rockchip: rkimg: Add R/W interfaces for virtual A/B metadata

According to the AOSP default definition, the virtual A/B
metadata is located at the offset 32KB of the misc partition.

Signed-off-by: Dayao Ji <jdy@rock-chips.com>
Change-Id: Ib60379f25e4c72be9f5ed03934ab7dc928cdd585

common/android_ab.c

@@ -10,6 +10,7 @@
 #include <common.h>
 #include <malloc.h>
 #include <u-boot/crc.h>
+#include <boot_rkimg.h>
 
 /** android_boot_control_compute_crc - Compute the CRC-32 of the bootloader
  * control struct. Only the bytes up to the crc32_le field are considered for
@@ -264,3 +265,70 @@ int android_ab_select(struct blk_desc *dev_desc, disk_partition_t *part_info)
 		return -1;
 	return slot;
 }
+
+int read_misc_virtual_ab_message(struct misc_virtual_ab_message *message)
+{
+	struct blk_desc *dev_desc;
+	disk_partition_t part_info;
+	u32 bcb_offset = (ANDROID_VIRTUAL_AB_METADATA_OFFSET_IN_MISC >> 9);
+	int cnt, ret;
+
+	if (!message) {
+		debug("%s: message is NULL!\n", __func__);
+		return -1;
+	}
+
+	dev_desc = rockchip_get_bootdev();
+	if (!dev_desc) {
+		debug("%s: dev_desc is NULL!\n", __func__);
+		return -1;
+	}
+
+	ret = part_get_info_by_name(dev_desc, PART_MISC, &part_info);
+	if (ret < 0) {
+		debug("%s: Could not found misc partition\n",
+		       __func__);
+		return -1;
+	}
+
+	cnt = DIV_ROUND_UP(sizeof(struct misc_virtual_ab_message), dev_desc->blksz);
+	if (blk_dread(dev_desc, part_info.start + bcb_offset, cnt, message) != cnt) {
+		debug("%s: could not read from misc partition\n", __func__);
+		return -1;
+	}
+
+	return 0;
+}
+
+int write_misc_virtual_ab_message(struct misc_virtual_ab_message *message)
+{
+	struct blk_desc *dev_desc;
+	disk_partition_t part_info;
+	u32 bcb_offset = (ANDROID_VIRTUAL_AB_METADATA_OFFSET_IN_MISC >> 9);
+	int cnt, ret;
+
+	if (!message) {
+		debug("%s: message is NULL!\n", __func__);
+		return -1;
+	}
+
+	dev_desc = rockchip_get_bootdev();
+	if (!dev_desc) {
+		debug("%s: dev_desc is NULL!\n", __func__);
+		return -1;
+	}
+
+	ret = part_get_info_by_name(dev_desc, PART_MISC, &part_info);
+	if (ret < 0) {
+		debug("%s: Could not found misc partition\n",
+		       __func__);
+		return -1;
+	}
+
+	cnt = DIV_ROUND_UP(sizeof(struct misc_virtual_ab_message), dev_desc->blksz);
+	ret = blk_dwrite(dev_desc, part_info.start + bcb_offset, cnt, message);
+	if (ret != cnt)
+		debug("%s: blk_dwrite write failed, ret=%d\n", __func__, ret);
+
+	return 0;
+}

include/android_ab.h

@@ -12,6 +12,22 @@
 /* Android standard boot slot names are 'a', 'b', 'c', ... */
 #define ANDROID_BOOT_SLOT_NAME(slot_num) ('a' + (slot_num))
 
+#define ENUM_MERGE_STATUS_NONE			(0)
+#define ENUM_MERGE_STATUS_UNKNOWN		(1)
+#define ENUM_MERGE_STATUS_SNAPSHOTTED		(2)
+#define ENUM_MERGE_STATUS_MERGING		(3)
+#define ENUM_MERGE_STATUS_CANCELLED		(4)
+#define MISC_VIRTUAL_AB_MAGIC_HEADER		(0x56740AB0)
+
+struct misc_virtual_ab_message {
+	u8 version;
+	u32 magic;
+	u8 merge_status;
+	u8 source_slot;
+	u8 reserved[57];
+	u8 reserved2[448];
+} __packed;
+
 /** android_ab_select - Select the slot where to boot from.
  * On Android devices with more than one boot slot (multiple copies of the
  * kernel and system images) selects which slot should be used to boot from and
@@ -27,4 +43,7 @@
  */
 int android_ab_select(struct blk_desc *dev_desc, disk_partition_t *part_info);
 
+/* Read or write the Virtual A/B message from 32KB offset in /misc.*/
+int read_misc_virtual_ab_message(struct misc_virtual_ab_message *message);
+int write_misc_virtual_ab_message(struct misc_virtual_ab_message *message);
 #endif

include/android_bootloader_message.h

@@ -21,12 +21,14 @@
  * 0   - 2K     Bootloader Message
  * 2K  - 16K    Used by Vendor's bootloader (the 2K - 4K range may be optionally used
  *              as bootloader_message_ab struct)
- * 16K - 64K    Used by uncrypt and recovery to store wipe_package for A/B devices
+ * 16K - 32K    Used by uncrypt and recovery to store wipe_package for A/B devices
+ * 32K - 64K    System space, used for miscellaneous AOSP features (virtual A/B metadata).
  * Note that these offsets are admitted by bootloader,recovery and uncrypt, so they
  * are not configurable without changing all of them.
  */
 static const size_t ANDROID_BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
 static const size_t ANDROID_WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
+static const size_t ANDROID_VIRTUAL_AB_METADATA_OFFSET_IN_MISC = 32 * 1024;
 
 /* Bootloader Message (2-KiB)
  *

include/boot_rkimg.h

@@ -59,6 +59,8 @@ struct rockchip_image {
 #define PART_DTBO			"dtbo"
 #define PART_LOGO			"logo"
 #define PART_SYSTEM			"system"
+#define PART_METADATA			"metadata"
+#define PART_USERDATA			"userdata"
 
 struct blk_desc *rockchip_get_bootdev(void);
 void rockchip_set_bootdev(struct blk_desc *desc);