yes! hahaha... YES!!

(it compiles & works now)

.gitignore

@@ -0,0 +1,3 @@
+build/
+cmake-build/
+probe.pio.h

src/cdc_sump.h

@@ -0,0 +1,62 @@
+#ifndef CDC_SUMP_H
+#define CDC_SUMP_H
+
+#define SUMP_META_END 0
+#define SUMP_META_NAME 1
+#define SUMP_META_FPGA_VERSION 2
+#define SUMP_META_CPU_VERSION 3
+#define SUMP_META_SAMPLE_RAM 0x21
+#define SUMP_META_SAMPLE_RATE 0x23
+#define SUMP_META_PROBES_B 0x40
+#define SUMP_META_PROTOCOL_B 0x41
+
+#define SUMP_FLAG1_DDR (1<<0) /* "demux", apparently */
+#define SUMP_FLAG1_GR0_DISABLE (1<<2)
+#define SUMP_FLAG1_GR1_DISABLE (1<<3)
+#define SUMP_FLAG1_GR2_DISABLE (1<<4)
+#define SUMP_FLAG1_GR3_DISABLE (1<<5)
+#define SUMP_FLAG1_ENABLE_RLE (1<<8)
+#define SUMP_FLAG1_EXT_TEST (1<<10)
+
+#define SUMP_CMD_RESET 0
+#define SUMP_CMD_ARM 1
+#define SUMP_CMD_ID 2
+#define SUMP_CMD_META 4
+#define SUMP_CMD_FINISH 5
+
+/* demon core extensions */
+#define SUMP_CMD_QUERY_INPUT 6
+#define SUMP_CMD_ADVANCED_ARM 0xF
+
+#define SUMP_CMD_SET_SAMPLE_RATE 0x80
+#define SUMP_CMD_SET_COUNTS 0x81
+#define SUMP_CMD_SET_FLAGS 0x82
+
+/* demon core extensiosns */
+#define SUMP_CMD_SET_ADV_TRG_SELECT 0x9E
+#define SUMP_CMD_SET_ADV_TRG_DATA 0x9F
+
+#define SUMP_CMD_SET_BTRG0_MASK 0xC0
+#define SUMP_CMD_SET_BTRG1_MASK 0xC4
+#define SUMP_CMD_SET_BTRG2_MASK 0xC8
+#define SUMP_CMD_SET_BTRG3_MASK 0xCC
+#define SUMP_CMD_SET_BTRG0_VALUE 0xC1
+#define SUMP_CMD_SET_BTRG1_VALUE 0xC5
+#define SUMP_CMD_SET_BTRG2_VALUE 0xC9
+#define SUMP_CMD_SET_BTRG3_VALUE 0xCD
+#define SUMP_CMD_SET_BTRG0_CONFIG 0xC2
+#define SUMP_CMD_SET_BTRG1_CONFIG 0xC6
+#define SUMP_CMD_SET_BTRG2_CONFIG 0xCA
+#define SUMP_CMD_SET_BTRG3_CONFIG 0xCE
+
+inline static int SUMP_CMD_IS_SHORT(int cmd) {
+	return !(cmd & 0x80); // crude but works
+}
+
+void __isr sump_dma_irq_handler(void);
+void sump_rx(uint8_t *buf, uint count);
+void cdc_sump_init(void);
+void cdc_sump_task(void);
+void cdc_sump_line_coding(cdc_line_coding_t const *line_coding);
+
+#endif

src/get_serial.c

@@ -24,7 +24,8 @@
  */
 
 #include <stdint.h>
-#include "pico/unique_id.h"
+#include <pico/stdlib.h>
+#include <pico/unique_id.h>
 #include "get_serial.h"
 
 /* C string for iSerialNumber in USB Device Descriptor, two chars per byte + terminating NUL */