diff options
| -rw-r--r-- | hw/block/pflash_cfi01.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c index 82a2519113..de7a6c0847 100644 --- a/hw/block/pflash_cfi01.c +++ b/hw/block/pflash_cfi01.c @@ -74,6 +74,7 @@ struct pflash_t { uint64_t sector_len; uint8_t bank_width; uint8_t device_width; /* If 0, device width not specified. */ + uint8_t max_device_width; /* max device width in bytes */ uint8_t be; uint8_t wcycle; /* if 0, the flash is read normally */ int ro; @@ -635,6 +636,13 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp) pfl->ro = 0; } + /* Default to devices being used at their maximum device width. This was + * assumed before the device_width support was added. + */ + if (!pfl->max_device_width) { + pfl->max_device_width = pfl->device_width; + } + pfl->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, pflash_timer, pfl); pfl->wcycle = 0; pfl->cmd = 0; @@ -728,8 +736,25 @@ static Property pflash_cfi01_properties[] = { DEFINE_PROP_DRIVE("drive", struct pflash_t, bs), DEFINE_PROP_UINT32("num-blocks", struct pflash_t, nb_blocs, 0), DEFINE_PROP_UINT64("sector-length", struct pflash_t, sector_len, 0), + /* width here is the overall width of this QEMU device in bytes. + * The QEMU device may be emulating a number of flash devices + * wired up in parallel; the width of each individual flash + * device should be specified via device-width. If the individual + * devices have a maximum width which is greater than the width + * they are being used for, this maximum width should be set via + * max-device-width (which otherwise defaults to device-width). + * So for instance a 32-bit wide QEMU flash device made from four + * 16-bit flash devices used in 8-bit wide mode would be configured + * with width = 4, device-width = 1, max-device-width = 2. + * + * If device-width is not specified we default to backwards + * compatible behaviour which is a bad emulation of two + * 16 bit devices making up a 32 bit wide QEMU device. This + * is deprecated for new uses of this device. + */ DEFINE_PROP_UINT8("width", struct pflash_t, bank_width, 0), DEFINE_PROP_UINT8("device-width", struct pflash_t, device_width, 0), + DEFINE_PROP_UINT8("max-device-width", struct pflash_t, max_device_width, 0), DEFINE_PROP_UINT8("big-endian", struct pflash_t, be, 0), DEFINE_PROP_UINT16("id0", struct pflash_t, ident0, 0), DEFINE_PROP_UINT16("id1", struct pflash_t, ident1, 0), |