commit 300c68da11fda3669d7b80b68dcd67b0b2082cbc
author Kevin Peng <kevin.peng@arm.com> Thu Aug 12 17:40:17 2021 +0800
committer Kevin Peng <kevin.peng@arm.com> Mon Sep 13 11:23:32 2021 +0800
tree a3e0cc35b8e7966b94631028d50f91c8c2f6a49e
parent e863e5ce570c9a76f633a765b22f1d608e24e75a

SPM: Use Main Stack for initialization

On reset, the Main Stack is used by default.
TF-M changes the stack to Processor Stack.

This patch remove the change to PSP in startup.s and:
- Rename the ARM_LIB_STACK to ER_INITIAL_PSP
- Rename the ARM_LIB_STACK_MSP to ARM_LIB_STACK
The renaming is to align the __main function of ARMClang where the
ARM_LIB_STACK is set to the current SP (MSP)

For Library Mode, the stacks are set to back to use PSP before entering
c code to avoid massive corresponding changes.

For FF-M implementations, this patch also:
- Seal the Main Stack before entering c code
- Manually free the Main Stack usage after initialization as the init
  function does not return

Change-Id: Ie1b6f2fca1f774c4812a89fa45bb039b16fe5af0
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
Co-authored-by: Summer Qin <summer.qin@arm.com>

secure_fw/spm/cmsis_func/spm_func.c

diff --git a/secure_fw/spm/cmsis_func/spm_func.c b/secure_fw/spm/cmsis_func/spm_func.c
index 882f517..5326f94 100644
--- a/secure_fw/spm/cmsis_func/spm_func.c
+++ b/secure_fw/spm/cmsis_func/spm_func.c
@@ -56,7 +56,7 @@
 static uint32_t *tfm_secure_stack_seal =
     ((uint32_t *)&REGION_NAME(Image$$, TFM_SECURE_STACK, $$ZI$$Limit)[-1]) - 2;
 
-REGION_DECLARE_T(Image$$, ARM_LIB_STACK_SEAL, $$ZI$$Base, uint32_t)[];
+REGION_DECLARE_T(Image$$, ER_INITIAL_PSP_SEAL, $$ZI$$Base, uint32_t)[];
 
 /*
  * Function to seal the psp stacks for Function model of TF-M.
@@ -84,11 +84,11 @@
     *(tfm_secure_stack_seal + 1) = TFM_STACK_SEAL_VALUE;
 
     /*
-     * Seal the ARM_LIB_STACK by writing the seal value to the reserved
+     * Seal the ER_INITIAL_PSP by writing the seal value to the reserved
      * region.
      */
     uint32_t *arm_lib_stck_seal_base =
-        ((uint32_t *)&REGION_NAME(Image$$, ARM_LIB_STACK_SEAL, $$ZI$$Base)[-1]) - 2;
+        ((uint32_t *)&REGION_NAME(Image$$, ER_INITIAL_PSP_SEAL, $$ZI$$Base)[-1]) - 2;
 
     *(arm_lib_stck_seal_base) = TFM_STACK_SEAL_VALUE;
     *(arm_lib_stck_seal_base + 1) = TFM_STACK_SEAL_VALUE;
@@ -652,9 +652,9 @@
             (struct tfm_state_context_t *)ret_part_data->stack_ptr);
         *excReturn = ret_part_data->lr;
         __set_PSP(ret_part_data->stack_ptr);
-        REGION_DECLARE_T(Image$$, ARM_LIB_STACK, $$ZI$$Base, uint32_t)[];
+        REGION_DECLARE_T(Image$$, ER_INITIAL_PSP, $$ZI$$Base, uint32_t)[];
         uint32_t psp_stack_bottom =
-            (uint32_t)REGION_NAME(Image$$, ARM_LIB_STACK, $$ZI$$Base);
+            (uint32_t)REGION_NAME(Image$$, ER_INITIAL_PSP, $$ZI$$Base);
         tfm_arch_set_psplim(psp_stack_bottom);
 
         iovec_args = &REGION_NAME(Image$$, TFM_SECURE_STACK, $$ZI$$Limit)[-1];