Firmware: Move delay functions, add M0 version of delay_us_at_mhz.

firmware/blinky/blinky.c

@@ -21,6 +21,7 @@
 
 #include "hackrf_core.h"
 #include "platform_detect.h"
+#include "delay.h"
 
 int main(void)
 {

firmware/common/delay.c

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2026 Great Scott Gadgets <info@greatscottgadgets.com>
+ *
+ * This file is part of HackRF.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "delay.h"
+
+void delay(uint32_t duration)
+{
+	uint32_t i;
+
+	for (i = 0; i < duration; i++) {
+		__asm__("nop");
+	}
+}
+
+void delay_us_at_mhz(uint32_t us, uint32_t mhz)
+{
+#if defined(LPC43XX_M4)
+	// The loop below takes 3 cycles per iteration.
+	uint32_t loop_iterations = (us * mhz) / 3;
+	asm volatile("start%=:\n"
+		     "    subs %[ITERATIONS], #1\n" // 1 cycle
+		     "    bpl start%=\n"            // 2 cycles
+		     :
+		     : [ITERATIONS] "r"(loop_iterations));
+#elif defined(LPC43XX_M0)
+	// The loop below takes 4 cycles per iteration.
+	uint32_t loop_iterations = (us * mhz) / 4;
+	asm volatile("start%=:\n"
+		     "    sub %[ITERATIONS], #1\n" // 1 cycle
+		     "    bpl start%=\n"           // 3 cycles
+		     :
+		     : [ITERATIONS] "r"(loop_iterations));
+#else
+	#error "No delay loop implementation"
+#endif
+}

firmware/common/delay.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2026 Great Scott Gadgets <info@greatscottgadgets.com>
+ *
+ * This file is part of HackRF.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __DELAY_H
+#define __DELAY_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+void delay(uint32_t duration);
+void delay_us_at_mhz(uint32_t us, uint32_t mhz);
+
+#endif /* __DELAY_H */

firmware/common/fpga_selftest.c

@@ -24,6 +24,7 @@
 #include "streaming.h"
 #include "selftest.h"
 #include "fpga.h"
+#include "delay.h"
 
 // USB buffer used during selftests.
 #define USB_BULK_BUFFER_SIZE 0x8000

firmware/common/hackrf_core.c

@@ -23,6 +23,7 @@
 
 #include "hackrf_core.h"
 #include "hackrf_ui.h"
+#include "delay.h"
 #include "sgpio.h"
 #include "si5351c.h"
 #include "spi_ssp.h"
@@ -441,26 +442,6 @@ jtag_t jtag_cpld = {
 	.gpio = &jtag_gpio_cpld,
 };
 
-void delay(uint32_t duration)
-{
-	uint32_t i;
-
-	for (i = 0; i < duration; i++) {
-		__asm__("nop");
-	}
-}
-
-void delay_us_at_mhz(uint32_t us, uint32_t mhz)
-{
-	// The loop below takes 3 cycles per iteration.
-	uint32_t loop_iterations = (us * mhz) / 3;
-	asm volatile("start%=:\n"
-		     "    subs %[ITERATIONS], #1\n" // 1 cycle
-		     "    bpl start%=\n"            // 2 cycles
-		     :
-		     : [ITERATIONS] "r"(loop_iterations));
-}
-
 /* GCD algo from wikipedia */
 /* http://en.wikipedia.org/wiki/Greatest_common_divisor */
 static uint32_t gcd(uint32_t u, uint32_t v)

firmware/common/hackrf_core.h

@@ -389,9 +389,6 @@ extern "C" {
 #define SCU_H1R9_NO_VAA_EN  (P6_10) /* GPIO3[6] on P6_10 */
 #define SCU_H1R9_TRIGGER_EN (P2_5)  /* GPIO5[5] on P2_5 */
 
-void delay(uint32_t duration);
-void delay_us_at_mhz(uint32_t us, uint32_t mhz);
-
 /* TODO: Hide these configurations */
 extern si5351c_driver_t clock_gen;
 extern const ssp_config_t ssp_config_w25q80bv;

firmware/common/ice40_spi.c

@@ -23,6 +23,7 @@
 
 #include <libopencm3/lpc43xx/scu.h>
 #include "hackrf_core.h"
+#include "delay.h"
 
 void ice40_spi_target_init(ice40_spi_driver_t* const drv)
 {

firmware/common/operacake_sctimer.c

@@ -29,6 +29,7 @@
 #include <libopencm3/lpc43xx/scu.h>
 #include <libopencm3/lpc43xx/gima.h>
 #include "sct.h"
+#include "delay.h"
 
 #define U1CTRL_SET  SCT_OUT14_SET
 #define U1CTRL_CLR  SCT_OUT14_CLR

firmware/common/platform_detect.c

@@ -23,6 +23,7 @@
 #include "firmware_info.h"
 #include "gpio_lpc.h"
 #include "hackrf_core.h"
+#include "delay.h"
 #include "adc.h"
 
 #include <libopencm3/lpc43xx/scu.h>

firmware/common/portapack.c

@@ -24,6 +24,7 @@
 
 #include "hackrf_core.h"
 #include "gpio_lpc.h"
+#include "delay.h"
 
 #include <libopencm3/lpc43xx/scu.h>
 

firmware/common/rad1o/display.c

@@ -2,6 +2,7 @@
 
 #include "gpio_lpc.h"
 #include "hackrf_core.h"
+#include "delay.h"
 
 #include <libopencm3/lpc43xx/scu.h>
 #include <libopencm3/lpc43xx/ssp.h>

firmware/common/rffc5071.c

@@ -39,6 +39,7 @@
 
 #include <libopencm3/lpc43xx/scu.h>
 #include "hackrf_core.h"
+#include "delay.h"
 
 /* Default register values from vendor documentation or software. */
 static const uint16_t rffc5071_regs_default[RFFC5071_NUM_REGS] = {

firmware/hackrf-common.cmake

@@ -168,6 +168,7 @@ endmacro()
 macro(DeclareTargets)
 	SET(SRC_M4
 		${SRC_M4}
+		${PATH_HACKRF_FIRMWARE_COMMON}/delay.c
 		${PATH_HACKRF_FIRMWARE_COMMON}/hackrf_core.c
 		${PATH_HACKRF_FIRMWARE_COMMON}/sgpio.c
 		${PATH_HACKRF_FIRMWARE_COMMON}/rf_path.c

firmware/hackrf_usb/hackrf_usb.c

@@ -62,6 +62,7 @@
 #include "clkin.h"
 #include "fpga.h"
 #include "selftest.h"
+#include "delay.h"
 
 extern uint32_t __m0_start__;
 extern uint32_t __m0_end__;