riscv-openocd/tcl/target/ar71xx.cfg

# Atheros AR71xx MIPS 24Kc SoC.
# tested on PB44 refererence board

jtag_nsrst_delay 100
jtag_ntrst_delay 100

reset_config trst_and_srst

set CHIPNAME ar71xx

jtag newtap $CHIPNAME cpu -irlen 5 -ircapture 0x1 -irmask 0x1f -expected-id 1

set TARGETNAME [format "%s.cpu" $CHIPNAME]
target create $TARGETNAME mips_m4k -endian big -chain-position $TARGETNAME

$TARGETNAME configure -event reset-halt-post {
	#setup PLL to lowest common denominator 300/300/150 setting
	mww 0xb8050000 0x000f40a3	# reset val + CPU:3 DDR:3 AHB:0
	mww 0xb8050000 0x800f40a3	# send to PLL

	#next command will reset for PLL changes to take effect
	mww 0xb8050008 3		# set reset_switch and clock_switch (resets SoC)
}

$TARGETNAME configure -event reset-init {
	#complete pll initialization
	mww 0xb8050000 0x800f0080	# set sw_update bit
	mww 0xb8050008 0		# clear reset_switch bit
	mww 0xb8050000 0x800f00e8       # clr pwrdwn & bypass
	mww 0xb8050008 1		# set clock_switch bit
	sleep 1                         # wait for lock
	
	# Setup DDR config and flash mapping
	mww 0xb8000000 0xefbc8cd0       # DDR cfg cdl val (rst: 0x5bfc8d0)
	mww 0xb8000004 0x8e7156a2       # DDR cfg2 cdl val (rst: 0x80d106a8)
	
	mww 0xb8000010 8		# force precharge all banks
	mww 0xb8000010 1 		# force EMRS update cycle
	mww 0xb800000c 0                # clr ext. mode register
	mww 0xb8000010 2 		# force auto refresh all banks
	mww 0xb8000010 8		# force precharge all banks
	mww 0xb8000008 0x31             # set DDR mode value CAS=3
	mww 0xb8000010 1 		# force EMRS update cycle
	mww 0xb8000014 0x461b           # DDR refresh value
	mww 0xb8000018 0xffff           # DDR Read Data This Cycle value (16bit: 0xffff)
	mww 0xb800001c 0x7              # delay added to the DQS line (normal = 7)
	mww 0xb8000020 0
	mww 0xb8000024 0
	mww 0xb8000028 0
}	

# setup working area somewhere in RAM
$TARGETNAME configure -work-area-phys 0xa0600000 -work-area-size 0x20000

# serial SPI capable flash
# flash bank <driver> <base> <size> <chip_width> <bus_width>