Pollux JTAG with Wiggler

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Revision as of 21:10, 15 February 2011 by Jkent (talk | contribs)
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For now I'm just going to dump my configuration files here that I use to debug the kernel. To speed up the debug process, I use Micromon to load the kernel to memory, rather than waiting on the slow Wiggler.

Please see Pollux JTAG with FTDI or the Didj JTAG How To for more info on OpenOCD or GDB.


interface parport
parport_port 0
parport_cable wiggler
# length of reset signal: [ms]
jtag_nsrst_assert_width 100
# don't talk to JTAG after reset for: [ms]
jtag_nsrst_delay 250
reset_config trst_and_srst separate
# end reset config
# reset_config trst_only
if { [info exists CHIPNAME] } {
} else {
  set  _CHIPNAME pollux
if { [info exists ENDIAN] } {
} else {
  set  _ENDIAN little
if { [info exists CPUTAPID ] } {
} else {
  # force an error till we get a good number
  set _CPUTAPID 0x07926f0f
#jtag scan chain
jtag newtap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
target create $_TARGETNAME arm926ejs -endian $_ENDIAN -chain-position $_TARGETNAME -variant arm926ejs


define dmesg
  set $log_buf = log_buf
  set $log_end = log_end
  set $log_buf_len = log_buf_len
 set $logged_chars = logged_chars

  set $i = 0
  set $end_idx = (log_end - 1) & (log_buf_len - 1)
  while ($i < logged_chars)
    set $idx = (log_end - 1 - logged_chars + $i) & (log_buf_len - 1)
    printf "%c", log_buf[$idx]
    set $i = $i + 1
document dmesg
  print the kernel ring buffer

define reload
  # restart the target
  mon reset

  # load_kernel.py is assumed in your path, which is a
  # modified version of micromon's boot_kernel.py that
  # does not execute the kernel after loading or start
  # the console
  shell load_kernel.py arch/arm/boot/Image

  # stop the looping cpu running in Thumb mode
  mon halt

  # switch back to ARM
  mon arm core_state arm

  # this register must be 0
  mon reg r0 0

  # platform id
  mon reg r1 2028

  # -1
  mon reg r2 0xFFFFFFFF

  # kernel start address
  mon reg pc 0x00008000

  # load the symbols from the debug kernel
  symbol-file vmlinux
document reload
Resets the target and reloads the kernel, halted at the kernel entry point

target remote :3333
mon target_request debugmsgs charmsg
mon arm7_9 fast_memory_access enable
mon arm7_9 dcc_downloads enable