[RFC PATCH v2 1/2] fastboot: introduce 'oem board' subcommand

[Alexey Romanov]

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 at salutedevices.com>
---
 drivers/fastboot/Kconfig      |  7 +++++++
 drivers/fastboot/fb_command.c | 15 +++++++++++++++
 include/fastboot.h            |  1 +
 3 files changed, 23 insertions(+)

diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
index a4313d60a9..4d94391a76 100644
--- a/drivers/fastboot/Kconfig
+++ b/drivers/fastboot/Kconfig
@@ -241,6 +241,13 @@ config FASTBOOT_OEM_RUN
 	  this feature if you are using verified boot, as it will allow an
 	  attacker to bypass any restrictions you have in place.
 
+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 5fcadcdf50..2298815770 100644
--- a/drivers/fastboot/fb_command.c
+++ b/drivers/fastboot/fb_command.c
@@ -40,6 +40,7 @@ static void reboot_recovery(char *, char *);
 static void oem_format(char *, char *);
 static void oem_partconf(char *, char *);
 static void oem_bootbus(char *, char *);
+static void oem_board(char *, char *);
 static void run_ucmd(char *, char *);
 static void run_acmd(char *, char *);
 
@@ -107,6 +108,10 @@ static const struct {
 		.command = "oem run",
 		.dispatch = CONFIG_IS_ENABLED(FASTBOOT_OEM_RUN, (run_ucmd), (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))
@@ -490,3 +495,13 @@ static void __maybe_unused oem_bootbus(char *cmd_parameter, char *response)
 	else
 		fastboot_okay(NULL, response);
 }
+
+void __weak fastboot_oem_board(char *cmd_parameter, void *data, u32 size, char *response)
+{
+	fastboot_fail("oem board function not defined", response);
+}
+
+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 296451f89d..06c1f26b6c 100644
--- a/include/fastboot.h
+++ b/include/fastboot.h
@@ -37,6 +37,7 @@ enum {
 	FASTBOOT_COMMAND_OEM_PARTCONF,
 	FASTBOOT_COMMAND_OEM_BOOTBUS,
 	FASTBOOT_COMMAND_OEM_RUN,
+	FASTBOOT_COMMAND_OEM_BOARD,
 	FASTBOOT_COMMAND_ACMD,
 	FASTBOOT_COMMAND_UCMD,
 	FASTBOOT_COMMAND_COUNT
-- 
2.30.1