AT32F43x: make sure the SRAM configuration is valid (#13031)

src/link/at32_flash_f43xg.ld

@@ -23,13 +23,15 @@
     MEM   : 0x2000 0000 -- 0x2007 FFFF
 */
 
+_SRAM_SIZE = 192;
+
 MEMORY
 {
     FLASH (rx)         : ORIGIN = 0x08000000, LENGTH = 16K
     FLASH_CONFIG (r)   : ORIGIN = 0x08004000, LENGTH = 16K
     FLASH1 (rx)        : ORIGIN = 0x08008000, LENGTH = 992K
     SYSTEM_MEMORY (rx) : ORIGIN = 0x1FFF0000, LENGTH = 16K
-    RAM (xrw)          : ORIGIN = 0x20000000, LENGTH = 192K
+    RAM (xrw)          : ORIGIN = 0x20000000, LENGTH = _SRAM_SIZE * 1024
     MEMORY_B1 (rx)     : ORIGIN = 0x60000000, LENGTH = 0K /* external ram */
 }
 

src/link/at32_flash_f43xm.ld

@@ -23,13 +23,15 @@
     MEM   : 0x2000 0000 -- 0x2007 FFFF
 */
 
+_SRAM_SIZE = 192;
+
 MEMORY
 {
     FLASH (rx)         : ORIGIN = 0x08000000, LENGTH = 16K
     FLASH_CONFIG (r)   : ORIGIN = 0x08004000, LENGTH = 16K
     FLASH1 (rx)        : ORIGIN = 0x08008000, LENGTH = 4000K
     SYSTEM_MEMORY (rx) : ORIGIN = 0x1FFF0000, LENGTH = 16K
-    RAM (xrw)          : ORIGIN = 0x20000000, LENGTH = 192K
+    RAM (xrw)          : ORIGIN = 0x20000000, LENGTH = _SRAM_SIZE * 1024
     MEMORY_B1 (rx)     : ORIGIN = 0x60000000, LENGTH = 0K /* external ram */
 }
 

src/main/drivers/at32/system_at32f43x.c

@@ -29,6 +29,71 @@
 #include "drivers/persistent.h"
 #include "at32f435_437_clock.h"
 
+// See RM_AT32F435_437_EN_V2.05.pdf reference manual table 5-6 for more info.
+#if 256 < TARGET_FLASH_SIZE
+#define USD_EOPB0_SRAM_CONFIG_MASK 0x7
+#else
+#define USD_EOPB0_SRAM_CONFIG_MASK 0x3
+#endif
+
+static flash_usd_eopb0_type get_sram_config(void)
+{
+    extern uint32_t _SRAM_SIZE; // Defined in linker file
+    switch ((uint32_t)&_SRAM_SIZE) {
+#if 256 == TARGET_FLASH_SIZE
+    case 448:
+        return FLASH_EOPB0_SRAM_448K;
+    case 512:
+        return FLASH_EOPB0_SRAM_512K;
+    case 384:
+    default:
+        return FLASH_EOPB0_SRAM_384K;
+#elif 448 == TARGET_FLASH_SIZE
+    case 256:
+        return FLASH_EOPB0_SRAM_256K;
+    case 320:
+        return FLASH_EOPB0_SRAM_320K;
+    case 384:
+        return FLASH_EOPB0_SRAM_384K;
+    case 448:
+        return FLASH_EOPB0_SRAM_448K;
+    case 512:
+        return FLASH_EOPB0_SRAM_512K;
+    case 192:
+    default:
+        return FLASH_EOPB0_SRAM_192K;
+#elif 1024 <= TARGET_FLASH_SIZE
+    case 128:
+        return FLASH_EOPB0_SRAM_128K;
+    case 256:
+        return FLASH_EOPB0_SRAM_256K;
+    case 320:
+        return FLASH_EOPB0_SRAM_320K;
+    case 384:
+        return FLASH_EOPB0_SRAM_384K;
+    case 448:
+        return FLASH_EOPB0_SRAM_448K;
+    case 512:
+        return FLASH_EOPB0_SRAM_512K;
+    case 192:
+    default:
+        return FLASH_EOPB0_SRAM_192K;
+#endif
+    }
+}
+
+static void init_sram_config(void)
+{
+    // Make sure the SRAM config is correct
+    const flash_usd_eopb0_type sram_cfg = get_sram_config();
+    if (((USD->eopb0) & USD_EOPB0_SRAM_CONFIG_MASK) != sram_cfg) {
+        flash_unlock();
+        flash_user_system_data_erase();
+        flash_eopb0_config(sram_cfg);
+        systemReset();
+    }
+}
+
 void systemReset(void)
 {
     __disable_irq();
@@ -96,6 +161,8 @@ bool isMPUSoftReset(void)
 
 void systemInit(void)
 {
+    init_sram_config();
+
     persistentObjectInit();
 
     checkForBootLoaderRequest();