STM32C0 support

Author: billphipps

arch.mk

@@ -83,6 +83,17 @@ ifeq ($(ARCH),ARM)
     CORTEX_M0=1
     SPI_TARGET=stm32
   endif
+
+  ifeq ($(TARGET),stm32c0)
+    CORTEX_M0=1
+    ARCH_FLASH_OFFSET=0x08000000
+
+    # Enable this feature for secure memory support
+    # Makes the flash sectors for the bootloader unacessible from the application
+    # Requires using the STM32CubeProgrammer to set FLASH_SECR -> SEC_SIZE pages
+    CFLAGS+=-DFLASH_SECURABLE_MEMORY_SUPPORT
+  endif
+
   ifeq ($(TARGET),stm32g0)
     CORTEX_M0=1
     ARCH_FLASH_OFFSET=0x08000000

config/examples/stm32c0.config

@@ -0,0 +1,34 @@
+ARCH?=ARM
+TARGET?=stm32c0
+SIGN?=ED25519
+#Using SHA384 with ED25519 saves about 2kB without SHA256 code
+HASH?=SHA384
+DEBUG?=0
+VTOR?=1
+CORTEX_M0?=1
+NO_ASM?=0
+EXT_FLASH?=0
+SPI_FLASH?=0
+ALLOW_DOWNGRADE?=0
+NVM_FLASH_WRITEONCE?=1
+WOLFBOOT_VERSION?=0
+V?=0
+SPMATH?=1
+RAM_CODE?=1
+DUALBANK_SWAP?=0
+#Max APP size is 4kB
+WOLFBOOT_PARTITION_SIZE?=0x2000
+WOLFBOOT_SECTOR_SIZE?=0x800
+#Max WOLFBOOT size is 14kB. Currently only 10kB
+WOLFBOOT_PARTITION_BOOT_ADDRESS?=0x08003800
+WOLFBOOT_PARTITION_UPDATE_ADDRESS?=0x08005800
+WOLFBOOT_PARTITION_SWAP_ADDRESS?=0x08007800
+
+#For a debug/not size optimized layout:
+#DEBUG?=1
+#WOLFBOOT_PARTITION_SIZE?=0x1000
+#WOLFBOOT_SECTOR_SIZE?=0x800
+#WOLFBOOT_PARTITION_BOOT_ADDRESS?=0x08005800
+#WOLFBOOT_PARTITION_UPDATE_ADDRESS?=0x08006800
+#WOLFBOOT_PARTITION_SWAP_ADDRESS?=0x08007800
+

docs/HAL.md

@@ -19,7 +19,7 @@ and RAM boundaries.
 ## Supported platforms
 
 The following platforms are supported in the current version:
-  - STM32F4, STM32L5, STM32L0, STM32F7, STM32H7, STM32G0
+  - STM32F4, STM32L5, STM32L0, STM32F7, STM32H7, STM32G0, STM32C0
   - nRF52
   - Atmel samR21
   - TI cc26x2

docs/Targets.md

@@ -21,6 +21,7 @@ This README describes configuration of supported targets.
 * [STM32L4](#stm32l4)
 * [STM32L5](#stm32l5)
 * [STM32G0](#stm32g0)
+* [STM32C0](#stm32c0)
 * [STM32H7](#stm32h7)
 * [STM32U5](#stm32u5)
 * [STM32WB55](#stm32wb55)
@@ -424,6 +425,82 @@ add-symbol-file test-app/image.elf 0x08008100
 mon reset init
 ```
 
+## STM32C0
+
+Supports STM32C0x0/STM32C0x1.
+
+Example and instructions are for the STM Nucleo-C031C6 dev board using the 
+STM32Cube 
+
+Example 32KB partitioning on STM32-G070:
+
+- Sector size: 2KB
+- Wolfboot partition size: 14KB
+- Application partition size: 8 KB
+- Swap size 2KB
+
+```C
+#define WOLFBOOT_SECTOR_SIZE                 0x800   /* 2 KB */
+#define WOLFBOOT_PARTITION_BOOT_ADDRESS      0x08004000 /* offset 16kB to 24kB */
+#define WOLFBOOT_PARTITION_SIZE              0x2000  /* 8 KB */
+#define WOLFBOOT_PARTITION_UPDATE_ADDRESS    0x08006000 /* offset 24kB to 32kB */
+#define WOLFBOOT_PARTITION_SWAP_ADDRESS      0x08003800 /* offset 14kB to 16kB */
+```
+
+### Building STM32C0
+xxx
+Reference configuration (see [/config/examples/stm32g0.config](/config/examples/stm32g0.config)).
+You can copy this to wolfBoot root as `.config`: `cp ./config/examples/stm32g0.config .config`.
+To build you can use `make`.
+
+The TARGET for this is `stm32g0`: `make TARGET=stm32g0`.
+The option `CORTEX_M0` is automatically selected for this target.
+The option `NVM_FLASH_WRITEONCE=1` is mandatory on this target, since the IAP driver does not support
+multiple writes after each erase operation.
+
+This target also supports secure memory protection on the bootloader region
+using the `FLASH_CR:SEC_PROT` and `FLASH_SECT:SEC_SIZE` registers. This is the
+number of 2KB pages to block access to from the 0x8000000 base address.
+
+```
+STM32_Programmer_CLI -c port=swd mode=hotplug -ob SEC_SIZE=0x10
+```
+
+For RAMFUNCTION support (required for SEC_PROT) make sure `RAM_CODE=1`.
+
+### STM32C0 Programming
+xxx
+Compile requirements: `make TARGET=stm32g0 NVM_FLASH_WRITEONCE=1`
+
+The output is a single `factory.bin` that includes `wolfboot.bin` and `test-app/image_v1_signed.bin` combined together.
+This should be programmed to the flash start address `0x08000000`.
+
+Flash using the STM32CubeProgrammer CLI:
+
+```
+STM32_Programmer_CLI -c port=swd -d factory.bin 0x08000000
+```
+
+### STM32C0 Debugging
+xxx
+Use `make DEBUG=1` and program firmware again.
+
+Start GDB server on port 3333:
+
+```
+ST-LINK_gdbserver -d -e -r 1 -p 3333
+OR
+st-util -p 3333
+```
+
+wolfBoot has a .gdbinit to configure GDB
+
+```
+arm-none-eabi-gdb
+add-symbol-file test-app/image.elf 0x08008100
+mon reset init
+```
+
 
 ## STM32WB55