sdcard: add support for spi sdcard driver

sdcard/cid.go

@@ -0,0 +1,49 @@
+package sdcard
+
+import "fmt"
+
+type CID struct {
+	//// byte 0
+	ManufacturerID byte
+	//uint8_t mid;  // Manufacturer ID
+	//// byte 1-2
+	OEMApplicationID uint16
+	//char oid[2];  // OEM/Application ID
+	//// byte 3-7
+	ProductName string
+	//char pnm[5];  // Product name
+	//// byte 8
+	ProductVersion string
+	//unsigned prv_m : 4;  // Product revision n.m
+	//unsigned prv_n : 4;
+	//// byte 9-12
+	ProductSerialNumber uint32
+	//uint32_t psn;  // Product serial number
+	//// byte 13
+	ManufacturingYear  byte
+	ManufacturingMonth byte
+	//unsigned mdt_year_high : 4;  // Manufacturing date
+	//unsigned reserved : 4;
+	//// byte 14
+	//unsigned mdt_month : 4;
+	//unsigned mdt_year_low : 4;
+	//// byte 15
+	Always1 byte
+	//unsigned always1 : 1;
+	CRC byte
+	//unsigned crc : 7;
+}
+
+func NewCID(buf []byte) *CID {
+	return &CID{
+		ManufacturerID:      buf[0],
+		OEMApplicationID:    (uint16(buf[0]) << 8) | uint16(buf[1]),
+		ProductName:         string(buf[3:8]),
+		ProductVersion:      fmt.Sprintf("%d.%d", (buf[8]&0xF0)>>4, buf[8]&0x0F),
+		ProductSerialNumber: (uint32(buf[9]) << 24) | (uint32(buf[10]) << 16) | (uint32(buf[11]) << 8) | uint32(buf[12]),
+		ManufacturingYear:   (buf[13] & 0xF0) | (buf[14] & 0x0F),
+		ManufacturingMonth:  (buf[14] & 0xF0) >> 4,
+		Always1:             (buf[15] & 0x80) >> 7,
+		CRC:                 buf[15] & 0x7F,
+	}
+}