Update stm32l562e-dk:nsh

- Update TrustedFirmare-M instructions to latest version of STM32CubeL5
- Increase idle thread stack size to not overflow during system init
- Select ARCH_HAVE_TRUSTZONE for STM32L5
- Set CONFIG_ARCH_TRUSTZONE_NONSECURE for stm32l562e-dk:nsh, since NuttX
  is running in the Non-secure world.

See https://github.com/apache/nuttx/issues/9316

Signed-off-by: Michael Jung <michael.jung@secore.ly>

arch/arm/Kconfig

@@ -489,6 +489,7 @@ config ARCH_CHIP_STM32L5
 	select ARCH_HAVE_PROGMEM
 	select ARCH_HAVE_SPI_BITORDER
 	select ARCH_HAVE_TICKLESS
+	select ARCH_HAVE_TRUSTZONE
 	select ARM_HAVE_MPU_UNIFIED
 	select ARMV8M_HAVE_STACKCHECK
 	---help---

boards/arm/stm32l5/stm32l562e-dk/README.txt

@@ -107,15 +107,15 @@ TrustedFirmware-M
 =================
 
   You should study [UM2671] STMicroelectronics. UM2671: Getting started with
-  STM32CubeL5 TFM application, 2nd edition, July 2020.
+  STM32CubeL5 TFM application, 3rd edition, June 2021.
 
-  I was using STM32CubeL5 v1.3.1
-  (https://github.com/STMicroelectronics/STM32CubeL5/tree/v1.3.1).
+  I was using STM32CubeL5 v1.5.0
+  (https://github.com/STMicroelectronics/STM32CubeL5/tree/v1.5.0).
 
   Changes required to STM32CubeL5's TFM
   -------------------------------------
 
-  The following two changes to TFM have to be applied to be able to run NuttX.
+  The following three changes to TFM have to be applied to be able to run NuttX.
 
   The first one is required since NuttX issues SVC instructions while interrupts
   are disabled, which causes HardFaults.  NuttX then detects this situation in
@@ -146,6 +146,22 @@ TrustedFirmware-M
      return TFM_PLAT_ERR_SUCCESS;
    }
 
+  The third chage is required, since current NuttX does not support lazy FPU
+  register stacking any longer.  Thus, this must be disabled for the TF-M secure
+  code as well:
+
+  --- a/Projects/STM32L562E-DK/Applications/TFM/TFM_Appli/Secure/Src/target_cfg.c
+  +++ b/Projects/STM32L562E-DK/Applications/TFM/TFM_Appli/Secure/Src/target_cfg.c
+  @@ -134,7 +134,7 @@ void sau_and_idau_cfg(void)
+     SCB->NSACR = (SCB->NSACR & ~(SCB_NSACR_CP10_Msk | SCB_NSACR_CP11_Msk)) |
+                  ((SCB_NSACR_CP10_11_VAL << SCB_NSACR_CP10_Pos) & (SCB_NSACR_CP10_Msk | SCB_NSACR_CP11_Msk));
+
+  -  FPU->FPCCR = (FPU->FPCCR & ~(FPU_FPCCR_TS_Msk | FPU_FPCCR_CLRONRETS_Msk | FPU_FPCCR_CLRONRET_Msk)) |
+  +  FPU->FPCCR = (FPU->FPCCR & ~(FPU_FPCCR_TS_Msk | FPU_FPCCR_CLRONRETS_Msk | FPU_FPCCR_CLRONRET_Msk | FPU_FPCCR_LSPEN_Msk)) |
+                  ((FPU_FPCCR_TS_VAL        << FPU_FPCCR_TS_Pos) & FPU_FPCCR_TS_Msk) |
+                  ((FPU_FPCCR_CLRONRETS_VAL << FPU_FPCCR_CLRONRETS_Pos) & FPU_FPCCR_CLRONRETS_Msk) |
+                  ((FPU_FPCCR_CLRONRET_VAL  << FPU_FPCCR_CLRONRET_Pos) & FPU_FPCCR_CLRONRET_Msk);
+
   Encrypting and Signing the NuttX Binary
   ---------------------------------------
 

boards/arm/stm32l5/stm32l562e-dk/configs/nsh/defconfig

@@ -18,6 +18,7 @@ CONFIG_ARCH_CHIP_STM32L5=y
 CONFIG_ARCH_INTERRUPTSTACK=2048
 CONFIG_ARCH_IRQBUTTONS=y
 CONFIG_ARCH_STACKDUMP=y
+CONFIG_ARCH_TRUSTZONE_NONSECURE=y
 CONFIG_ARMV8M_STACKCHECK=y
 CONFIG_BOARD_LOOPSPERMSEC=8499
 CONFIG_BUILTIN=y
@@ -31,6 +32,7 @@ CONFIG_FS_PROCFS=y
 CONFIG_FS_PROCFS_REGISTER=y
 CONFIG_HAVE_CXX=y
 CONFIG_HAVE_CXXINITIALIZE=y
+CONFIG_IDLETHREAD_STACKSIZE=2048
 CONFIG_INIT_ENTRYPOINT="nsh_main"
 CONFIG_NSH_ARCHINIT=y
 CONFIG_NSH_BUILTIN_APPS=y