Two trivial comments: On 02/22/19 16:44, Alex Bennée wrote: > 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 and warn the user when we have performed magic to > enable things to Just Work (tm). > > 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?) > v4 > - error check blk_getlength > - optimise memset and use NOR erase pattern > - restore singular device (overly confusing) > - add warn_report for when we do magic > --- > hw/block/pflash_cfi01.c | 40 +++++++++++++++++++++++++++++++++------- > 1 file changed, 33 insertions(+), 7 deletions(-) > > diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c > index 00c2efd0d7..c69ecc20a0 100644 > --- a/hw/block/pflash_cfi01.c > +++ b/hw/block/pflash_cfi01.c > @@ -45,6 +45,7 @@ > #include "qemu/bitops.h" > #include "qemu/host-utils.h" > #include "qemu/log.h" > +#include "qemu/error-report.h" > #include "hw/sysbus.h" > #include "sysemu/sysemu.h" > #include "trace.h" > @@ -714,13 +715,6 @@ 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 +741,38 @@ 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
(1) We no longer null-pad, but one-pad (bit-wise). I don't think it's too confusing though. > + * supplies a larger file we ignore the tail. > + */ > + int64_t backing_len = blk_getlength(pfl->blk); > + if (backing_len < 0) { > + error_setg(errp, "unable to check size of backing file"); > + return; > + } > + > + if (backing_len < total_len) { > + if (pfl->ro) { > + size_t pad_bytes = total_len - backing_len; > + /* pad with NOR erase pattern */ > + memset((uint8_t*)pfl->storage + backing_len, 0xff, > pad_bytes); > + warn_report("device needs %" PRIu64 > + " bytes, padded with %zd 0xff bytes", (2) I think %zu would be more appropriate for size_t, but it's not a showstopper. > + total_len, pad_bytes); > + total_len = backing_len; > + } else { > + error_setg(errp, "device needs %" PRIu64 " bytes, " > + "backing file provides only %" PRIu64 " bytes", > + total_len, backing_len); > + return; > + } > + } else if (backing_len > total_len) { > + warn_report("device needs %" PRIu64 " bytes, rest ignored", > total_len); > + } > + > /* read the initial flash content */ > ret = blk_pread(pfl->blk, 0, pfl->storage, total_len); > > No need to repost just because of these. Reviewed-by: Laszlo Ersek <ler...@redhat.com> Thanks! Laszlo