Updated WEEK03

drivers/0x01_uart_cbm/Src/rp2350_reset_handler.c

@@ -38,10 +38,38 @@
 
 extern int main(void);
 
+extern uint32_t __data_lma;
+extern uint32_t __data_start;
+extern uint32_t __data_end;
+extern uint32_t __bss_start;
+extern uint32_t __bss_end;
+
+static void _data_copy_init(void)
+{
+  uint32_t *src = &__data_lma;
+  uint32_t *dst = &__data_start;
+  while (dst < &__data_end)
+    *dst++ = *src++;
+}
+
+static void _bss_zero_init(void)
+{
+  uint32_t *dst = &__bss_start;
+  while (dst < &__bss_end)
+    *dst++ = 0U;
+}
+
+void _ram_init(void)
+{
+  stack_init();
+  _data_copy_init();
+  _bss_zero_init();
+}
+
 void __attribute__((naked, noreturn)) Reset_Handler(void)
 {
   __asm__ volatile (
-    "bl stack_init\n\t"
+    "bl _ram_init\n\t"
     "bl xosc_init\n\t"
     "bl xosc_enable_peri_clk\n\t"
     "bl reset_init_subsystem\n\t"

drivers/0x01_uart_cbm/linker.ld

@@ -50,6 +50,7 @@ MEMORY
 PHDRS
 {
   text PT_LOAD FLAGS(5);
+  data PT_LOAD FLAGS(6);
 }
 
 /**
@@ -94,6 +95,35 @@ SECTIONS
     KEEP(*(.embedded_block))
   } > FLASH :text
 
+  /**
+    * Initialized data and RAM-resident code (LMA in flash, VMA in RAM).
+    * Startup copies from __data_lma to __data_start..__data_end.
+    */
+  .data :
+  {
+    . = ALIGN(4);
+    __data_start = .;
+    *(.ram_func*)
+    *(.data*)
+    . = ALIGN(4);
+    __data_end = .;
+  } > RAM AT> FLASH :data
+
+    __data_lma = LOADADDR(.data);
+
+  /**
+    * Uninitialized data (BSS) in RAM.
+    */
+  .bss (NOLOAD) :
+  {
+    . = ALIGN(4);
+    __bss_start = .;
+    *(.bss*)
+    *(COMMON)
+    . = ALIGN(4);
+    __bss_end = .;
+  } > RAM
+
   /**
     * Non-secure stack symbols.
     */