Add shared emulator services, waveform generation and STM32 USB boot ports

c/set-protocol/ports/stm32g474-usb-boot/boot_writer.h

@@ -0,0 +1,37 @@
+#ifndef G474_BOOT_WRITER_H
+#define G474_BOOT_WRITER_H
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+/* ECC Flash must be programmed once per 64-bit word. Keep partial words in RAM
+ * across SET packets; pad only the final word, without changing the image CRC. */
+typedef bool (*g474_program_word)(void *user, uint32_t offset, uint64_t word);
+typedef struct {
+    uint32_t size, received;
+    uint8_t pending[8];
+    uint8_t used;
+    bool failed;
+} g474_writer;
+static inline void g474_writer_init(g474_writer *w, uint32_t size)
+{
+    memset(w, 0, sizeof(*w)); w->size = size;
+    memset(w->pending, 0xff, sizeof(w->pending));
+}
+static inline bool g474_writer_write(g474_writer *w, uint32_t offset,
+    const uint8_t *data, uint16_t length, g474_program_word program, void *user)
+{
+    if (w->failed || !length || offset != w->received ||
+        offset > w->size || length > w->size - offset) return false;
+    while (length--) {
+        w->pending[w->used++] = *data++; ++w->received;
+        if (w->used == 8 || w->received == w->size) {
+            uint64_t word;
+            uint32_t start = w->received - w->used;
+            memcpy(&word, w->pending, sizeof(word));
+            if (!program(user, start, word)) { w->failed = true; return false; }
+            w->used = 0; memset(w->pending, 0xff, sizeof(w->pending));
+        }
+    }
+    return true;
+}
+#endif