diff --git a/hw/sd/sdmmc-internal.h b/hw/sd/sdmmc-internal.h
index d8bf17d..7ab7b4d 100644
--- a/hw/sd/sdmmc-internal.h
+++ b/hw/sd/sdmmc-internal.h
@@ -37,4 +37,101 @@ const char *sd_cmd_name(uint8_t cmd);
  */
 const char *sd_acmd_name(uint8_t cmd);
 
+/*
+ * EXT_CSD fields
+ */
+
+#define EXT_CSD_CMDQ_MODE_EN    15  /* R/W */
+#define EXT_CSD_FLUSH_CACHE   32      /* W */
+#define EXT_CSD_CACHE_CTRL    33      /* R/W */
+#define EXT_CSD_POWER_OFF_NOTIFICATION  34  /* R/W */
+#define EXT_CSD_PACKED_FAILURE_INDEX  35  /* RO */
+#define EXT_CSD_PACKED_CMD_STATUS 36  /* RO */
+#define EXT_CSD_EXP_EVENTS_STATUS 54  /* RO, 2 bytes */
+#define EXT_CSD_EXP_EVENTS_CTRL   56  /* R/W, 2 bytes */
+#define EXT_CSD_DATA_SECTOR_SIZE  61  /* R */
+#define EXT_CSD_GP_SIZE_MULT    143 /* R/W */
+#define EXT_CSD_PARTITION_SETTING_COMPLETED 155 /* R/W */
+#define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */
+#define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
+#define EXT_CSD_HPI_MGMT    161 /* R/W */
+#define EXT_CSD_RST_N_FUNCTION    162 /* R/W */
+#define EXT_CSD_BKOPS_EN    163 /* R/W */
+#define EXT_CSD_BKOPS_START   164 /* W */
+#define EXT_CSD_SANITIZE_START    165     /* W */
+#define EXT_CSD_WR_REL_PARAM    166 /* RO */
+#define EXT_CSD_RPMB_MULT   168 /* RO */
+#define EXT_CSD_FW_CONFIG   169 /* R/W */
+#define EXT_CSD_BOOT_WP     173 /* R/W */
+#define EXT_CSD_ERASE_GROUP_DEF   175 /* R/W */
+#define EXT_CSD_PART_CONFIG   179 /* R/W */
+#define EXT_CSD_ERASED_MEM_CONT   181 /* RO */
+#define EXT_CSD_BUS_WIDTH   183 /* R/W */
+#define EXT_CSD_STROBE_SUPPORT    184 /* RO */
+#define EXT_CSD_HS_TIMING   185 /* R/W */
+#define EXT_CSD_POWER_CLASS   187 /* R/W */
+#define EXT_CSD_REV     192 /* RO */
+#define EXT_CSD_STRUCTURE   194 /* RO */
+#define EXT_CSD_CARD_TYPE   196 /* RO */
+#define EXT_CSD_DRIVER_STRENGTH   197 /* RO */
+#define EXT_CSD_OUT_OF_INTERRUPT_TIME 198 /* RO */
+#define EXT_CSD_PART_SWITCH_TIME        199     /* RO */
+#define EXT_CSD_PWR_CL_52_195   200 /* RO */
+#define EXT_CSD_PWR_CL_26_195   201 /* RO */
+#define EXT_CSD_PWR_CL_52_360   202 /* RO */
+#define EXT_CSD_PWR_CL_26_360   203 /* RO */
+#define EXT_CSD_SEC_CNT     212 /* RO, 4 bytes */
+#define EXT_CSD_S_A_TIMEOUT   217 /* RO */
+#define EXT_CSD_S_C_VCCQ          219     /* RO */
+#define EXT_CSD_S_C_VCC                 220     /* RO */
+#define EXT_CSD_REL_WR_SEC_C    222 /* RO */
+#define EXT_CSD_HC_WP_GRP_SIZE    221 /* RO */
+#define EXT_CSD_ERASE_TIMEOUT_MULT  223 /* RO */
+#define EXT_CSD_HC_ERASE_GRP_SIZE 224 /* RO */
+#define EXT_CSD_ACC_SIZE    225 /* RO */
+#define EXT_CSD_BOOT_MULT   226 /* RO */
+#define EXT_CSD_BOOT_INFO   228 /* RO */
+#define EXT_CSD_SEC_TRIM_MULT   229 /* RO */
+#define EXT_CSD_SEC_ERASE_MULT    230 /* RO */
+#define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */
+#define EXT_CSD_TRIM_MULT   232 /* RO */
+#define EXT_CSD_PWR_CL_200_195    236 /* RO */
+#define EXT_CSD_PWR_CL_200_360    237 /* RO */
+#define EXT_CSD_PWR_CL_DDR_52_195 238 /* RO */
+#define EXT_CSD_PWR_CL_DDR_52_360 239 /* RO */
+#define EXT_CSD_BKOPS_STATUS    246 /* RO */
+#define EXT_CSD_POWER_OFF_LONG_TIME 247 /* RO */
+#define EXT_CSD_GENERIC_CMD6_TIME 248 /* RO */
+#define EXT_CSD_CACHE_SIZE    249 /* RO, 4 bytes */
+#define EXT_CSD_PWR_CL_DDR_200_360  253 /* RO */
+#define EXT_CSD_FIRMWARE_VERSION  254 /* RO, 8 bytes */
+#define EXT_CSD_PRE_EOL_INFO    267 /* RO */
+#define EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A  268 /* RO */
+#define EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B  269 /* RO */
+#define EXT_CSD_CMDQ_DEPTH    307 /* RO */
+#define EXT_CSD_CMDQ_SUPPORT    308 /* RO */
+#define EXT_CSD_SUPPORTED_MODE    493 /* RO */
+#define EXT_CSD_TAG_UNIT_SIZE   498 /* RO */
+#define EXT_CSD_DATA_TAG_SUPPORT  499 /* RO */
+#define EXT_CSD_MAX_PACKED_WRITES 500 /* RO */
+#define EXT_CSD_MAX_PACKED_READS  501 /* RO */
+#define EXT_CSD_BKOPS_SUPPORT   502 /* RO */
+#define EXT_CSD_HPI_FEATURES    503 /* RO */
+#define EXT_CSD_S_CMD_SET   504 /* RO */
+
+/*
+ * EXT_CSD field definitions
+ */
+
+#define EXT_CSD_WR_REL_PARAM_EN   (1 << 2)
+#define EXT_CSD_WR_REL_PARAM_EN_RPMB_REL_WR (1 << 4)
+
+#define EXT_CSD_PART_CONFIG_ACC_MASK  (0x7)
+#define EXT_CSD_PART_CONFIG_ACC_DEFAULT (0x0)
+#define EXT_CSD_PART_CONFIG_ACC_BOOT0 (0x1)
+
+#define EXT_CSD_PART_CONFIG_EN_MASK (0x7 << 3)
+#define EXT_CSD_PART_CONFIG_EN_BOOT0  (0x1 << 3)
+#define EXT_CSD_PART_CONFIG_EN_USER (0x7 << 3)
+
 #endif
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index bc9d913..a26695b 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -135,6 +135,7 @@ struct SDState {
     uint64_t data_start;
     uint32_t data_offset;
     uint8_t data[512];
+    uint8_t ext_csd[512];
     qemu_irq readonly_cb;
     qemu_irq inserted_cb;
     QEMUTimer *ocr_power_timer;
@@ -393,6 +394,55 @@ static const uint8_t sd_csd_rw_mask[16] = {
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfc, 0xfe,
 };
 
+static void mmc_set_ext_csd(SDState *sd, uint64_t size)
+{
+    uint32_t sectcount = size >> HWBLOCK_SHIFT;
+
+    memset(sd->ext_csd, 0, sizeof(sd->ext_csd));
+    sd->ext_csd[EXT_CSD_S_CMD_SET] = 0x1; /* supported command sets */
+    sd->ext_csd[EXT_CSD_HPI_FEATURES] = 0x3; /* HPI features  */
+    sd->ext_csd[EXT_CSD_BKOPS_SUPPORT] = 0x1; /* Background operations
+                                                 support */
+    sd->ext_csd[241] = 0xA; /* 1st initialization time after partitioning */
+    sd->ext_csd[EXT_CSD_TRIM_MULT] = 0x1; /* Trim multiplier */
+    sd->ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT] = 0x15; /* Secure feature
+                                                        support */
+    sd->ext_csd[EXT_CSD_SEC_ERASE_MULT] = 0x96; /* Secure erase support */
+    sd->ext_csd[EXT_CSD_SEC_TRIM_MULT] = 0x96; /* Secure TRIM multiplier */
+    sd->ext_csd[EXT_CSD_BOOT_INFO] = 0x7; /* Boot information */
+    sd->ext_csd[EXT_CSD_BOOT_MULT] = 0x8; /* Boot partition size. 128KB unit */
+    sd->ext_csd[EXT_CSD_ACC_SIZE] = 0x6; /* Access size */
+    sd->ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] = 0x4; /* HC Erase unit size */
+    sd->ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT] = 0x1; /* HC erase timeout */
+    sd->ext_csd[EXT_CSD_REL_WR_SEC_C] = 0x1; /* Reliable write sector count */
+    sd->ext_csd[EXT_CSD_HC_WP_GRP_SIZE] = 0x4; /* HC write protect group size */
+    sd->ext_csd[EXT_CSD_S_C_VCC] = 0x8; /* Sleep current VCC  */
+    sd->ext_csd[EXT_CSD_S_C_VCCQ] = 0x7; /* Sleep current VCCQ */
+    sd->ext_csd[EXT_CSD_S_A_TIMEOUT] = 0x11; /* Sleep/Awake timeout */
+    sd->ext_csd[215] = (sectcount >> 24) & 0xff; /* Sector count */
+    sd->ext_csd[214] = (sectcount >> 16) & 0xff; /* ... */
+    sd->ext_csd[213] = (sectcount >> 8) & 0xff;  /* ... */
+    sd->ext_csd[EXT_CSD_SEC_CNT] = (sectcount & 0xff);       /* ... */
+    sd->ext_csd[210] = 0xa; /* Min write perf for 8bit@52Mhz */
+    sd->ext_csd[209] = 0xa; /* Min read perf for 8bit@52Mhz  */
+    sd->ext_csd[208] = 0xa; /* Min write perf for 4bit@52Mhz */
+    sd->ext_csd[207] = 0xa; /* Min read perf for 4bit@52Mhz */
+    sd->ext_csd[206] = 0xa; /* Min write perf for 4bit@26Mhz */
+    sd->ext_csd[205] = 0xa; /* Min read perf for 4bit@26Mhz */
+    sd->ext_csd[EXT_CSD_PART_SWITCH_TIME] = 0x1; /* Partition switching
+                                                    timing */
+    sd->ext_csd[EXT_CSD_OUT_OF_INTERRUPT_TIME] = 0x1; /* Out-of-interrupt busy
+                                                         timing */
+    sd->ext_csd[EXT_CSD_CARD_TYPE] = 0xFF; /* Card type */
+    sd->ext_csd[EXT_CSD_STRUCTURE] = 0x2; /* CSD Structure version */
+    sd->ext_csd[EXT_CSD_REV] = 0x5; /* Extended CSD revision */
+    sd->ext_csd[EXT_CSD_RPMB_MULT] = 0x1; /* RPMB size */
+    sd->ext_csd[EXT_CSD_PARTITION_SUPPORT] = 0x3; /* Partinioning support */
+    sd->ext_csd[159] = 0x00; /* Max enhanced area size */
+    sd->ext_csd[158] = 0x00; /* ... */
+    sd->ext_csd[157] = 0xEC; /* ... */
+}
+
 static void sd_set_csd(SDState *sd, uint64_t size)
 {
     int hwblock_shift = HWBLOCK_SHIFT;
@@ -406,8 +456,11 @@ static void sd_set_csd(SDState *sd, uint64_t size)
     }
     csize = (size >> (CMULT_SHIFT + hwblock_shift)) - 1;
 
-    if (size <= SDSC_MAX_CAPACITY) { /* Standard Capacity SD */
-        sd->csd[0] = 0x00;  /* CSD structure */
+    if (size <= SDSC_MAX_CAPACITY || sd->emmc) { /* Standard Capacity SD */
+        if (sd->emmc && size >= SDSC_MAX_CAPACITY) {
+            csize = 0xfff;
+        }
+        sd->csd[0] = sd->emmc ? 0xd0 : 0x00;  /* CSD structure */
         sd->csd[1] = 0x26;  /* Data read access-time-1 */
         sd->csd[2] = 0x00;  /* Data read access-time-2 */
         sd->csd[3] = 0x32;      /* Max. data transfer rate: 25 MHz */
@@ -451,6 +504,10 @@ static void sd_set_csd(SDState *sd, uint64_t size)
         sd->csd[14] = 0x00;
     }
     sd->csd[15] = (sd_crc7(sd->csd, 15) << 1) | 1;
+
+    if (sd->emmc) {
+        mmc_set_ext_csd(sd, size);
+    }
 }
 
 static void sd_set_rca(SDState *sd, uint16_t value)
