Commit 4dbda935 authored by Markus Armbruster's avatar Markus Armbruster
Browse files

pflash_cfi01: Log use of flawed "write to buffer" 



Our implementation of "write to buffer" (command 0xE8) is flawed.
LOG_UNIMP its use, and add some FIXME comments.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Message-Id: <20190308094610.21210-4-armbru@redhat.com>
parent 2d93bebf

hw/block/pflash_cfi01.c

+13 −0
Original line number Diff line number Diff line
@@ -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 */

                pfl->wcycle = 0;

                pfl->status |= 0x80;

            } else {