[v5,4/5] hw/block/pflash_cfi01: Start state machine as READY to accept commands
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Message ID 20190715121338.20600-5-philmd@redhat.com
State New
Headers show
  • hw/block/pflash_cfi01: Add DeviceReset() handler
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Commit Message

Philippe Mathieu-Daudé July 15, 2019, 12:13 p.m. UTC
When the state machine is ready to accept command, the bit 7 of
the status register (SR) is set to 1.
The guest polls the status register and check this bit before
writting command to the internal 'Write State Machine' (WSM).

Set SR.7 bit to 1 when the device is created.

There is no migration impact by this change.

Reference: Read Array Flowchart
  "Common Flash Interface (CFI) and Command Sets"
   (Intel Application Note 646)
   Appendix B "Basic Command Set"

Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
v3: Added migration comment.
 hw/block/pflash_cfi01.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff mbox series

diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 6c3fefcd2d..aa2126f6dc 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -796,7 +796,7 @@  static void pflash_cfi01_realize(DeviceState *dev, Error **errp)
-    pfl->status = 0;
+    pfl->status = 0x80; /* WSM ready */
     /* Hardcoded CFI table */
     /* Standard "QRY" string */
     pfl->cfi_table[0x10] = 'Q';