feat: Add OpenOCD script to reboot SiFive P550 board

This script uses the modern 'reset_config' command to reliably
trigger a hardware reset (nSRST) for the P550 board.

openocd-reboot.cfg

@@ -0,0 +1,54 @@
+# OpenOCD Configuration to REBOOT a SiFive HiFive Pro P550 Board
+
+# ----------------------------------------------------------------
+# 1. Adapter and Board Configuration
+# ----------------------------------------------------------------
+adapter driver ftdi
+ftdi channel 2
+ftdi vid_pid 0x0403 0x6011
+ftdi layout_init 0x0808 0x0a1b
+ftdi layout_signal nSRST -oe 0x0200
+ftdi layout_signal nTRST -data 0x0100 -oe 0x0100
+
+# ----------------------------------------------------------------
+# 2. JTAG Chain and Target Configuration
+# ----------------------------------------------------------------
+transport select jtag
+set _CHIPNAME riscv
+jtag newtap $_CHIPNAME cpu -irlen 5 ;# P550 has an IR length of 5
+
+# Define the 4 P550 cores
+target create riscv.cpu0 riscv -chain-position $_CHIPNAME.cpu -coreid 0
+target create riscv.cpu1 riscv -chain-position $_CHIPNAME.cpu -coreid 1
+target create riscv.cpu2 riscv -chain-position $_CHIPNAME.cpu -coreid 2
+target create riscv.cpu3 riscv -chain-position $_CHIPNAME.cpu -coreid 3
+
+# Group the cores for simultaneous operations like halt/resume
+target smp riscv.cpu0 riscv.cpu1 riscv.cpu2 riscv.cpu3
+
+# ----------------------------------------------------------------
+# 3. Reset Configuration and Execution
+# ----------------------------------------------------------------
+
+# This is the key command. It tells OpenOCD that a "reset" should
+# assert (pull low) the nSRST signal.
+# srst_only: Asserts only nSRST, not nTRST (JTAG reset).
+# srst_pulls_trst: Informs OpenOCD that the board hardware ties nSRST and nTRST together.
+reset_config srst_only srst_pulls_trst
+
+# Initialize OpenOCD and connect to the target
+init
+
+# Halt the cores to gain control
+halt
+
+# This command now triggers the nSRST signal as configured above.
+# It will pulse the reset line, causing a full hardware reboot.
+echo "!!! Pulsing system reset (nSRST) to reboot the board..."
+reset
+
+# Optional: If you want the board to start running immediately after reboot
+# resume
+
+# Exit OpenOCD
+shutdown