summaryrefslogtreecommitdiffstats
path: root/Documentation/boards
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/boards')
-rw-r--r--Documentation/boards/imx/nxp-imx8mm-evk.rst18
-rw-r--r--Documentation/boards/imx/nxp-imx8mn-evk.rst24
-rw-r--r--Documentation/boards/imx/nxp-imx8mp-evk.rst24
3 files changed, 66 insertions, 0 deletions
diff --git a/Documentation/boards/imx/nxp-imx8mm-evk.rst b/Documentation/boards/imx/nxp-imx8mm-evk.rst
index c3cd35ae38..f0dfc53ed0 100644
--- a/Documentation/boards/imx/nxp-imx8mm-evk.rst
+++ b/Documentation/boards/imx/nxp-imx8mm-evk.rst
@@ -69,3 +69,21 @@ board for serial download mode as printed on the PCB. You can start barebox with
the imx-usb-loader tool that comes with barebox like this:
./scripts/imx/imx-usb-loader images/barebox-nxp-imx8mm-evk.img
+
+Installing barebox
+==================
+
+When the EVK is strapped to boot from eMMC, the i.MX8M bootrom will
+consult the eMMC ext_csd register to determine whether to boot
+from the active eMMC boot partition or from the user area.
+
+The same barebox image written to the start of the SD-Card can
+be written to the start of the eMMC user area. Power-fail-safe
+installation to the eMMC boot partition requires special handling:
+
+ - The barebox image must be written to the inactive boot partition,
+ then afterwards, the newly written boot partition is activated
+ (This is controlled by the barebox ``mmcX.boot`` variable).
+
+The ``barebox_update`` command takes care of this and need just be
+supplied a barebox image as argument.
diff --git a/Documentation/boards/imx/nxp-imx8mn-evk.rst b/Documentation/boards/imx/nxp-imx8mn-evk.rst
index b920e22d33..177fc59c10 100644
--- a/Documentation/boards/imx/nxp-imx8mn-evk.rst
+++ b/Documentation/boards/imx/nxp-imx8mn-evk.rst
@@ -58,3 +58,27 @@ Build barebox
make imx_v8_defconfig
make
+
+Installing barebox
+==================
+
+When the EVK is strapped to boot from eMMC, the i.MX8M bootrom will
+consult the eMMC ext_csd register to determine whether to boot
+from the active eMMC boot partition or from the user area.
+
+The same barebox image written to the start of the SD-Card can
+be written to the start of the eMMC user area. Power-fail-safe
+installation to the eMMC boot partition requires special handling:
+
+ - The barebox image must be written to the inactive boot partition,
+ then afterwards, the newly written boot partition is activated
+ (This is controlled by the barebox ``mmcX.boot`` variable).
+
+ - The barebox image includes a 32KiB preamble that allows the image
+ to be directly writable to the start of the SD-Card or eMMC user area.
+ Unlike older i.MX8M, the i.MX8MN BootROM expects the bootloader to not
+ start at an offset when booting from eMMC boot partitions, thus the first
+ 32KiB must be stripped.
+
+The ``barebox_update`` command takes care of this and need just be
+supplied a barebox image as argument.
diff --git a/Documentation/boards/imx/nxp-imx8mp-evk.rst b/Documentation/boards/imx/nxp-imx8mp-evk.rst
index 1074992f2f..53cdd904ab 100644
--- a/Documentation/boards/imx/nxp-imx8mp-evk.rst
+++ b/Documentation/boards/imx/nxp-imx8mp-evk.rst
@@ -66,3 +66,27 @@ Boot Configuration
The NXP i.MX8MP-EVK board has four switches responsible for configuring
bootsource/boot mode. The settings for the different boot sources are
printed on the board.
+
+Installing barebox
+==================
+
+When the EVK is strapped to boot from eMMC, the i.MX8M bootrom will
+consult the eMMC ext_csd register to determine whether to boot
+from the active eMMC boot partition or from the user area.
+
+The same barebox image written to the start of the SD-Card can
+be written to the start of the eMMC user area. Power-fail-safe
+installation to the eMMC boot partition requires special handling:
+
+ - The barebox image must be written to the inactive boot partition,
+ then afterwards, the newly written boot partition is activated
+ (This is controlled by the barebox ``mmcX.boot`` variable).
+
+ - The barebox image includes a 32KiB preamble that allows the image
+ to be directly writable to the start of the SD-Card or eMMC user area.
+ Unlike older i.MX8M, the i.MX8MP BootROM expects the bootloader to not
+ start at an offset when booting from eMMC boot partitions, thus the first
+ 32KiB must be stripped.
+
+The ``barebox_update`` command takes care of this and need just be
+supplied a barebox image as argument.