[ion] Define FRAMEBUFFER_LENGTH

ion/platform/device/display.c

@@ -17,6 +17,7 @@
  */
 
 #include <ion.h>
+#include <string.h>
 
 #include "display/gpio.h"
 #include "display/spi.h"
@@ -52,5 +53,13 @@ void init_display() {
 
   st7586_set_display_area(controller, 0, FRAMEBUFFER_WIDTH, 0, FRAMEBUFFER_HEIGHT);
 
+  st7586_enable_frame_data_upload(controller);
+
+  memset(FRAMEBUFFER_ADDRESS, 0, FRAMEBUFFER_LENGTH);
+
+  for (int i=0;i<10;i++) {
+    ion_set_pixel(i,i,0x3);
+  }
+
   display_dma_init();
 }

ion/platform/device/display/dma.c

@@ -1,11 +1,10 @@
 #include "../registers/registers.h"
+#include "../framebuffer.h"
 
 // DMA 1, channel 0, stream 4 = SPI2_TX
 #define LCD_DMA_CHANNEL 0
 #define LCD_DMA_STREAM 4
 
-extern char _framebuffer_start, _framebuffer_end;
-
 void display_dma_init() {
 // 0 - ENable DMA clock!
   RCC_AHB1ENR |= DMA1EN;
@@ -20,11 +19,10 @@ void display_dma_init() {
   DMA_SPAR(DMA1,LCD_DMA_STREAM) = (uint32_t)&SPI_DR(SPI2);
 
   // 3 - Set the memory address
-  DMA_SMA0R(DMA1,LCD_DMA_STREAM) = (uint32_t)&_framebuffer_start;
+  DMA_SMA0R(DMA1,LCD_DMA_STREAM) = (uint32_t)FRAMEBUFFER_ADDRESS;
 
   // 4 - Number of data items
-  //DMA_SNDTR(DMA1,LCD_DMA_STREAM) = &_framebuffer_end-&_framebuffer_start;
-  REGISTER_SET_VALUE(DMA_SNDTR(DMA1,LCD_DMA_STREAM), DMA_SNDTR, &_framebuffer_end-&_framebuffer_start);
+  REGISTER_SET_VALUE(DMA_SNDTR(DMA1,LCD_DMA_STREAM), DMA_SNDTR, FRAMEBUFFER_LENGTH);
 
   // 5 - Select the DMA channel
   REGISTER_SET_VALUE(DMA_SCR(DMA1,LCD_DMA_STREAM), DMA_CHSEL, LCD_DMA_CHANNEL);

ion/platform/device/framebuffer.h

@@ -2,6 +2,7 @@ extern char _framebuffer_start;
 extern char _framebuffer_end;
 
 #define FRAMEBUFFER_ADDRESS (&_framebuffer_start)
+#define FRAMEBUFFER_LENGTH (&_framebuffer_end-&_framebuffer_start)
 #define FRAMEBUFFER_WIDTH 160
 #define FRAMEBUFFER_HEIGHT 160
 #define FRAMEBUFFER_BITS_PER_PIXEL 4