Improve flashfs codegen by fixing pagesize at a constant 256 bytes

src/main/drivers/flash.h

@@ -23,7 +23,7 @@ typedef struct flashGeometry_t {
     uint16_t sectors; // Count of the number of erasable blocks on the device
 
     uint16_t pagesPerSector;
-    uint16_t pageSize; // In bytes
+    const uint16_t pageSize; // In bytes
 
     uint32_t sectorSize; // This is just pagesPerSector * pageSize
 

src/main/drivers/flash_m25p16.c

@@ -55,7 +55,7 @@
 #define SECTOR_ERASE_TIMEOUT_MILLIS  5000
 #define BULK_ERASE_TIMEOUT_MILLIS    21000
 
-static flashGeometry_t geometry;
+static flashGeometry_t geometry = {.pageSize = M25P16_PAGESIZE};
 
 /*
  * Whether we've performed an action that could have made the device busy for writes.
@@ -150,29 +150,27 @@ static bool m25p16_readIdentification()
     // Manufacturer, memory type, and capacity
     chipID = (in[1] << 16) | (in[2] << 8) | (in[3]);
 
+    // All supported chips use the same pagesize of 256 bytes
+
     switch (chipID) {
         case JEDEC_ID_MICRON_M25P16:
             geometry.sectors = 32;
             geometry.pagesPerSector = 256;
-            geometry.pageSize = 256;
         break;
         case JEDEC_ID_MICRON_N25Q064:
         case JEDEC_ID_WINBOND_W25Q64:
             geometry.sectors = 128;
             geometry.pagesPerSector = 256;
-            geometry.pageSize = 256;
         break;
         case JEDEC_ID_MICRON_N25Q128:
         case JEDEC_ID_WINBOND_W25Q128:
             geometry.sectors = 256;
             geometry.pagesPerSector = 256;
-            geometry.pageSize = 256;
         break;
         default:
             // Unsupported chip or not an SPI NOR flash
             geometry.sectors = 0;
             geometry.pagesPerSector = 0;
-            geometry.pageSize = 0;
 
             geometry.sectorSize = 0;
             geometry.totalSize = 0;

src/main/drivers/flash_m25p16.h

@@ -20,6 +20,8 @@
 #include <stdint.h>
 #include "flash.h"
 
+#define M25P16_PAGESIZE 256
+
 bool m25p16_init();
 
 void m25p16_eraseSector(uint32_t address);

src/main/io/flashfs.c

@@ -49,8 +49,6 @@ static uint8_t bufferHead = 0, bufferTail = 0;
 
 // The position of the buffer's tail in the overall flash address space:
 static uint32_t tailAddress = 0;
-// The index of the tail within the flash page it is inside
-static uint16_t tailIndexInPage = 0;
 
 static void flashfsClearBuffer()
 {
@@ -65,10 +63,6 @@ static bool flashfsBufferIsEmpty()
 static void flashfsSetTailAddress(uint32_t address)
 {
     tailAddress = address;
-
-    if (m25p16_getGeometry()->pageSize > 0) {
-        tailIndexInPage = tailAddress % m25p16_getGeometry()->pageSize;
-    }
 }
 
 void flashfsEraseCompletely()
@@ -154,8 +148,6 @@ static uint32_t flashfsTransmitBufferUsed()
  */
 static uint32_t flashfsWriteBuffers(uint8_t const **buffers, uint32_t *bufferSizes, int bufferCount, bool sync)
 {
-    const flashGeometry_t *geometry = m25p16_getGeometry();
-
     uint32_t bytesTotal = 0;
 
     int i;
@@ -178,8 +170,8 @@ static uint32_t flashfsWriteBuffers(uint8_t const **buffers, uint32_t *bufferSiz
          * Each page needs to be saved in a separate program operation, so
          * if we would cross a page boundary, only write up to the boundary in this iteration:
          */
-        if (tailIndexInPage + bytesTotalRemaining > geometry->pageSize) {
+        if (tailAddress % M25P16_PAGESIZE + bytesTotalRemaining > M25P16_PAGESIZE) {
-            bytesTotalThisIteration = geometry->pageSize - tailIndexInPage;
+            bytesTotalThisIteration = M25P16_PAGESIZE - tailAddress % M25P16_PAGESIZE;
         } else {
             bytesTotalThisIteration = bytesTotalRemaining;
         }