From 2c573ff69d50a9676e8c730bb733ceb2c9aa5157 Mon Sep 17 00:00:00 2001 From: Bastian Krause Date: Fri, 25 Feb 2022 11:03:44 +0100 Subject: arch: arm: mach-imx: document field return in CSF template Activating the field return configuration returns a locked-down board (nearly) to its open state. In order to burn the FIELD_RETURN fuse, the CSF must contain a specific unlock command with the device's UID. Signed-off-by: Bastian Krause Link: https://lore.barebox.org/20220225100344.4166248-1-bst@pengutronix.de Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/include/mach/habv4-imx6-gencsf-template.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/arm/mach-imx') diff --git a/arch/arm/mach-imx/include/mach/habv4-imx6-gencsf-template.h b/arch/arm/mach-imx/include/mach/habv4-imx6-gencsf-template.h index a60b485292..45da2981cb 100644 --- a/arch/arm/mach-imx/include/mach/habv4-imx6-gencsf-template.h +++ b/arch/arm/mach-imx/include/mach/habv4-imx6-gencsf-template.h @@ -39,6 +39,18 @@ hab Engine = SETUP_HABV4_ENGINE hab Features = SETUP_HABV4_FEATURES #endif +/* +// allow fusing FIELD_RETURN +// # ocotp0.permanent_write_enable=1 +// # mw -l -d /dev/imx-ocotp 0xb8 0x1 +hab [Unlock] +hab Engine = OCOTP +hab Features = FIELD RETURN +// device-specific UID: +// $ dd if=/sys/bus/nvmem/devices/imx-ocotp0/nvmem bs=4 skip=1 count=2 status=none | hexdump -ve '1/1 "0x%.2x, "' | sed 's/, $//' +hab UID = 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 +*/ + hab [Install Key] /* verification key index in key store (0, 2...4) */ hab Verification index = 0 -- cgit v1.2.3