From 156a61d16e3661739749b90bdf5a243f8a26c8dc Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Fri, 28 Aug 2020 19:31:15 +0200 Subject: Documentation: boards: stm32mp: document eMMC boot configuration In order to boot from eMMC on the STM32MP15x, the boot_ack bit in the ext_csd register must be set. Document this and while at it, fix a misformatted code block in the same section. Signed-off-by: Ahmad Fatoum Signed-off-by: Bastian Krause Signed-off-by: Sascha Hauer --- Documentation/boards/stm32mp.rst | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'Documentation/boards') diff --git a/Documentation/boards/stm32mp.rst b/Documentation/boards/stm32mp.rst index 7c657eb990..b235c39927 100644 --- a/Documentation/boards/stm32mp.rst +++ b/Documentation/boards/stm32mp.rst @@ -64,7 +64,7 @@ An appropriate image for a SD-Card can be generated with following } For eMMC, the boot partitions are used as the FSBL partitions and so the user -partitions may look like this: +partitions may look like this:: image @STM32MP_BOARD@.img { partition ssbl { @@ -80,6 +80,17 @@ partitions may look like this: The fsbl1 and fsbl2 can be flashed by writing to barebox ``/dev/mmcX.boot0`` and ``/dev/mmcX.boot1`` respectively or from a booted operating system. +Additionally, the eMMC's ``ext_csd`` register must be modified to activate the +boot acknowledge signal (``BOOT_ACK``) and to select a boot partition. + +Assuming ``CONFIG_CMD_MMC_EXTCSD`` is enabled and the board shall boot from +``/dev/mmc1.boot1``:: + + mmc_extcsd /dev/mmc1 -i 179 -v 0x50 + +The STM32MP1 BootROM does *not* support booting from eMMC without fast boot +acknowledge. + Boot source selection --------------------- -- cgit v1.2.3