微電腦 - Zipit Z2 - 如何使用JTAG燒錄U-Boot


參考資訊：
http://sweetlilmre.blogspot.com/2010/08/zipit-z2-jtag.html?m=1
https://mozzwald.com/articles/using-a-raspberry-pi-as-a-jtag-debugger-to-recover-a-bricked-zipit

連接JTAG和Zipit Z2


Debian 9(x64) 

$ cd
$ sudo apt-get update
$ sudo apt-get install openocd
$ vim olimex-arm-usb-ocd-h.cfg
    interface ftdi
    ftdi_device_desc "Olimex OpenOCD JTAG ARM-USB-OCD-H"
    ftdi_vid_pid 0x15ba 0x002b

    ftdi_layout_init 0x0908 0x0b1b
    ftdi_layout_signal nSRST -oe 0x0200
    ftdi_layout_signal nTRST -data 0x0100
    ftdi_layout_signal LED -data 0x0800

    adapter_nsrst_delay 0
    jtag_ntrst_delay 200
    reset_config trst_and_srst separate
    adapter_khz 16


$ vim z2.cfg
    jtag newtap pxa270 cpu -irlen 7 -ircapture 0x1 -irmask 0x7f -expected-id 0x49265013 -expected-id 0x79265013
    target create pxa270.cpu xscale -endian little -chain-position pxa270.cpu
    pxa270.cpu configure -work-area-phys 0x5c000000 -work-area-size 0x10000 -work-area-backup 0
    flash bank pxa270.flash cfi 0x00000000 0x1000000 2 2 pxa270.cpu


$ sudo openocd -f olimex-arm-usb-ocd-h.cfg -f z2.cfg
    Open On-Chip Debugger 0.9.0 (2018-01-21-13:43)
    Licensed under GNU GPL v2
    For bug reports, read
      http://openocd.org/doc/doxygen/bugs.html
      adapter_nsrst_delay: 0
      Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
      jtag_ntrst_delay: 200
      trst_and_srst separate srst_gates_jtag trst_push_pull srst_open_drain connect_deassert_srst
      adapter speed: 16 kHz
      Info : pxa270.cpu: hardware has 2 breakpoints and 2 watchpoints
      Info : clock speed 16 kHz
      Info : JTAG tap: pxa270.cpu tap/device found: 0x79265013 (mfg: 0x009, part: 0x9265, ver: 0x7)


$ telnet localhost 4444
    Trying ::1...
    Trying 127.0.0.1...
    Connected to localhost.
    Escape character is '^]'.
    Open On-Chip Debugger

> reset halt                                 
    JTAG tap: pxa270.cpu tap/device found: 0x79265013 (mfg: 0x009, part: 0x9265, ver: 0x7)
    Bad value '00' captured during DR or IR scan:
     check_value: 0x02
     check_mask: 0x07
    JTAG error while writing DCSR
    target state: halted
    target halted in ARM state due to debug-request, current mode: Supervisor
    cpsr: 0x180000d3 pc: 0x00000000
    MMU: disabled, D-Cache: disabled, I-Cache: disabled
    (processor reset)

> flash probe 0                              
    Flash Manufacturer/Device: 0x0089 0x8865
    configuration specifies 0x1000000 size, but a 0x800000 size flash was found
    flash 'cfi' found at 0x00000000

> flash write_image erase unlock u-boot.bin 0
    auto erase enabled
    auto unlock enabled
    wrote 131072 bytes from file u-boot.bin in 98.155098s (1.304 KiB/s)