[Qemu-devel] [PATCH 17/20] sdcard: Add SDFrameData struct and data frame checksum functions

[Philippe Mathieu-Daudé]

The block transfers data frames are upto 512 bytes and use a 16-bit CRC.

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 include/hw/sd/sd.h     | 29 +++++++++++++++++++++++++++++
 hw/sd/sdmmc-internal.c | 10 ++++++++++
 2 files changed, 39 insertions(+)

diff --git a/include/hw/sd/sd.h b/include/hw/sd/sd.h
index c76be51b32..6bf9daf559 100644
--- a/include/hw/sd/sd.h
+++ b/include/hw/sd/sd.h
@@ -102,6 +102,17 @@ typedef struct SDFrame136 {
     uint8_t crc;
 } SDFrame136;
 
+/**
+ * SDFrameData: 512 bytes block transfers
+ *
+ * @content: block data
+ * @crc:     16-bit CRC checksum
+ */
+typedef struct SDFrameData {
+    uint8_t content[512];
+    uint16_t crc;
+} SDFrameData;
+
 typedef struct SDFrame48 SDRequest;
 
 typedef struct SDState SDState;
@@ -212,6 +223,14 @@ void sd_update_frame48_checksum(SDFrame48 *frame, bool 
is_response);
  */
 void sd_update_frame136_checksum(SDFrame136 *frame);
 
+/**
+ * sd_update_framedata_checksum:
+ * @frame: the #SDFrameData to verify
+ *
+ * Update the 16-bit CRC checksum of a SD data frame (up to 512 bytes).
+ */
+void sd_update_framedata_checksum(SDFrameData *frame);
+
 /**
  * sd_verify_frame48_checksum:
  * @frame: the #SDFrame48 to verify
@@ -233,6 +252,16 @@ bool sd_verify_frame48_checksum(SDFrame48 *frame, bool 
is_response);
  */
 bool sd_verify_frame136_checksum(SDFrame136 *frame);
 
+/**
+ * sd_verify_framedata_checksum:
+ * @frame: the #SDFrameData to verify
+ *
+ * Verify the 16-bit CRC checksum of a SD data frame.
+ *
+ * Returns: A boolean indicating whether the frame 16-bit CRC is correct.
+ */
+bool sd_verify_framedata_checksum(SDFrameData *frame);
+
 /* Legacy functions to be used only by non-qdevified callers */
 SDState *sd_init(BlockBackend *bs, bool is_spi);
 int sd_do_command(SDState *sd, SDRequest *req,
diff --git a/hw/sd/sdmmc-internal.c b/hw/sd/sdmmc-internal.c
index 68350a2304..0e82e69d99 100644
--- a/hw/sd/sdmmc-internal.c
+++ b/hw/sd/sdmmc-internal.c
@@ -134,6 +134,11 @@ bool sd_verify_frame136_checksum(SDFrame136 *frame)
     return sd_calc_frame136_crc7(frame) == frame->crc;
 }
 
+bool sd_verify_framedata_checksum(SDFrameData *frame)
+{
+    return sd_crc16(frame->content, sizeof(frame->content)) == frame->crc;
+}
+
 void sd_update_frame48_checksum(SDFrame48 *frame, bool is_response)
 {
     frame->crc = sd_calc_frame48_crc7(frame->cmd, frame->arg, is_response);
@@ -144,6 +149,11 @@ void sd_update_frame136_checksum(SDFrame136 *frame)
     frame->crc = (sd_crc7(frame->content, sizeof(frame->content)) << 1) | 1;
 }
 
+void sd_update_framedata_checksum(SDFrameData *frame)
+{
+    frame->crc = sd_crc16(frame->content, sizeof(frame->content));
+}
+
 void sd_prepare_frame48(SDFrame48 *frame, uint8_t cmd, uint32_t arg,
                         bool is_response, bool gen_crc)
 {
-- 
2.17.0