Juno: Add support for image overlaying in Trusted SRAM
This patch allows the BL3-1 NOBITS section to overlap the BL1 R/W
section since the former will always be used after the latter.
Similarly, the BL3-2 NOBITS section can overlay the BL2 image
when BL3-2 is loaded in Trusted SRAM.
Due to the current size of the images, there is no actual overlap.
Nevertheless, this reorganization may help to optimise the Trusted
SRAM usage when the images size grows.
Note that because BL3-1 NOBITS section is allowed to overlap the
BL1 R/W section, BL1 global variables will remain valid only until
execution reaches the BL3-1 entry point during a cold boot.
Documentation updated accordingly.
Fixes ARM-software/tf-issues#254
Change-Id: Id538f4d1c7f1f7858108280fd7b97e138572b879
diff --git a/docs/firmware-design.md b/docs/firmware-design.md
index bc075da..e40ca96 100644
--- a/docs/firmware-design.md
+++ b/docs/firmware-design.md
@@ -1270,9 +1270,40 @@
Loading the TSP image in Trusted DRAM doesn't change the memory layout of the
other boot loader images in Trusted SRAM.
+
#### Memory layout on Juno ARM development platform
+The following list describes the memory layout on Juno:
+
+* Trusted SRAM at 0x04000000 contains the MHU page, BL1 r/w section, BL2
+ image, BL3-1 image and, optionally, the BL3-2 image.
+
+* The MHU 4 KB page is used as communication channel between SCP and AP. It
+ also contains the entrypoint mailboxes for the AP. Mailboxes are stored in
+ the first 128 bytes of the MHU page.
+
+* BL1 resides in flash memory at address `0x0BEC0000`. Its read-write data
+ section is relocated to the top of the Trusted SRAM at runtime.
+
+* BL3-1 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
+ will remain valid only until execution reaches the BL3-1 entry point during
+ a cold boot.
+
+* BL2 is loaded below BL3-1.
+
+* BL3-0 is loaded temporarily into the BL3-1 memory region and transfered to
+ the SCP before being overwritten by BL3-1.
+
-**TSP in Trusted SRAM (default option):**
+* The BL3-2 image is optional and can be loaded into one of these two
+ locations: Trusted SRAM (right after the MHU page) or DRAM (14 MB starting
+ at 0xFF000000 and secured by the TrustZone controller). When loaded into
+ Trusted SRAM, its NOBITS sections are allowed to overlap BL2.
+
+Depending on the location of the BL3-2 image, it will result in different memory
+maps, illustrated by the following diagrams.
+
+**BL3-2 in Trusted SRAM (default option):**
Flash0
0x0C000000 +----------+
@@ -1281,30 +1312,30 @@
| BL1 (ro) |
0x0BEC0000 |----------|
: :
- | Bypass |
- 0x08000000 +----------+
-
- Trusted SRAM
- 0x04040000 +----------+
- | BL2 | BL3-1 is loaded
- 0x04033000 |----------| after BL3-0 has
- | BL3-2 | been sent to SCP
- 0x04023000 |----------| ------------------
- | BL3-0 | <<<<<<<<<<<<< | BL3-1 |
- 0x04009000 |----------| ------------------
- | BL1 (rw) |
- 0x04001000 |----------|
+ 0x08000000 +----------+ BL3-1 is loaded
+ after BL3-0 has
+ Trusted SRAM been sent to SCP
+ 0x04040000 +----------+ loaded by BL2 ------------------
+ | BL1 (rw) | <<<<<<<<<<<<< | BL3-1 NOBITS |
+ |----------| <<<<<<<<<<<<< |----------------|
+ | BL3-0 | <<<<<<<<<<<<< | BL3-1 PROGBITS |
+ |----------| ------------------
+ | BL2 | <<<<<<<<<<<<< | BL3-2 NOBITS |
+ |----------| <<<<<<<<<<<<< |----------------|
+ | | <<<<<<<<<<<<< | BL3-2 PROGBITS |
+ 0x04001000 +----------+ ------------------
| MHU |
0x04000000 +----------+
+
-**TSP in the secure region of DRAM:**
+**BL3-2 in the secure region of DRAM:**
DRAM
0xFFE00000 +----------+
- | BL3-2 |
+ | BL3-2 | (secure)
0xFF000000 |----------|
| |
- : :
+ : : (non-secure)
| |
0x80000000 +----------+
@@ -1315,29 +1346,23 @@
| BL1 (ro) |
0x0BEC0000 |----------|
: :
- | Bypass |
- 0x08000000 +----------+
-
- Trusted SRAM
- 0x04040000 +----------+
- | BL2 | BL3-1 is loaded
- 0x04033000 |----------| after BL3-0 has
- | | been sent to SCP
- 0x04023000 |----------| ------------------
- | BL3-0 | <<<<<<<<<<<<< | BL3-1 |
- 0x04009000 |----------| ------------------
- | BL1 (rw) |
- 0x04001000 |----------|
+ 0x08000000 +----------+ BL3-1 is loaded
+ after BL3-0 has
+ Trusted SRAM been sent to SCP
+ 0x04040000 +----------+ loaded by BL2 ------------------
+ | BL1 (rw) | <<<<<<<<<<<<< | BL3-1 NOBITS |
+ |----------| <<<<<<<<<<<<< |----------------|
+ | BL3-0 | <<<<<<<<<<<<< | BL3-1 PROGBITS |
+ |----------| ------------------
+ | BL2 |
+ |----------|
+ | |
+ 0x04001000 +----------+
| MHU |
0x04000000 +----------+
-The Message Handling Unit (MHU) page contains the entrypoint mailboxes and a
-shared memory area. This shared memory is used as a communication channel
-between the AP and the SCP.
-
-BL1 code starts at `0x0BEC0000`. The BL1 data section is copied to trusted SRAM
-at `0x04001000`, right after the MHU page. Entrypoint mailboxes are stored in
-the first 128 bytes of the MHU page.
+Loading the BL3-2 image in DRAM doesn't change the memory layout of the other
+images in Trusted SRAM.
9. Firmware Image Package (FIP)
diff --git a/plat/juno/include/platform_def.h b/plat/juno/include/platform_def.h
index e746d02..ee77b83 100644
--- a/plat/juno/include/platform_def.h
+++ b/plat/juno/include/platform_def.h
@@ -76,38 +76,29 @@
#define MAX_IO_HANDLES 4
/*******************************************************************************
- * Platform memory map related constants
- ******************************************************************************/
-#define FLASH_BASE 0x08000000
-#define FLASH_SIZE 0x04000000
-
-/* Bypass offset from start of NOR flash */
-#define BL1_ROM_BYPASS_OFFSET 0x03EC0000
-
-#ifndef TZROM_BASE
-/* Use the bypass address */
-#define TZROM_BASE FLASH_BASE + BL1_ROM_BYPASS_OFFSET
-#endif
-#define TZROM_SIZE 0x00010000
-
-#define TZRAM_BASE 0x04001000
-#define TZRAM_SIZE 0x0003F000
-
-/*******************************************************************************
* BL1 specific defines.
* BL1 RW data is relocated from ROM to RAM at runtime so we need 2 base
* addresses.
******************************************************************************/
#define BL1_RO_BASE TZROM_BASE
#define BL1_RO_LIMIT (TZROM_BASE + TZROM_SIZE)
-#define BL1_RW_BASE TZRAM_BASE
-#define BL1_RW_LIMIT BL31_BASE
+
+/*
+ * Put BL1 RW at the top of the Trusted SRAM. BL1_RW_BASE is calculated using
+ * the current BL1 RW debug size plus a little space for growth.
+ */
+#define BL1_RW_BASE (TZRAM_BASE + TZRAM_SIZE - 0x6000)
+#define BL1_RW_LIMIT (TZRAM_BASE + TZRAM_SIZE)
/*******************************************************************************
* BL2 specific defines.
******************************************************************************/
-#define BL2_BASE (TZRAM_BASE + TZRAM_SIZE - 0xd000)
-#define BL2_LIMIT (TZRAM_BASE + TZRAM_SIZE)
+/*
+ * Put BL2 just below BL3-1. BL2_BASE is calculated using the current BL2 debug
+ * size plus a little space for growth.
+ */
+#define BL2_BASE (BL31_BASE - 0xC000)
+#define BL2_LIMIT BL31_BASE
/*******************************************************************************
* Load address of BL3-0 in the Juno port
@@ -119,8 +110,13 @@
/*******************************************************************************
* BL3-1 specific defines.
******************************************************************************/
-#define BL31_BASE (TZRAM_BASE + 0x8000)
-#define BL31_LIMIT BL32_BASE
+/*
+ * Put BL3-1 at the top of the Trusted SRAM. BL31_BASE is calculated using the
+ * current BL3-1 debug size plus a little space for growth.
+ */
+#define BL31_BASE (TZRAM_BASE + TZRAM_SIZE - 0x1D000)
+#define BL31_PROGBITS_LIMIT BL1_RW_BASE
+#define BL31_LIMIT (TZRAM_BASE + TZRAM_SIZE)
/*******************************************************************************
* BL3-2 specific defines.
@@ -128,8 +124,9 @@
#if (PLAT_TSP_LOCATION_ID == PLAT_TRUSTED_SRAM_ID)
# define TSP_SEC_MEM_BASE TZRAM_BASE
# define TSP_SEC_MEM_SIZE TZRAM_SIZE
-# define BL32_BASE (TZRAM_BASE + TZRAM_SIZE - 0x1d000)
-# define BL32_LIMIT BL2_BASE
+# define BL32_BASE TZRAM_BASE
+# define BL32_LIMIT BL31_BASE
+# define BL32_PROGBITS_LIMIT BL2_BASE
#elif (PLAT_TSP_LOCATION_ID == PLAT_DRAM_ID)
# define TSP_SEC_MEM_BASE DRAM_SEC_BASE
# define TSP_SEC_MEM_SIZE (DRAM_SEC_SIZE - DRAM_SCP_SIZE)
diff --git a/plat/juno/juno_def.h b/plat/juno/juno_def.h
index 88e35b0..cfcbe0b 100644
--- a/plat/juno/juno_def.h
+++ b/plat/juno/juno_def.h
@@ -37,6 +37,21 @@
/*******************************************************************************
* Juno memory map related constants
******************************************************************************/
+#define FLASH_BASE 0x08000000
+#define FLASH_SIZE 0x04000000
+
+/* Bypass offset from start of NOR flash */
+#define BL1_ROM_BYPASS_OFFSET 0x03EC0000
+
+#ifndef TZROM_BASE
+/* Use the bypass address */
+#define TZROM_BASE FLASH_BASE + BL1_ROM_BYPASS_OFFSET
+#endif
+#define TZROM_SIZE 0x00010000
+
+#define TZRAM_BASE 0x04001000
+#define TZRAM_SIZE 0x0003F000
+
#define PLAT_TRUSTED_SRAM_ID 0
#define PLAT_DRAM_ID 1