[cc2538] fix FLASH settings location (#2070)

examples/platforms/cc2538/cc2538-reg.h

@@ -202,7 +202,6 @@
 #define SOC_ADC_ADCCON1_RCTRL0                  0x00000004  // ADCCON1 RCTRL bit 0
 #define SOC_ADC_ADCCON1_RCTRL1                  0x00000008  // ADCCON1 RCTRL bit 1
 
-#define FLASH_BASE                              0x00200000  // Flash base address
 #define FLASH_CTRL_FCTL                         0x400D3008  // Flash control
 #define FLASH_CTRL_DIECFG0                      0x400D3014  // Flash information
 

examples/platforms/cc2538/cc2538.ld

@@ -31,12 +31,54 @@
  *   GCC linker script for CC2538.
  */
 
+_512k_bytes             = (512*1024);
+_256k_bytes             = (256*1024);
+_128k_bytes             = (128*1024);
+_FLASH_page_size        = 2048;
+
+/*
+ * Change for your chip, default is 512k chips
+ */
+_FLASH_size_bytes       = _512k_bytes;
+_FLASH_n_pages          = (_FLASH_size_bytes / _FLASH_page_size);
+/* reduce the usable size by: the CCA + settings Page A & B, total 3 pages */
+_FLASH_usable_size      = (_FLASH_size_bytes - (3 * _FLASH_page_size));
+_FLASH_start            = 0x00200000;
+_FLASH_end              = (_FLASH_start + _FLASH_size_bytes);
+
+/*
+ * The CCA (Customer Configuration Area) is always the last page.
+ * See: http://www.ti.com/lit/ug/swru319c/swru319c.pdf
+ * table 8-2 for more details.
+ */
+_FLASH_cca_page         = (_FLASH_end - (1 * _FLASH_page_size));
+
+/*
+ * OpenThread NV storage goes in the settings page.
+ * OpenThread requires at least 2 adjacent pages, call them A and B.
+ */
+_FLASH_settings_pageB   = (_FLASH_end - (2 * _FLASH_page_size));
+_FLASH_settings_pageA   = (_FLASH_end - (3 * _FLASH_page_size));
+
 MEMORY
 {
-  FLASH (rx) :           ORIGIN = 0x00200000,            LENGTH = 0x0007FFD4
-  FLASH_CCA (rx) :       ORIGIN = 0x0027FFD4,            LENGTH = 0x2C
-  SRAM (rwx) :           ORIGIN = 0x20000000,            LENGTH = 32K
+  /* would like to use SYMBOLS (from above)here but we cannot
+   * GCC version 4.9 does not support symbolic expressions here.
+   * But later versions do support the feature.
+   */
+  FLASH (rx) :     ORIGIN = 0x00200000,     LENGTH = 0x0007c000
+  FLASH_CCA (rx) : ORIGIN = 0x0027FFD4,     LENGTH = 0x2c
+  SRAM (rwx) :     ORIGIN = 0x20000000,     LENGTH = 32K
 }
+/*
+ * To safty check what would have been the SYMBOL values
+ * we use these ASSERTS to verify things are still good.
+ */
+ASSERT( _FLASH_start       == 0x00200000, "invalid flash start address for cc2538")
+ASSERT( _FLASH_cca_page    == 0x0027f800, "invalid cca start address for cc2538")
+ASSERT( _FLASH_usable_size == 0x0007e800, "Invalid usable size for this config")
+
+
 
 ENTRY(flash_cca_lock_page)
 SECTIONS

examples/platforms/cc2538/flash.c

@@ -26,25 +26,44 @@
  *  POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <openthread/config.h>
+#include <openthread-core-config.h>
+
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
-#include <openthread/config.h>
 #include <openthread/platform/alarm-milli.h>
 
 #include "platform-cc2538.h"
 #include "rom-utility.h"
 #include "utils/code_utils.h"
 #include "utils/flash.h"
+#include "utils/wrap_string.h"
 
 #define FLASH_CTRL_FCTL_BUSY   0x00000080
 
-enum
+#if SETTINGS_CONFIG_PAGE_SIZE != 2048
+#error FLASH page size is 2048 on this chip
+#endif
+
+#if SETTINGS_CONFIG_PAGE_NUM != 2
+#error Linker script reserves 2 pages for settings.
+#endif
+
+/* The linker script creates this external symbol */
+extern uint8_t _FLASH_settings_pageA[];
+
+/* Convert a settings offset to the physical address within the flash settings pages */
+static uint32_t flashPhysAddr(uint32_t settings_offset)
 {
-    FLASH_PAGE_SIZE = 0x800,
-};
+    uint32_t base;
+
+    base = (uint32_t)(&_FLASH_settings_pageA[0]);
+    base = base + settings_offset;
+    return base;
+}
 
 static otError romStatusToThread(int32_t aStatus)
 {
@@ -78,9 +97,7 @@ otError utilsFlashInit(void)
 
 uint32_t utilsFlashGetSize(void)
 {
-    uint32_t reg = (HWREG(FLASH_CTRL_DIECFG0) & 0x00000070) >> 4;
-
-    return reg ? (0x20000 * reg) : 0x10000;
+    return (SETTINGS_CONFIG_PAGE_SIZE * SETTINGS_CONFIG_PAGE_NUM);
 }
 
 otError utilsFlashErasePage(uint32_t aAddress)
@@ -91,8 +108,9 @@ otError utilsFlashErasePage(uint32_t aAddress)
 
     otEXPECT_ACTION(aAddress < utilsFlashGetSize(), error = OT_ERROR_INVALID_ARGS);
 
-    address = FLASH_BASE + aAddress - (aAddress & (FLASH_PAGE_SIZE - 1));
-    status = ROM_PageErase(address, FLASH_PAGE_SIZE);
+    address = aAddress - (aAddress & (SETTINGS_CONFIG_PAGE_SIZE - 1));
+    address = flashPhysAddr(address);
+    status = ROM_PageErase(address, SETTINGS_CONFIG_PAGE_SIZE);
     error = romStatusToThread(status);
 
 exit:
@@ -130,7 +148,7 @@ uint32_t utilsFlashWrite(uint32_t aAddress, uint8_t *aData, uint32_t aSize)
 
     while (size < aSize)
     {
-        status = ROM_ProgramFlash(data, aAddress + FLASH_BASE, 4);
+        status = ROM_ProgramFlash(data, flashPhysAddr(aAddress), 4);
 
         while (busy)
         {
@@ -155,8 +173,7 @@ uint32_t utilsFlashRead(uint32_t aAddress, uint8_t *aData, uint32_t aSize)
 
     while (size < aSize)
     {
-        uint32_t reg = HWREG(aAddress + FLASH_BASE);
-        uint8_t *byte = (uint8_t *)&reg;
+        uint8_t *byte = (uint8_t *)flashPhysAddr(aAddress);
         uint8_t maxIndex = 4;
 
         if (size == (aSize - aSize % 4))

examples/platforms/cc2538/openthread-core-cc2538-config.h

@@ -66,4 +66,23 @@
   */
 #define OPENTHREAD_CONFIG_ENABLE_SOFTWARE_ENERGY_SCAN          1
 
+/**
+ * @def SETTINGS_CONFIG_BASE_ADDRESS
+ *
+ * The actual physical address used for the cc2538 is set by the
+ * linker file, the value here is "relative to the base address" set
+ * in the linker file.
+ */
+#define SETTINGS_CONFIG_BASE_ADDRESS                           0
+
+/**
+ * @def The CC2538 linker script sets aside 2 pages.
+ */
+#define SETTINGS_CONFIG_PAGE_NUM                               2
+
+/**
+ * @def The page size of settings, 2K bytes
+ */
+#define SETTINGS_CONFIG_PAGE_SIZE                              2048
+
 #endif  // OPENTHREAD_CORE_CC2538_CONFIG_H_