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

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(+)

On Wed, May 27, 2020 at 12:14 PM Roman Kovalivskyi
<roman.kovalivskyi at globallogic.com> wrote:
>
> 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;

I've not been keeping up with where fastboot has been going, but this
feels ugly in common code.

> +#else
> +       return -ENOSYS;
> +#endif
> +}
> +
>  /**
>   * fastboot_get_progress_callback() - Return progress callback
>   *

Should fastboot_set_flag/fastboot_set_reboot_flag be consolidated into
a single interface?

> 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;
>                 }

I expect you need a similar change in net/fastboot.c:fastboot_send (a
piece of ugliness I failed to abstract away when redoing this).

> 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
>