[PATCH v47 13/19] hw/sd/sdcard: Migrate ExtCSD 'modes' register

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Spec v4.3, chapter 8.4 "Extended CSD register":

  The Extended CSD register defines the card properties
  and selected modes. It is 512 bytes long. The most
  significant 320 bytes are the Properties segment, which
  defines the card capabilities and cannot be modified by
  the host. The lower 192 bytes are the Modes segment,
  which defines the configuration the card is working in.

Only migrate the Modes segment (192 lower bytes).

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/sd/sd.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 2a687977d1..a391f12b2a 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -124,7 +124,13 @@ struct SDState {
     uint16_t rca;
     uint32_t card_status;
     uint8_t sd_status[64];
-    uint8_t ext_csd[512];
+    union {
+        uint8_t ext_csd[512];
+        struct {
+            uint8_t ext_csd_rw[192]; /* Modes segment */
+            uint8_t ext_csd_ro[320]; /* Properties segment */
+        };
+    };
 
     /* Static properties */
 
@@ -881,6 +887,24 @@ static const VMStateDescription sd_ocr_vmstate = {
     },
 };
 
+static bool vmstate_needed_for_emmc(void *opaque)
+{
+    SDState *sd = opaque;
+
+    return sd_is_emmc(sd);
+}
+
+static const VMStateDescription emmc_extcsd_vmstate = {
+    .name = "sd-card/ext_csd_modes-state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = vmstate_needed_for_emmc,
+    .fields = (const VMStateField[]) {
+        VMSTATE_UINT8_ARRAY(ext_csd_rw, SDState, 192),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static int sd_vmstate_pre_load(void *opaque)
 {
     SDState *sd = opaque;
@@ -928,6 +952,7 @@ static const VMStateDescription sd_vmstate = {
     },
     .subsections = (const VMStateDescription * const []) {
         &sd_ocr_vmstate,
+        &emmc_extcsd_vmstate,
         NULL
     },
 };
-- 
2.41.0