Add 'applet' make file target

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "files.associations": {}
+}

Makefile

@@ -115,6 +115,15 @@ clean:
 gdb:
 	arm-none-eabi-gdb $(BUILD_PATH)/$(NAME).elf
 
+tui:
+	arm-none-eabi-gdb -tui $(BUILD_PATH)/$(NAME).elf
+
+applet: $(EXECUTABLE)
+	rm -f flash.asm
+	arm-none-eabi-objdump -d $(BUILD_PATH)/flash.o > flash.asm
+	node scripts/genapplet.js flash.asm flash_write
+	@rm -f flash.asm
+
 drop-board: all
 	@echo "*** Copy files for $(BOARD)"
 	mkdir -p build/drop

scripts/genapplet.js

@@ -0,0 +1,36 @@
+let fs = require("fs")
+let s = fs.readFileSync(process.argv[2], "utf8")
+let pref = ""
+let infun = false
+let words = []
+for (let l of s.split(/\n/)) {
+    let m = /^00000000 <(.*)>:/.exec(l)
+    if (m && m[1] == process.argv[3]) infun = true
+    if (/^Disassembly/.test(l)) infun = false
+    if (!infun) continue
+    m = /^\s*[0-9a-f]+:\s+([0-9a-f]+)\s+/.exec(l)
+    if (m) {
+        let n = m[1]
+        if (n.length == 4) {
+            if (pref) {
+                words.push("0x" + n + pref)
+                pref = ""
+            } else {
+                pref = n
+            }
+        } else if (n.length == 8) {
+            if (pref) throw new Error()
+            words.push("0x" + n)
+        } else {
+            throw new Error()
+        }
+    }
+}
+
+let r = ""
+for (let i = 0; i < words.length; i++) {
+    if (i%6 == 0) r += "\n"
+    r += words[i] + ", "
+}
+
+console.log(r)

src/flash.c

@@ -1,9 +1,9 @@
 #include "uf2.h"
 
-static inline void wait_ready(void) {
-    while (NVMCTRL->INTFLAG.bit.READY == 0) {
-    }
-}
+// this actually generates less code than a function
+#define wait_ready()                                                                               \
+    while (NVMCTRL->INTFLAG.bit.READY == 0)                                                        \
+        ;
 
 void flash_erase_row(uint32_t *dst) {
     wait_ready();
@@ -44,6 +44,35 @@ void flash_write_words(uint32_t *dst, uint32_t *src, uint32_t n_words) {
     }
 }
 
+void flash_write() {
+    uint32_t *src = (void *)0x20006000;
+    uint32_t *dst = (void *)*src++;
+    uint32_t n_pages = *src++;
+
+    NVMCTRL->CTRLB.bit.MANW = 1;
+    while (n_pages--) {
+        wait_ready();
+        NVMCTRL->STATUS.reg = NVMCTRL_STATUS_MASK;
+
+        // Execute "ER" Erase Row
+        NVMCTRL->ADDR.reg = (uint32_t)dst / 2;
+        NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_ER;
+        wait_ready();
+
+        // Execute "PBC" Page Buffer Clear
+        NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_PBC;
+        wait_ready();
+
+        uint32_t len = FLASH_ROW_SIZE >> 2;
+        while (len--)
+            *dst++ = *src++;
+
+        // Execute "WP" Write Page
+        NVMCTRL->CTRLA.reg = NVMCTRL_CTRLA_CMDEX_KEY | NVMCTRL_CTRLA_CMD_WP;
+        wait_ready();
+    }
+}
+
 // Skip writing blocks that are identical to the existing block.
 // only disable for debugging/timing
 #define QUICK_FLASH 1