[PATCH 1/1] fastboot: add support for 'reboot fastboot' command

[Roman Kovalivskyi]

From: Roman Stratiienko <r.stratiienko at gmail.com>

Android 10 adds support for dynamic partitions and in order to support
them userspace fastboot must be used[1]. New tool fastbootd is
included into recovery image.

Userspace fastboot works from recovery and is launched if:
1) - Dynamic partitioning is enabled
2) - Boot control block has 'boot-fastboot' value into command field
The bootloader is expected to load and boot into the recovery image
upon seeing boot-fastboot in the BCB command. Recovery then parses the
BCB message and switches to fastbootd mode[2].

Please note that boot script is expected to handle 'boot-fastboot'
command in BCB and load into recovery mode.

Bootloader must support 'reboot fastboot' command which should reboot
device into userspace fastboot to accomodate those changes[3].

[1] - https://source.android.com/devices/bootloader/fastbootd
[2] - https://source.android.com/devices/bootloader/fastbootd#unified_fastboot_and_recovery
[3] - https://source.android.com/devices/bootloader/fastbootd#modifications_to_the_bootloader

Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi at globallogic.com>
Signed-off-by: Roman Stratiienko <r.stratiienko at gmail.com>
Change-Id: I9d2bdc9a6f6f31ea98572fe155e1cc8341e9af76
---
 drivers/fastboot/fb_command.c   | 42 +++++++++++++++++++++++++++++++++
 drivers/fastboot/fb_common.c    | 31 ++++++++++++++++++++++++
 drivers/usb/gadget/f_fastboot.c |  2 ++
 include/fastboot.h              |  9 +++++++
 4 files changed, 84 insertions(+)

diff --git a/drivers/fastboot/fb_command.c b/drivers/fastboot/fb_command.c
index 49f6a61c3745..3616133b880e 100644
--- a/drivers/fastboot/fb_command.c
+++ b/drivers/fastboot/fb_command.c
@@ -37,6 +37,8 @@ static void flash(char *, char *);
 static void erase(char *, char *);
 #endif
 static void reboot_bootloader(char *, char *);
+static void reboot_fastbootd(char *, char *);
+static void reboot_recovery(char *, char *);
 #if CONFIG_IS_ENABLED(FASTBOOT_CMD_OEM_FORMAT)
 static void oem_format(char *, char *);
 #endif
@@ -79,6 +81,14 @@ static const struct {
 		.command = "reboot-bootloader",
 		.dispatch = reboot_bootloader
 	},
+	[FASTBOOT_COMMAND_REBOOT_FASTBOOTD] =  {
+		.command = "reboot-fastboot",
+		.dispatch = reboot_fastbootd
+	},
+	[FASTBOOT_COMMAND_REBOOT_RECOVERY] =  {
+		.command = "reboot-recovery",
+		.dispatch = reboot_recovery
+	},
 	[FASTBOOT_COMMAND_SET_ACTIVE] =  {
 		.command = "set_active",
 		.dispatch = okay
@@ -307,12 +317,44 @@ static void erase(char *cmd_parameter, char *response)
  */
 static void reboot_bootloader(char *cmd_parameter, char *response)
 {
+#if CONFIG_IS_ENABLED(CMD_BCB)
+	if (fastboot_set_flag("bootonce-bootloader"))
+#else
 	if (fastboot_set_reboot_flag())
+#endif
 		fastboot_fail("Cannot set reboot flag", response);
 	else
 		fastboot_okay(NULL, response);
 }
 
+/**
+ * reboot_fastbootd() - Sets reboot fastboot flag.
+ *
+ * @cmd_parameter: Pointer to command parameter
+ * @response: Pointer to fastboot response buffer
+ */
+static void reboot_fastbootd(char *cmd_parameter, char *response)
+{
+	if (fastboot_set_flag("boot-fastboot"))
+		fastboot_fail("Cannot set fastboot flag", response);
+	else
+		fastboot_okay(NULL, response);
+}
+
+/**
+ * reboot_recovery() - Sets reboot recovery flag.
+ *
+ * @cmd_parameter: Pointer to command parameter
+ * @response: Pointer to fastboot response buffer
+ */
+static void reboot_recovery(char *cmd_parameter, char *response)
+{
+	if (fastboot_set_flag("boot-recovery"))
+		fastboot_fail("Cannot set recovery flag", response);
+	else
+		fastboot_okay(NULL, response);
+}
+
 #if CONFIG_IS_ENABLED(FASTBOOT_CMD_OEM_FORMAT)
 /**
  * oem_format() - Execute the OEM format command
diff --git a/drivers/fastboot/fb_common.c b/drivers/fastboot/fb_common.c
index c3735a44af74..b6401640ad06 100644
--- a/drivers/fastboot/fb_common.c
+++ b/drivers/fastboot/fb_common.c
@@ -93,6 +93,37 @@ int __weak fastboot_set_reboot_flag(void)
 	return -ENOSYS;
 }
 
+/**
+ * fastboot_set_flag() - Set flag to indicate reboot-recovery
+ *
+ * Set flag which indicates that we should reboot into the recovery
+ * following the reboot that fastboot executes after this function.
+ */
+int fastboot_set_flag(const char *command)
+{
+#if CONFIG_IS_ENABLED(CMD_BCB)
+	char cmd[32];
+
+	snprintf(cmd, sizeof(cmd), "bcb load %d misc",
+		 CONFIG_FASTBOOT_FLASH_MMC_DEV);
+
+	if (run_command(cmd, 0))
+		return -ENODEV;
+
+	snprintf(cmd, sizeof(cmd), "bcb set command %s", command);
+
+	if (run_command(cmd, 0))
+		return -ENOEXEC;
+
+	if (run_command("bcb store", 0))
+		return -EIO;
+
+	return 0;
+#else
+	return -ENOSYS;
+#endif
+}
+
 /**
  * fastboot_get_progress_callback() - Return progress callback
  *
diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index 384c0f6f6e27..30f7a52087fc 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -455,6 +455,8 @@ static void rx_handler_command(struct usb_ep *ep, struct usb_request *req)
 
 		case FASTBOOT_COMMAND_REBOOT:
 		case FASTBOOT_COMMAND_REBOOT_BOOTLOADER:
+		case FASTBOOT_COMMAND_REBOOT_FASTBOOTD:
+		case FASTBOOT_COMMAND_REBOOT_RECOVERY:
 			fastboot_func->in_req->complete = compl_do_reset;
 			break;
 		}
diff --git a/include/fastboot.h b/include/fastboot.h
index 1933b1d98e3b..8fd2a9e49d0f 100644
--- a/include/fastboot.h
+++ b/include/fastboot.h
@@ -32,6 +32,8 @@ enum {
 	FASTBOOT_COMMAND_CONTINUE,
 	FASTBOOT_COMMAND_REBOOT,
 	FASTBOOT_COMMAND_REBOOT_BOOTLOADER,
+	FASTBOOT_COMMAND_REBOOT_FASTBOOTD,
+	FASTBOOT_COMMAND_REBOOT_RECOVERY,
 	FASTBOOT_COMMAND_SET_ACTIVE,
 #if CONFIG_IS_ENABLED(FASTBOOT_CMD_OEM_FORMAT)
 	FASTBOOT_COMMAND_OEM_FORMAT,
@@ -79,6 +81,13 @@ void fastboot_okay(const char *reason, char *response);
  */
 int fastboot_set_reboot_flag(void);
 
+/**
+ * fastboot_set_flag() - Set flag to indicate reboot-fastboot
+ *
+ * Set flag which indicates that system should reboot into specified mode.
+ */
+int fastboot_set_flag(const char *command);
+
 /**
  * fastboot_set_progress_callback() - set progress callback
  *
-- 
2.17.1