OpenOCD arp_examine 使用

因为我们很多时候运行 Openocd 的时候有些 core 还没有启动, 所以最好在配置脚本中添加 -defer-examine这个参数, 如下：

#cortex-m33
target create ${_CHIPNAME}.m33 cortex_m -dap ${_CHIPNAME}.dap -ap-num 0x6B240000 -dbgbase 0xE000E000 -defer-examine

添加完之后，在启动Openocd之后：

> Connection closed by foreign host.
zhugong@:~/workbase/openocd/$ telnet 127.0.0.1 8888
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Open On-Chip Debugger
> targets
    TargetName         Type       Endian TapName            State
--  ------------------ ---------- ------ ------------------ ------------
 0  debug.a53.0        aarch64    little debug.cpu          examine deferred
 1  debug.a53.1        aarch64    little debug.cpu          examine deferred
 2  debug.a53.2        aarch64    little debug.cpu          examine deferred
 3  debug.a53.3        aarch64    little debug.cpu          examine deferred
 4  debug.a78.0        aarch64    little debug.cpu          examine deferred
 5  debug.a78.1        aarch64    little debug.cpu          examine deferred
 6  debug.a78.2        aarch64    little debug.cpu          examine deferred
 7  debug.a78.3        aarch64    little debug.cpu          examine deferred
 8  debug.m33          cortex_m   little debug.cpu          examine deferred
 9  debug.m33_ahb      mem_ap     little debug.cpu          running

在使用某个AP的时候需要先手动做arp_examine，否则会报错Target not examined yet，如下图所示：

> targets debug.axi
> mdw 0x88000000 4
Target not examined yet

添加过 -defer-examine参数之后可以使用下面类似的命令 enable 这个AP：

> debug.axi arp_examine
> debug.axi mdw 0x80000000 4
0x80000000: 00000000 00000000 00000000 00000000