docs: Firmware design update for BL memory layout
This patch updates the firmware design guide for the BL memory
layout change on ARM platforms.
Change-Id: Icbfe7249484bb8b4ba3c94421172d42f27605c52
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/docs/firmware-design.rst b/docs/firmware-design.rst
index 477eeaa..51f5b42 100644
--- a/docs/firmware-design.rst
+++ b/docs/firmware-design.rst
@@ -516,8 +516,8 @@
in memory and changing the address where the system jumps at reset.
For example:
- -C cluster0.cpu0.RVBAR=0x4014000
- --data cluster0.cpu0=bl2.bin@0x4014000
+ -C cluster0.cpu0.RVBAR=0x4020000
+ --data cluster0.cpu0=bl2.bin@0x4020000
With this configuration, FVP is like a platform of the first case,
where the Boot ROM jumps always to the same address. For simplification,
@@ -1743,17 +1743,20 @@
this is also used for the MHU payload when passing messages to and from the
SCP.
+- Another 4 KB page is reserved for passing memory layout between BL1 and BL2
+ and also the dynamic firmware configurations.
+
- On FVP, BL1 is originally sitting in the Trusted ROM at address ``0x0``. On
Juno, BL1 resides in flash memory at address ``0x0BEC0000``. BL1 read-write
data are relocated to the top of Trusted SRAM at runtime.
+- BL2 is loaded below BL1 RW
+
- EL3 Runtime Software, BL31 for AArch64 and BL32 for AArch32 (e.g. SP\_MIN),
is loaded at the top of the Trusted SRAM, such that its NOBITS sections will
- overwrite BL1 R/W data. This implies that BL1 global variables remain valid
- only until execution reaches the EL3 Runtime Software entry point during a
- cold boot.
-
-- BL2 is loaded below EL3 Runtime Software.
+ overwrite BL1 R/W data and BL2. This implies that BL1 global variables
+ remain valid only until execution reaches the EL3 Runtime Software entry
+ point during a cold boot.
- On Juno, SCP\_BL2 is loaded temporarily into the EL3 Runtime Software memory
region and transfered to the SCP before being overwritten by EL3 Runtime
@@ -1766,9 +1769,8 @@
- Secure region of DRAM (top 16MB of DRAM configured by the TrustZone
controller)
- When BL32 (for AArch64) is loaded into Trusted SRAM, its NOBITS sections
- are allowed to overlay BL2. This memory layout is designed to give the
- BL32 image as much memory as possible when it is loaded into Trusted SRAM.
+ When BL32 (for AArch64) is loaded into Trusted SRAM, it is loaded below
+ BL31.
When LOAD\_IMAGE\_V2 is disabled the memory regions for the overlap detection
mechanism at boot time are defined as follows (shown per API):
@@ -1814,21 +1816,32 @@
Note: Loading the BL32 image in TZC secured DRAM doesn't change the memory
layout of the other images in Trusted SRAM.
-**FVP with TSP in Trusted SRAM (default option):**
+**FVP with TSP in Trusted SRAM with firmware configs :**
(These diagrams only cover the AArch64 case)
::
+ DRAM
+ 0xffffffff +----------+
+ : :
+ |----------|
+ |HW_CONFIG |
+ 0x83000000 |----------| (non-secure)
+ | |
+ 0x80000000 +----------+
+
Trusted SRAM
- 0x04040000 +----------+ loaded by BL2 ------------------
- | BL1 (rw) | <<<<<<<<<<<<< | BL31 NOBITS |
+ 0x04040000 +----------+ loaded by BL2 +----------------+
+ | BL1 (rw) | <<<<<<<<<<<<< | |
+ |----------| <<<<<<<<<<<<< | BL31 NOBITS |
+ | BL2 | <<<<<<<<<<<<< | |
|----------| <<<<<<<<<<<<< |----------------|
| | <<<<<<<<<<<<< | BL31 PROGBITS |
- |----------| ------------------
- | BL2 | <<<<<<<<<<<<< | BL32 NOBITS |
- |----------| <<<<<<<<<<<<< |----------------|
- | | <<<<<<<<<<<<< | BL32 PROGBITS |
- 0x04001000 +----------+ ------------------
+ | | <<<<<<<<<<<<< |----------------|
+ | | <<<<<<<<<<<<< | BL32 |
+ 0x04002000 +----------+ +----------------+
+ |fw_configs|
+ 0x04001000 +----------+
| Shared |
0x04000000 +----------+
@@ -1837,7 +1850,7 @@
| BL1 (ro) |
0x00000000 +----------+
-**FVP with TSP in Trusted DRAM with TB_FW_CONFIG and HW_CONFIG :**
+**FVP with TSP in Trusted DRAM with firmware configs (default option):**
::
@@ -1856,17 +1869,15 @@
0x06000000 +--------------+
Trusted SRAM
- 0x04040000 +--------------+ loaded by BL2 ------------------
- | BL1 (rw) | <<<<<<<<<<<<< | BL31 NOBITS |
+ 0x04040000 +--------------+ loaded by BL2 +----------------+
+ | BL1 (rw) | <<<<<<<<<<<<< | |
+ |--------------| <<<<<<<<<<<<< | BL31 NOBITS |
+ | BL2 | <<<<<<<<<<<<< | |
|--------------| <<<<<<<<<<<<< |----------------|
| | <<<<<<<<<<<<< | BL31 PROGBITS |
- |--------------| ------------------
- | BL2 |
- |--------------|
- | |
- |--------------|
- | TB_FW_CONFIG |
- |--------------|
+ | | +----------------+
+ +--------------+
+ | fw_configs |
0x04001000 +--------------+
| Shared |
0x04000000 +--------------+
@@ -1876,7 +1887,7 @@
| BL1 (ro) |
0x00000000 +--------------+
-**FVP with TSP in TZC-Secured DRAM:**
+**FVP with TSP in TZC-Secured DRAM with firmware configs :**
::
@@ -1885,19 +1896,22 @@
| BL32 | (secure)
0xff000000 +----------+
| |
- : : (non-secure)
+ |----------|
+ |HW_CONFIG |
+ 0x83000000 |----------| (non-secure)
| |
0x80000000 +----------+
Trusted SRAM
- 0x04040000 +----------+ loaded by BL2 ------------------
- | BL1 (rw) | <<<<<<<<<<<<< | BL31 NOBITS |
+ 0x04040000 +----------+ loaded by BL2 +----------------+
+ | BL1 (rw) | <<<<<<<<<<<<< | |
+ |----------| <<<<<<<<<<<<< | BL31 NOBITS |
+ | BL2 | <<<<<<<<<<<<< | |
|----------| <<<<<<<<<<<<< |----------------|
| | <<<<<<<<<<<<< | BL31 PROGBITS |
- |----------| ------------------
- | BL2 |
- |----------|
- | |
+ | | +----------------+
+ 0x04002000 +----------+
+ |fw_configs|
0x04001000 +----------+
| Shared |
0x04000000 +----------+
@@ -1907,7 +1921,7 @@
| BL1 (ro) |
0x00000000 +----------+
-**Juno with BL32 in Trusted SRAM (default option):**
+**Juno with BL32 in Trusted SRAM :**
::
@@ -1921,19 +1935,21 @@
0x08000000 +----------+ BL31 is loaded
after SCP_BL2 has
Trusted SRAM been sent to SCP
- 0x04040000 +----------+ loaded by BL2 ------------------
- | BL1 (rw) | <<<<<<<<<<<<< | BL31 NOBITS |
+ 0x04040000 +----------+ loaded by BL2 +----------------+
+ | BL1 (rw) | <<<<<<<<<<<<< | |
+ |----------| <<<<<<<<<<<<< | BL31 NOBITS |
+ | BL2 | <<<<<<<<<<<<< | |
|----------| <<<<<<<<<<<<< |----------------|
| SCP_BL2 | <<<<<<<<<<<<< | BL31 PROGBITS |
- |----------| ------------------
- | BL2 | <<<<<<<<<<<<< | BL32 NOBITS |
|----------| <<<<<<<<<<<<< |----------------|
- | | <<<<<<<<<<<<< | BL32 PROGBITS |
- 0x04001000 +----------+ ------------------
+ | | <<<<<<<<<<<<< | BL32 |
+ | | +----------------+
+ | |
+ 0x04001000 +----------+
| MHU |
0x04000000 +----------+
-**Juno with BL32 in TZC-secured DRAM:**
+**Juno with BL32 in TZC-secured DRAM :**
::
@@ -1956,14 +1972,13 @@
0x08000000 +----------+ BL31 is loaded
after SCP_BL2 has
Trusted SRAM been sent to SCP
- 0x04040000 +----------+ loaded by BL2 ------------------
- | BL1 (rw) | <<<<<<<<<<<<< | BL31 NOBITS |
+ 0x04040000 +----------+ loaded by BL2 +----------------+
+ | BL1 (rw) | <<<<<<<<<<<<< | |
+ |----------| <<<<<<<<<<<<< | BL31 NOBITS |
+ | BL2 | <<<<<<<<<<<<< | |
|----------| <<<<<<<<<<<<< |----------------|
| SCP_BL2 | <<<<<<<<<<<<< | BL31 PROGBITS |
- |----------| ------------------
- | BL2 |
- |----------|
- | |
+ |----------| +----------------+
0x04001000 +----------+
| MHU |
0x04000000 +----------+