rp23 memory.x

examples/rp-pico-2-w/memory.x

@@ -1,17 +1,75 @@
 MEMORY {
-    BOOT2 : ORIGIN = 0x10000000, LENGTH = 0x100
-    FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
+    /*
+     * The RP2350 has either external or internal flash.
+     *
+     * 2 MiB is a safe default here, although a Pico 2 has 4 MiB.
+     */
+    FLASH : ORIGIN = 0x10000000, LENGTH = 2048K
+    /*
+     * RAM consists of 8 banks, SRAM0-SRAM7, with a striped mapping.
+     * This is usually good for performance, as it distributes load on
+     * those banks evenly.
+     */
+    RAM : ORIGIN = 0x20000000, LENGTH = 512K
+    /*
+     * RAM banks 8 and 9 use a direct mapping. They can be used to have
+     * memory areas dedicated for some specific job, improving predictability
+     * of access times.
+     * Example: Separate stacks for core0 and core1.
+     */
+    SRAM4 : ORIGIN = 0x20080000, LENGTH = 4K
+    SRAM5 : ORIGIN = 0x20081000, LENGTH = 4K
+}
 
-    /* Pick one of the two options for RAM layout     */
+SECTIONS {
+    /* ### Boot ROM info
+     *
+     * Goes after .vector_table, to keep it in the first 4K of flash
+     * where the Boot ROM (and picotool) can find it
+     */
+    .start_block : ALIGN(4)
+    {
+        __start_block_addr = .;
+        KEEP(*(.start_block));
+        KEEP(*(.boot_info));
+    } > FLASH
 
-    /* OPTION A: Use all RAM banks as one big block   */
-    /* Reasonable, unless you are doing something     */
-    /* really particular with DMA or other concurrent */
-    /* access that would benefit from striping        */
-    RAM   : ORIGIN = 0x20000000, LENGTH = 264K
+} INSERT AFTER .vector_table;
 
-    /* OPTION B: Keep the unstriped sections separate */
-    /* RAM: ORIGIN = 0x20000000, LENGTH = 256K        */
-    /* SCRATCH_A: ORIGIN = 0x20040000, LENGTH = 4K    */
-    /* SCRATCH_B: ORIGIN = 0x20041000, LENGTH = 4K    */
-}
+/* move .text to start /after/ the boot info */
+_stext = ADDR(.start_block) + SIZEOF(.start_block);
+
+SECTIONS {
+    /* ### Picotool 'Binary Info' Entries
+     *
+     * Picotool looks through this block (as we have pointers to it in our
+     * header) to find interesting information.
+     */
+    .bi_entries : ALIGN(4)
+    {
+        /* We put this in the header */
+        __bi_entries_start = .;
+        /* Here are the entries */
+        KEEP(*(.bi_entries));
+        /* Keep this block a nice round size */
+        . = ALIGN(4);
+        /* We put this in the header */
+        __bi_entries_end = .;
+    } > FLASH
+} INSERT AFTER .text;
+
+SECTIONS {
+    /* ### Boot ROM extra info
+     *
+     * Goes after everything in our program, so it can contain a signature.
+     */
+    .end_block : ALIGN(4)
+    {
+        __end_block_addr = .;
+        KEEP(*(.end_block));
+    } > FLASH
+
+} INSERT AFTER .uninit;
+
+PROVIDE(start_to_end = __end_block_addr - __start_block_addr);
+PROVIDE(end_to_start = __start_block_addr - __end_block_addr);