01_realize(DeviceState *dev, Error
**errp)
}
device_len = sector_len_per_device * blocks_per_device;
- /* XXX: to be fixed */
-#if 0
- if (total_len != (8 * 1024 * 1024) && total_len != (16 * 1024 * 1024) &&
- total_len != (32 * 1024 * 1024) && total_len != (64 * 1024 * 1024))
- return NULL;
-#endif
-
memory_region_init_rom_device(
&pfl->mem, OBJECT(dev),
&pflash_cfi01_ops,
@@ -747,6 +740,27 @@ static void pflash_cfi01_realize(DeviceState *dev, Error
**errp)
}
if (pfl->blk) {
+ /*
+ * Validate the backing store is the right size for pflash
+ * devices. It should be padded to a multiple of the flash
+ * block size. If the device is read-only we can elide the
+ * check and just null pad the region first. If the user
+ * supplies a larger file we silently accept it.
+ */
+ uint64_t backing_len = blk_getlength(pfl->blk);
+
+ if (backing_len < total_len) {
+ if (pfl->ro) {
+ memset(pfl->storage, 0, total_len);
+ total_len = backing_len;
+ } else {
+ error_setg(errp, "device(s) needs %" PRIu64 " bytes, "
+ "backing file provides only %" PRIu64 " bytes",
+ total_len, backing_len);
+ return;
+ }
+ }
+
/* read the initial flash content */
ret = blk_pread(pfl->blk, 0, pfl->storage, total_len);
--
2.20.1
