On 2/26/19 8:34 PM, Markus Armbruster wrote:
> Our implementation of "write to buffer" (command 0xE8) is flawed.
> LOG_UNIMP its use, and add some FIXME comments.
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
> hw/block/pflash_cfi01.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index e6d933a06d..d381f14e3c 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -502,6 +502,10 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> break;
> case 0xe8: /* Write to buffer */
> DPRINTF("%s: Write to buffer\n", __func__);
> + /* FIXME should save @offset, @width for case 1+ */
> + qemu_log_mask(LOG_UNIMP,
> + "%s: Write to buffer emulation is flawed\n",
> + __func__);
> pfl->status |= 0x80; /* Ready! */
> break;
> case 0xf0: /* Probe for AMD flash */
> @@ -545,6 +549,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> /* Mask writeblock size based on device width, or bank width if
> * device width not specified.
> */
> + /* FIXME check @offset, @width */
> if (pfl->device_width) {
> value = extract32(value, 0, pfl->device_width * 8);
> } else {
> @@ -582,7 +587,13 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> case 2:
> switch (pfl->cmd) {
> case 0xe8: /* Block write */
> + /* FIXME check @offset, @width */
> if (!pfl->ro) {
> + /*
> + * FIXME writing straight to memory is *wrong*. We
> + * should write to a buffer, and flush it to memory
> + * only on confirm command (see below).
> + */
> pflash_data_write(pfl, offset, value, width, be);
> } else {
> pfl->status |= 0x10; /* Programming error */
> @@ -598,6 +609,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> pfl->wcycle++;
> if (!pfl->ro) {
> /* Flush the entire write buffer onto backing storage. */
> + /* FIXME premature! */
> pflash_update(pfl, offset & mask, pfl->writeblock_size);
> } else {
> pfl->status |= 0x10; /* Programming error */
> @@ -614,6 +626,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> switch (pfl->cmd) {
> case 0xe8: /* Block write */
> if (cmd == 0xd0) {
> + /* FIXME this is where we should write out the buffer */
Thanks for all those comments.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
BTW I'm OK to fix that during next dev window.
Regards,
Phil.
> pfl->wcycle = 0;
> pfl->status |= 0x80;
> } else {
>