From 428f4169ab241c0a67171505549f16d790043f5d Mon Sep 17 00:00:00 2001
From: Ziad Elhanafy <ziad.elhanafy@arm.com>
Date: Mon, 15 Jul 2024 09:18:45 +0100
Subject: [PATCH] docs(rd1ae): update documentation to include BL32
Update the boot sequence in the RD-1 AE documentation
to include BL32 (OP-TEE).
Signed-off-by: Ziad Elhanafy <ziad.elhanafy@arm.com>
Change-Id: I25fdc114bb71d3ad7e1bb2d845f758d6af037e3d
---
docs/plat/arm/automotive_rd/index.rst | 36 +++++++++++++++++++++------
1 file changed, 29 insertions(+), 7 deletions(-)
diff --git a/docs/plat/arm/automotive_rd/index.rst b/docs/plat/arm/automotive_rd/index.rst
index d0db6ac56..04ca2b91e 100644
--- a/docs/plat/arm/automotive_rd/index.rst
+++ b/docs/plat/arm/automotive_rd/index.rst
@@ -11,15 +11,34 @@ Further information on RD1-AE is available at `rd1ae`_
Boot Sequence
-------------
-BL2 –> BL31 –> BL33
+The boot process starts from RSE (Runtime Security Engine) that loads the
+Application Processor (AP) BL2 image and signals the System Control Processor (SCP)
+to power up the AP. The AP then runs AP BL2
-The boot process starts from RSE (Runtime Security Engine) that loads the BL2 image
-and signals the System Control Processor (SCP) to power up the Application Processor (AP).
-The AP then runs BL2, which loads the rest of the images, including the runtime firmware
-BL31, and proceeds to execute it. Finally, it passes control to the non-secure world
-BL33 (u-boot).
+The primary compute boot flow follows the following steps:
-BL2 performs the actions described in the `Trusted Board Boot (TBB)`_ document.
+1. AP BL2:
+
+ * Performs the actions described in the `Trusted Board Boot (TBB)`_ document.
+ * Copies the AP BL31 image from Secure Flash to Secure SRAM
+ * Copies the AP BL32 (OP-TEE) image from Secure Flash to Secure DRAM
+ * Copies the AP BL33 (U-Boot) image from Secure Flash to Normal DRAM
+ * Transfers the execution to AP BL31
+
+2. AP BL31:
+
+ * Initializes Trusted Firmware-A Services
+ * Transfers the execution to AP BL32 and then transfers the execution to AP BL33
+ * During runtime, acts as the Secure Monitor, handling SMC calls,
+ and context switching between secure and non-secure worlds.
+
+3. AP BL32:
+
+ * Initializes OP-TEE environment
+ * Initializes Secure Partitions
+ * Transfers the execution back to AP BL31
+ * During runtime, it facilitates secure communication between the
+ normal world environment (e.g. Linux) and the Trusted Execution Environment.
Build Procedure (TF-A only)
~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -41,6 +60,9 @@ Build Procedure (TF-A only)
COT=tbbr \
ARM_ROTPK_LOCATION=devel_rsa \
ROT_KEY=plat/arm/board/common/rotpk/arm_rotprivk_rsa.pem \
+ BL32=<path to optee binary> \
+ SPD=spmd \
+ SPMD_SPM_AT_SEL2=0 \
BL33=<path to u-boot binary> \
*Copyright (c) 2024, Arm Limited. All rights reserved.*