# OpenOCD script for GD32VF103 with improved reset procedure

# Invoke it like this.
# for Digilent HS2
# openocd -f interface/ftdi/digilent-hs2.cfg -c "ftdi_device_desc {Digilent USB Device}" -f gd32vf103.cfg -c "program binary.elf verify reset exit"
# openocd -f interface/ftdi/digilent-hs2.cfg -c "ftdi_device_desc {Digilent USB Device}" -f gd32vf103.cfg -c "program binary.bin 0x08000000 verify reset exit"
# openocd -f interface/ftdi/digilent-hs2.cfg -c "ftdi_device_desc {Digilent USB Device}" -f gd32vf103.cfg -c "init; reset run; exit"

# for SiPEED USB-JTAG/TTL ( RV-Debugger )
# openocd -f interface/ftdi/minimodule.cfg -c "ftdi_device_desc {Dual RS232}" -f gd32vf103.cfg -c "init; reset run; exit"

# for SiPEED RV-Debugger Lite
# openocd -f interface/ftdi/minimodule.cfg -c "ftdi_device_desc {Sipeed-Debug}" -f gd32vf103.cfg -c "init; reset run; exit"

# for SiPEED RV-Debugger Plus ( BL702 )
# openocd -f interface/ftdi/minimodule.cfg -c "ftdi_device_desc {JTAG Debugger}" -f gd32vf103.cfg -c "init; reset run; exit"

#if [string equal [adapter name] ftdi] {
#    # Digilent HS2 can go upto 60MHz clock rate with this command enabled: "ftdi_tdo_sample_edge falling"
#    # ftdi_tdo_sample_edge falling
#    adapter speed 20000
#} else {
#    adapter speed 4000
#}

#transport select jtag

set _CHIPNAME riscv
# True value of GD32VF103 core's IDCODE is 0x1000563d. But it could be masqueraded in some cases.
jtag newtap $_CHIPNAME cpu -irlen 5 -expected-id 0x1000563d -expected-id 0x1e200a6d
jtag newtap gd32v tap -irlen 5 -expected-id 0x790007a3

set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME riscv -chain-position $_TARGETNAME

# Work-area is a space in RAM used for flash programming
if { [info exists WORKAREASIZE] } {
   set _WORKAREASIZE $WORKAREASIZE
} else {
   set _WORKAREASIZE 0x5000
}

$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0

# Expose Nuclei self-defined CSRS range
# # See https://github.com/riscv/riscv-gnu-toolchain/issues/319#issuecomment-358397306
# # Then user can view the csr register value in gdb using: info reg csr775 for CSR MTVT(0x307)
riscv expose_csrs 770-800,835-850,1984-2032,2064-2070


$_TARGETNAME riscv set_reset_timeout_sec 1

set _FLASHNAME $_CHIPNAME.flash
if {[catch {flash bank $_FLASHNAME stm32f1x 0x08000000 0 0 0 $_TARGETNAME}] != 0} {
    echo "** Maybe flash driver for gd32vf103 is not implemented in this version of OpenOCD **"
    echo "** You may still be able to debug target application already in the flash memory. **"
}

# riscv expose_csrs 3040-3071

proc SystemReset {} {
    global _TARGETNAME

    if {[catch {init}] != 0} {
        echo "** OpenOCD init failed **"
        shutdown error
    }

    if ![string equal halted [$_TARGETNAME curstate]] {
        halt
    }

# See gd32vf103_eclic.c for eclic_system_reset() .
# void eclic_system_reset(void) {
#     REG32(REG_DBGMCU2EN) = 0x4b5a6978;
#     REG32(REG_DBGMCU2) = 0x1;
# }
    mww 0xe004200c 0x4b5a6978
    mww 0xe0042008 0x01

    # resume
    # set dmcontrol [dmi_read 0x10]
    # dmi_write 0x10 [expr ${dmcontrol} | 0x40000000]
    # sleep 100
    # set dmstatus [dmi_read 0x11]
    # echo [format "dmstatus %08X" ${dmstatus}]
    shutdown
}

proc dmi_read {reg} {
    global _TARGETNAME
    # You don't need this treatment if you are using latest openocd
    set value [capture {$_TARGETNAME riscv dmi_read ${reg}}]
    string trimright ${value} \n
}

proc dmi_write {reg value} {
    global _TARGETNAME
    $_TARGETNAME riscv dmi_write ${reg} ${value}
}

proc dmi_write_register {regno data0} {
    dmi_write 0x04 ${data0}
    set command [expr {0x00230000 | ${regno}}]
    dmi_write 0x17 ${command}
    set abstractcs [dmi_read 0x16]
    # echo [format "abstractcs %08X" ${abstractcs}]
    if {(${abstractcs} & 0x0700) == 0} {
        # echo [format "register write OK: %04X %08X" ${regno} ${data0}]
    } else {
        echo [format "register write NG: %04X %08X" ${regno} ${data0}]
        shutdown
    }
}

proc dmi_read_register {regno} {
    set command [expr {0x00220000 | ${regno}}]
    dmi_write 0x17 ${command}
    set abstractcs [dmi_read 0x16]
    # echo [format "abstractcs %08X" ${abstractcs}]
    if {(${abstractcs} & 0x0700) == 0} {
        set data0 [dmi_read 0x04]
        # echo [format "register read OK: %04X %08X" ${regno} ${data0}]
    } else {
        echo [format "register read NG: %04X" ${regno}]
        #shutdown
        exit
    }
    return ${data0}
}

proc clear_interrupt_level_by_dmi {} {
    # progbuf0 = auipc  a0, 0x0 (0x00000517)
    dmi_write 0x20 0x00000517
    # progbuf1 = ebreak (0x00100073)
    dmi_write 0x21 0x00100073

    # command = postexec
    dmi_write 0x17 0x00040000
    set abstractcs [dmi_read 0x16]
    if {(${abstractcs} & 0x0700) == 0} {
        # echo [format "Debug : exec auipc OK"]
    } else {
        echo [format "Debug : exec auipc NG"]
        echo [format "Debug : abstractcs %08X" ${abstractcs}]
        exit
    }

    #  a0 has been loaded with address of progbuf0
    set a0 [dmi_read_register 0x100A]
    # mepc = &progbuf1
    dmi_write_register 0x0341 [expr ${a0} + 4]

    # progbuf0 = mret (0x30200073)
    dmi_write 0x20 0x30200073

    # command = postexec
    dmi_write 0x17 0x00040000
    set abstractcs [dmi_read 0x16]
    if {(${abstractcs} & 0x0700) == 0} {
        # echo [format "Debug : exec mret OK"]
    } else {
        echo [format "Debug : exec mret NG"]
        echo [format "Debug : abstractcs %08X" ${abstractcs}]
        exit
    }
}

proc reset_by_dmi {args} {
    global _TARGETNAME
    set curstate [$_TARGETNAME curstate]
    # echo [format "curstate = %s" ${curstate}]
    if ![string equal ${curstate} halted] {
        halt
    }
    # Reset all peripherals
    # RCU_APB1RST
    mww 0x40021010 0xFFFFFFFF
    mww 0x40021010 0x00000000
    # RCU_APB2RST
    mww 0x4002100C 0xFFFFFFFF
    mww 0x4002100C 0x00000000
    # RCU_AHBRST (USBFSRST)
    mww 0x40021028 0xFFFFFFFF
    mww 0x40021028 0x00000000

    # RCU_CFG0
    # echo [format "RCU_CFG0 %08X" [mrw 0x40021004]]
    mwb 0x40021004 0x00
    # echo [format "RCU_CFG0 %08X" [mrw 0x40021004]]

    # What should we do with EXTI and ECLIC ?

    set dmstatus [dmi_read 0x11]
    set impebreak [expr {(${dmstatus} & 0x00400000) >> 22}]
    # echo [format "dmstatus(DMI(0x11)) = %08X" ${dmstatus}]
    set abstractcs [dmi_read 0x16]
    set datacount [expr {(${abstractcs} & 0x0000000F)}]
    set progbufsize [expr {(${abstractcs} & 0x1F000000) >> 24}]
    # echo [format "Info : datacount=%d progbufsize=%d impebreak=%d" ${datacount} ${progbufsize} ${impebreak}]
    if {(${progbufsize} < 2) && !${impebreak}} {
        exit
    }
    # echo [format "abstractcs(DMI(0x16)) = %08X" ${abstractcs}]
    # echo [format "mstatus(0x300) = %08X" [dmi_read_register 0x0300]]
    # echo [format "mie(0x304) = %08X" [dmi_read_register 0x0304]]
    # echo [format "mepc(0x341) = %08X" [dmi_read_register 0x0341]]
    # echo [format "mcause(0x342) = %08X" [dmi_read_register 0x342]]
    set mintstatus [dmi_read_register 0x0346]
    # echo [format "Debug : mintstatus(0x346)=%08X" ${mintstatus}]
    # echo [format "msubm(0x7c4) = %08X" [dmi_read_register 0x07c4]]
    # echo [format "dcsr = %08X" [dmi_read_register 0x07B0]]
    # echo [format "dpc = %08X" [dmi_read_register 0x07B1]]
    # mstatus
    dmi_write_register 0x0300 0x00001800
    # msubm
    dmi_write_register 0x07C4 0x00000000
    if {(${mintstatus} & 0xFF000000) != 0} {
        # echo [format "a0(0x100A) = %08X" [dmi_read_register 0x100A]]
        clear_interrupt_level_by_dmi
        # echo [format "a0(0x100A) = %08X" [dmi_read_register 0x100A]]
        # echo [format "Debug : mintstatus(0x346)=%08X" [dmi_read_register 0x0346]]
    }
    #echo [format "mepc(0x341) = %08X" [dmi_read_register 0x0341]]

    # dcsr
    dmi_write_register 0x07B0 0x00000003
    # dpc
    dmi_write_register 0x07B1 0x08000000
    # mcountinhibit
    dmi_write_register 0x0320 0x00000000

    foreach arg $args {
        if [string equal [string tolower $arg] run] {
            set run 1
        }
        if [string equal [string tolower $arg] halt] {
            set halt 1
        }
        if [string equal [string tolower $arg] init] {
            set halt 1
        }
    }
    if [info exists run] {
        resume
    } elseif [info exists halt] {
    } elseif [string equal ${curstate} running] {
        resume
    }
}

rename init original_init
proc init {} {
    rename init {}
    rename original_init init
    init
    # rename reset original_reset
    rename reset {}
    proc reset {args} {
        reset_by_dmi $args
    }
}

# this will suppress value of the last expression getting printed
if 0 { }