Introduce PROGRAMMABLE_RESET_ADDRESS build option

This patch introduces a new platform build option, called
PROGRAMMABLE_RESET_ADDRESS, which tells whether the platform has
a programmable or fixed reset vector address.

If the reset vector address is fixed then the code relies on the
platform_get_entrypoint() mailbox mechanism to figure out where
it is supposed to jump. On the other hand, if it is programmable
then it is assumed that the platform code will program directly
the right address into the RVBAR register (instead of using the
mailbox redirection) so the mailbox is ignored in this case.

Change-Id: If59c3b11fb1f692976e1d8b96c7e2da0ebfba308

diff --git a/Makefile b/Makefile
index d38a28327af21b5fe708e6fbe2836bd8c4803db1..9fabdcad603bff769a84d6453ba2f7f92327ba91 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -76,6 +76,9 @@ CREATE_KEYS           := 1
 # Flags to build TF with Trusted Boot support
 TRUSTED_BOARD_BOOT     := 0
 AUTH_MOD               := none
+# By default, consider that the platform's reset address is not programmable.
+# The platform Makefile is free to override this value.
+PROGRAMMABLE_RESET_ADDRESS     := 0
 
 # Checkpatch ignores
 CHECK_IGNORE           =       --ignore COMPLEX_MACRO \
@@ -271,6 +274,10 @@ $(eval $(call assert_boolean,CREATE_KEYS))
 $(eval $(call assert_boolean,TRUSTED_BOARD_BOOT))
 $(eval $(call add_define,TRUSTED_BOARD_BOOT))
 
+# Process PROGRAMMABLE_RESET_ADDRESS flag
+$(eval $(call assert_boolean,PROGRAMMABLE_RESET_ADDRESS))
+$(eval $(call add_define,PROGRAMMABLE_RESET_ADDRESS))
+
 ASFLAGS                        +=      -nostdinc -ffreestanding -Wa,--fatal-warnings   \
                                -Werror -Wmissing-include-dirs                  \
                                -mgeneral-regs-only -D__ASSEMBLY__              \

diff --git a/bl1/aarch64/bl1_entrypoint.S b/bl1/aarch64/bl1_entrypoint.S
index 147c930c37b029d769de0c7140ec4697ed84a3e0..4fc52918adf549c9f1f3b504b518f183d8b2ff88 100644 (file)
--- a/bl1/aarch64/bl1_entrypoint.S
+++ b/bl1/aarch64/bl1_entrypoint.S
@@ -42,9 +42,15 @@
         */
 
 func bl1_entrypoint
+       /* ---------------------------------------------------------------------
+        * If the reset address is programmable then bl1_entrypoint() is
+        * executed only on the cold boot path. Therefore, we can skip the warm
+        * boot mailbox mechanism.
+        * ---------------------------------------------------------------------
+        */
        el3_entrypoint_common                                   \
                _set_endian=1                                   \
-               _warm_boot_mailbox=1                            \
+               _warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS  \
                _secondary_cold_boot=1                          \
                _init_memory=1                                  \
                _init_c_runtime=1                               \

diff --git a/bl31/aarch64/bl31_entrypoint.S b/bl31/aarch64/bl31_entrypoint.S
index 5350f68fc42543643f8df7dcdbf12daa37fe2da7..5ba0f9cc4b60588196bf97edc3f7a407c55e56ab 100644 (file)
--- a/bl31/aarch64/bl31_entrypoint.S
+++ b/bl31/aarch64/bl31_entrypoint.S
@@ -76,9 +76,15 @@ func bl31_entrypoint
        mov     x0, x20
        mov     x1, x21
 #else
+       /* ---------------------------------------------------------------------
+        * For RESET_TO_BL31 systems which have a programmable reset address,
+        * bl31_entrypoint() is executed only on the cold boot path so we can
+        * skip the warm boot mailbox mechanism.
+        * ---------------------------------------------------------------------
+        */
        el3_entrypoint_common                                   \
                _set_endian=1                                   \
-               _warm_boot_mailbox=1                            \
+               _warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS  \
                _secondary_cold_boot=1                          \
                _init_memory=1                                  \
                _init_c_runtime=1                               \

diff --git a/docs/user-guide.md b/docs/user-guide.md
index c1cadbbe8cbd9a7f359e1d74811b9a45a34cbe4c..908665cbcf47d6b6eebec5eefcab5ca40ad6c13e 100644 (file)
--- a/docs/user-guide.md
+++ b/docs/user-guide.md
@@ -320,6 +320,10 @@ performed.
 *   `BL33_KEY`: This option is used when `GENERATE_COT=1`. It specifies the
     file that contains the BL3-3 private key in PEM format.
 
+*   `PROGRAMMABLE_RESET_ADDRESS`: This option indicates whether the reset
+    vector address can be programmed or is fixed on the platform. It can take
+    either 0 (fixed) or 1 (programmable). Default is 0.
+
 #### ARM development platform specific build options
 
 *   `ARM_TSP_RAM_LOCATION_ID`: location of the TSP binary. Options:

diff --git a/services/std_svc/psci/psci_entry.S b/services/std_svc/psci/psci_entry.S
index 3f221590574a86b0c2406f957b86778f8ee26a4f..050f6c6c6de2ab32734891b8504aac528db7b900 100644 (file)
--- a/services/std_svc/psci/psci_entry.S
+++ b/services/std_svc/psci/psci_entry.S
@@ -57,6 +57,11 @@ psci_aff_common_finish_entry:
         * On the warm boot path, most of the EL3 initialisations performed by
         * 'el3_entrypoint_common' must be skipped:
         *
+        *  - Only when the platform bypasses the BL1/BL3-1 entrypoint by
+        *    programming the reset address do we need to set the CPU endianness.
+        *    In other cases, we assume this has been taken care by the
+        *    entrypoint code.
+        *
         *  - No need to determine the type of boot, we know it is a warm boot.
         *
         *  - Do not try to distinguish between primary and secondary CPUs, this
@@ -66,7 +71,7 @@ psci_aff_common_finish_entry:
         *    it has been done once and for all on the cold boot path.
         */
        el3_entrypoint_common                                   \
-               _set_endian=0                                   \
+               _set_endian=PROGRAMMABLE_RESET_ADDRESS          \
                _warm_boot_mailbox=0                            \
                _secondary_cold_boot=0                          \
                _init_memory=0                                  \