Manual Reference Pages - ICE-GDB (1)
ice-gdb - JTAG ICE frontend for avr-gdb
ice-insight - JTAG ICE frontend for avr-insight
New Gdb Commands
Debugging With Jtag Ice
avarice to do on-chip debugging on Atmel AVR processors using their JTAG-based
on-chip debug facilities, via the Atmel JTAG ICE pod.
The executable for the program being debugged is downloaded to the
processor unless the
--capture option is specified. A number of extra commands are available within gdb
when started, see their description in NEW GDB COMMANDS below. Restrictions
on debugging with the JTAG ICE pod are discussed in more detail in DEBUGGING
WITH JTAG ICE below.
The arguments passed to
avarice include the value of the
AVARICE_ARGS environment variable. This is typically used to specify the serial port to
which the JTAG ICE pod is connected by setting
AVARICE_ARGS to "-j <serial port name>".
--debugger debugger_command |
Specify a different debugger than avr-gdb (or avr-insight). This other
debugger should behave similarly to gdb.
Dont download the executable being debugged to the mote, just interrupt the
current program and assume that it matches the executable passed to
ice-gdb. This is similar to "attaching" to a running program within gdb.
--ignore-intr option to
avarice. The single-step commands in gdb (s, n) will then "step over" interrupt
handlers (i.e., if an interrupt occurs, execution will resume for the
duration of the interrupt).
Do not start
avr-gdb will attempt to connect to an already running
avarice on port localhost:6423.
NEW GDB COMMANDS
ice-load filename |
Download executable filename to the Atmel processor and start debugging it
(this replaces the gdb
Connect to a copy of
avarice running on port localhost:6423.
DEBUGGING WITH JTAG ICE
The JTAG ICE debugging environment has a few restrictions and changes:
No "soft" breakpoints, and only three hardware breakpoints. The break
command sets hardware breakpoints. The easiest way to deal with this
restriction is to enable and disable breakpoints as needed.
Two 1-byte hardware watchpoints (but each hardware watchpoint takes away
one hardware breakpoint). If you set a watchpoint on a variable which takes
more than one byte, execution will be abysmally slow. Instead it is better
to do the following:
watch *(char *)&myvariable
which watches the least significant byte of
The Atmel AVR processors have a Harvard architecture (separate code and
data buses). To distinguish data address 0 from code address 0,
avr-gdb adds 0x800000 to all data addresses. Bear this in mind when examining
printed pointers, or when passing absolute addresses to gdb commands.
Extra arguments to pass to
avarice at startup.
On Windows, the
ice-insight commands only work in the
cygwin environment. They do not work with the
|--> ||ICE-GDB (1) ||August 22, 2003 |
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