Add support for debugging using Raspberry Pi 4 (OCD-435)

tcl/interface/raspberrypi4-native.cfg

@@ -0,0 +1,40 @@
+#
+# Config for using Raspberry Pi 4's expansion header
+#
+# This is best used with a fast enough buffer but also
+# is suitable for direct connection if the target voltage
+# matches RPi's 3.3V and the cable is short enough.
+#
+# Do not forget the GND connection, pin 6 of the expansion header.
+#
+
+interface bcm2835gpio
+
+bcm2835gpio_peripheral_base 0xFE000000
+
+# Transition delay calculation: SPEED_COEFF/khz - SPEED_OFFSET
+# These depend on system clock, calibrated for stock 700MHz
+# bcm2835gpio_speed SPEED_COEFF SPEED_OFFSET
+# bcm2835gpio_speed_coeffs 236181 60
+bcm2835gpio_speed_coeffs 236181 60
+
+# Each of the JTAG lines need a gpio number set: tck tms tdi tdo
+# Header pin numbers: 25 27 26 24 (need to be set in Alt4 mode, might also
+# need to have `enable_jtag_gpio=1` set in /boot/firmware/config.txt)
+bcm2835gpio_jtag_nums 25 27 26 24
+
+# Each of the SWD lines need a gpio number set: swclk swdio
+# Header pin numbers: 23 22
+bcm2835gpio_swd_nums 11 25
+
+# If you define trst or srst, use appropriate reset_config
+# Header pin numbers: TRST - 26, SRST - 18
+
+# bcm2835gpio_trst_num 7
+# reset_config trst_only
+
+# bcm2835gpio_srst_num 24
+# reset_config srst_only srst_push_pull
+
+# or if you have both connected,
+# reset_config trst_and_srst srst_push_pull