* Re: [PATCH v3 1/1] fastboot: introduce 'oem board' subcommand
2024-04-08 10:15 ` [PATCH v3 1/1] fastboot: introduce 'oem board' subcommand Alexey Romanov
@ 2024-04-09 9:44 ` Mattijs Korpershoek
2024-04-09 14:44 ` Quentin Schulz
1 sibling, 0 replies; 5+ messages in thread
From: Mattijs Korpershoek @ 2024-04-09 9:44 UTC (permalink / raw)
To: Alexey Romanov, sjg, hs, sean.anderson, dimorinny,
patrick.delaunay
Cc: kernel, u-boot, Alexey Romanov
Hi Alexey,
Thank you for the patch.
On lun., avril 08, 2024 at 13:15, Alexey Romanov <avromanov@salutedevices.com> wrote:
> Currently, fastboot protocol in U-Boot has no opportunity
> to execute vendor custom code with verifed boot. This patch
> introduce new fastboot subcommand fastboot oem board:<cmd>,
> which allow to run custom oem_board function.
>
> Default implementation is __weak. Vendor must redefine it in
> board/ folder with his own logic.
>
> For example, some vendors have their custom nand/emmc partition
> flashing or erasing. Here some typical command for such use cases:
>
> - flashing:
>
> $ fastboot stage bootloader.img
> $ fastboot oem board:write_bootloader
>
> - erasing:
>
> $ fastboot oem board:erase_env
>
> Signed-off-by: Alexey Romanov <avromanov@salutedevices.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Thank you for being patient on this topic!
I'll be awaiting 2 more days and will apply to the u-boot-dfu if no
other remarks have been made.
> ---
> doc/android/fastboot.rst | 18 ++++++++++++++++++
> drivers/fastboot/Kconfig | 7 +++++++
> drivers/fastboot/fb_command.c | 30 ++++++++++++++++++++++++++++++
> include/fastboot.h | 1 +
> 4 files changed, 56 insertions(+)
>
> diff --git a/doc/android/fastboot.rst b/doc/android/fastboot.rst
> index 05d8f77759..2020590657 100644
> --- a/doc/android/fastboot.rst
> +++ b/doc/android/fastboot.rst
> @@ -30,6 +30,7 @@ The following OEM commands are supported (if enabled):
> - ``oem bootbus`` - this executes ``mmc bootbus %x %s`` to configure eMMC
> - ``oem run`` - this executes an arbitrary U-Boot command
> - ``oem console`` - this dumps U-Boot console record buffer
> +- ``oem board`` - this executes an custom board function which is defined by vendor
>
> Support for both eMMC and NAND devices is included.
>
> @@ -246,6 +247,23 @@ including multiple commands (using e.g. ``;`` or ``&&``) and control structures
> (``if``, ``while``, etc.). The exit code of ``fastboot`` will reflect the exit
> code of the command you ran.
>
> +Running Custom Vendor Code
> +^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +U-Boot allows you to execute custom fastboot logic, which can be defined
> +in board/ files. It can still be used for production devices with verified
> +boot, because vendor define logic at compile time by overriding weak
> +implementation of fastboot_oem_board() function. The attacker will
> +not able to execute his commands / code. For example, this can be useful
> +for custom flashing or erasing protocols::
> +
> + $ fastboot stage bootloader.img
> + $ fastboot oem board:write_bootloader
> +
> +In this case, ``cmd_parameter`` argument of the function ``fastboot_oem_board()``
> +will contain string "write_bootloader" and ``data`` argument is a pointer to
> +fastboot input buffer, which containing the contents of bootloader.img file.
> +
> References
> ----------
>
> diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
> index 5e5855a76c..937a39f54a 100644
> --- a/drivers/fastboot/Kconfig
> +++ b/drivers/fastboot/Kconfig
> @@ -249,6 +249,13 @@ config FASTBOOT_CMD_OEM_CONSOLE
> Add support for the "oem console" command to input and read console
> record buffer.
>
> +config FASTBOOT_OEM_BOARD
> + bool "Enable the 'oem board' command"
> + help
> + This extends the fastboot protocol with an "oem board" command. This
> + command allows running vendor custom code defined in board/ files.
> + Otherwise, it will do nothing and send fastboot fail.
> +
> endif # FASTBOOT
>
> endmenu
> diff --git a/drivers/fastboot/fb_command.c b/drivers/fastboot/fb_command.c
> index f95f4e4ae1..96c27afc60 100644
> --- a/drivers/fastboot/fb_command.c
> +++ b/drivers/fastboot/fb_command.c
> @@ -42,6 +42,7 @@ static void oem_format(char *, char *);
> static void oem_partconf(char *, char *);
> static void oem_bootbus(char *, char *);
> static void oem_console(char *, char *);
> +static void oem_board(char *, char *);
> static void run_ucmd(char *, char *);
> static void run_acmd(char *, char *);
>
> @@ -113,6 +114,10 @@ static const struct {
> .command = "oem console",
> .dispatch = CONFIG_IS_ENABLED(FASTBOOT_CMD_OEM_CONSOLE, (oem_console), (NULL))
> },
> + [FASTBOOT_COMMAND_OEM_BOARD] = {
> + .command = "oem board",
> + .dispatch = CONFIG_IS_ENABLED(FASTBOOT_OEM_BOARD, (oem_board), (NULL))
> + },
> [FASTBOOT_COMMAND_UCMD] = {
> .command = "UCmd",
> .dispatch = CONFIG_IS_ENABLED(FASTBOOT_UUU_SUPPORT, (run_ucmd), (NULL))
> @@ -542,3 +547,28 @@ static void __maybe_unused oem_console(char *cmd_parameter, char *response)
> else
> fastboot_response(FASTBOOT_MULTIRESPONSE_START, response, NULL);
> }
> +
> +/**
> + * fastboot_oem_board() - Execute the OEM board command. This is default
> + * weak implementation, which may be overwritten in board/ files.
> + *
> + * @cmd_parameter: Pointer to command parameter
> + * @data: Pointer to fastboot input buffer
> + * @size: Size of the fastboot input buffer
> + * @response: Pointer to fastboot response buffer
> + */
> +void __weak fastboot_oem_board(char *cmd_parameter, void *data, u32 size, char *response)
> +{
> + fastboot_fail("oem board function not defined", response);
> +}
> +
> +/**
> + * oem_board() - Execute the OEM board command
> + *
> + * @cmd_parameter: Pointer to command parameter
> + * @response: Pointer to fastboot response buffer
> + */
> +static void __maybe_unused oem_board(char *cmd_parameter, char *response)
> +{
> + fastboot_oem_board(cmd_parameter, fastboot_buf_addr, image_size, response);
> +}
> diff --git a/include/fastboot.h b/include/fastboot.h
> index 1e7920eb91..2ca1b907a5 100644
> --- a/include/fastboot.h
> +++ b/include/fastboot.h
> @@ -48,6 +48,7 @@ enum {
> FASTBOOT_COMMAND_OEM_BOOTBUS,
> FASTBOOT_COMMAND_OEM_RUN,
> FASTBOOT_COMMAND_OEM_CONSOLE,
> + FASTBOOT_COMMAND_OEM_BOARD,
> FASTBOOT_COMMAND_ACMD,
> FASTBOOT_COMMAND_UCMD,
> FASTBOOT_COMMAND_COUNT
> --
> 2.34.1
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v3 1/1] fastboot: introduce 'oem board' subcommand
2024-04-08 10:15 ` [PATCH v3 1/1] fastboot: introduce 'oem board' subcommand Alexey Romanov
2024-04-09 9:44 ` Mattijs Korpershoek
@ 2024-04-09 14:44 ` Quentin Schulz
1 sibling, 0 replies; 5+ messages in thread
From: Quentin Schulz @ 2024-04-09 14:44 UTC (permalink / raw)
To: Alexey Romanov, sjg, hs, sean.anderson, dimorinny, mkorpershoek,
patrick.delaunay
Cc: kernel, u-boot
Hi Alexey,
On 4/8/24 12:15, Alexey Romanov wrote:
> Currently, fastboot protocol in U-Boot has no opportunity
> to execute vendor custom code with verifed boot. This patch
> introduce new fastboot subcommand fastboot oem board:<cmd>,
> which allow to run custom oem_board function.
>
> Default implementation is __weak. Vendor must redefine it in
> board/ folder with his own logic.
>
> For example, some vendors have their custom nand/emmc partition
> flashing or erasing. Here some typical command for such use cases:
>
> - flashing:
>
> $ fastboot stage bootloader.img
> $ fastboot oem board:write_bootloader
>
> - erasing:
>
> $ fastboot oem board:erase_env
>
> Signed-off-by: Alexey Romanov <avromanov@salutedevices.com>
> ---
> doc/android/fastboot.rst | 18 ++++++++++++++++++
> drivers/fastboot/Kconfig | 7 +++++++
> drivers/fastboot/fb_command.c | 30 ++++++++++++++++++++++++++++++
> include/fastboot.h | 1 +
> 4 files changed, 56 insertions(+)
>
> diff --git a/doc/android/fastboot.rst b/doc/android/fastboot.rst
> index 05d8f77759..2020590657 100644
> --- a/doc/android/fastboot.rst
> +++ b/doc/android/fastboot.rst
> @@ -30,6 +30,7 @@ The following OEM commands are supported (if enabled):
> - ``oem bootbus`` - this executes ``mmc bootbus %x %s`` to configure eMMC
> - ``oem run`` - this executes an arbitrary U-Boot command
> - ``oem console`` - this dumps U-Boot console record buffer
> +- ``oem board`` - this executes an custom board function which is defined by vendor
s/an/a/
+the vendor? (missing "the")
>
> Support for both eMMC and NAND devices is included.
>
> @@ -246,6 +247,23 @@ including multiple commands (using e.g. ``;`` or ``&&``) and control structures
> (``if``, ``while``, etc.). The exit code of ``fastboot`` will reflect the exit
> code of the command you ran.
>
> +Running Custom Vendor Code
> +^^^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +U-Boot allows you to execute custom fastboot logic, which can be defined
> +in board/ files. It can still be used for production devices with verified
> +boot, because vendor define logic at compile time by overriding weak
s/vendor define/the vendor defines/
Suggestion:
Replace "by overriding weak implementation of fastboot_oem_board()" with
"by implementing fastboot_oem_board()", the weak symbol is an
implementation detail I don't think we need to keep in the documentation?
> +implementation of fastboot_oem_board() function. The attacker will
> +not able to execute his commands / code. For example, this can be useful
+be able (missing be)
s/his/custom/ or s/his/their/
> +for custom flashing or erasing protocols::
> +
> + $ fastboot stage bootloader.img
> + $ fastboot oem board:write_bootloader
> +
> +In this case, ``cmd_parameter`` argument of the function ``fastboot_oem_board()``
> +will contain string "write_bootloader" and ``data`` argument is a pointer to
> +fastboot input buffer, which containing the contents of bootloader.img file.
> +
Either
-which (remove "which")
s/which containing/which contains/
Cheers,
Quentin
^ permalink raw reply [flat|nested] 5+ messages in thread