[RFC PATCH 12/15] sd: emmc: Support boot area in emmc image

[Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>]

From: Joel Stanley <joel@jms.id.au>

This assumes a specially constructued image:

  dd if=/dev/zero of=mmc-bootarea.img count=2 bs=1M
  dd if=u-boot-spl.bin of=mmc-bootarea.img conv=notrunc
  dd if=u-boot.bin of=mmc-bootarea.img conv=notrunc count=64 bs=1K
  cat mmc-bootarea.img obmc-phosphor-image.wic > mmc.img
  truncate --size 16GB mmc.img
  truncate --size 128MB mmc-bootarea.img

Signed-off-by: Joel Stanley <joel@jms.id.au>
[clg: - changes on the definition names ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
[spb: use data_start property to access right emmc partition,
      Clean up PARTITION_ENABLE support as incomplete,
      Fix commit message to be generic.]
Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
---
 hw/sd/sd.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 54fba7b..55c1104 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1045,6 +1045,34 @@ static void sd_lock_command(SDState *sd)
         sd->card_status &= ~CARD_IS_LOCKED;
 }
 
+/*
+ * This requires a disk image that has two boot partitions inserted at the
+ * beginning of it. The size of the boot partitions are configured in the
+ * ext_csd structure, which is hardcoded in qemu. They are currently set to
+ * 1MB each.
+ */
+static uint32_t sd_bootpart_offset(SDState *sd)
+{
+    unsigned int access = sd->ext_csd[EXT_CSD_PART_CONFIG] &
+        EXT_CSD_PART_CONFIG_ACC_MASK;
+    unsigned int boot_capacity = sd->ext_csd[EXT_CSD_BOOT_MULT] << 17;
+
+    if (!sd->emmc) {
+        return 0;
+    }
+
+    switch (access) {
+    case EXT_CSD_PART_CONFIG_ACC_DEFAULT:
+        return boot_capacity * 2;
+    case EXT_CSD_PART_CONFIG_ACC_BOOT0:
+        return 0;
+    case EXT_CSD_PART_CONFIG_ACC_BOOT0 + 1:
+        return boot_capacity * 1;
+    default:
+         g_assert_not_reached();
+    }
+}
+
 static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
 {
     uint32_t rca = 0x0000;
@@ -1360,6 +1388,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
                 return sd_r1;
             }
 
+            if (sd->emmc) {
+                addr += sd_bootpart_offset(sd);
+            }
             sd->state = sd_sendingdata_state;
             sd->data_start = addr;
             sd->data_offset = 0;
@@ -1379,6 +1410,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
                 return sd_r1;
             }
 
+            if (sd->emmc) {
+                addr += sd_bootpart_offset(sd);
+            }
             sd->state = sd_sendingdata_state;
             sd->data_start = addr;
             sd->data_offset = 0;
@@ -1435,6 +1469,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
                 return sd_r1;
             }
 
+            if (sd->emmc) {
+                addr += sd_bootpart_offset(sd);
+            }
             sd->state = sd_receivingdata_state;
             sd->data_start = addr;
             sd->data_offset = 0;
@@ -1465,6 +1502,9 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
                 return sd_r1;
             }
 
+            if (sd->emmc) {
+                addr += sd_bootpart_offset(sd);
+            }
             sd->state = sd_receivingdata_state;
             sd->data_start = addr;
             sd->data_offset = 0;
-- 
2.7.4