1ice-gdb(1) General Commands Manual ice-gdb(1)
2
6 ice-gdb - JTAG ICE frontend for avr-gdb
7 ice-insight - JTAG ICE frontend for avr-insight
8
10 ice-gdb/ice-insight [--debugger debugger] [--capture] [--ignore-intr]
11 [--external] [gdb_arguments]
12
14 ice-gdb (respectively ice-insight) starts avr-gdb (respectively avr-
15 insight) and avarice to do on-chip debugging on Atmel AVR processors
16 using their JTAG-based on-chip debug facilities, via the Atmel JTAG ICE
17 pod.
18 The executable for the program being debugged is downloaded to the pro‐
20 cessor unless the --capture option is specified. A number of extra com‐
21 mands are available within gdb when started, see their description in
22 NEW GDB COMMANDS below. Restrictions on debugging with the JTAG ICE pod
23 are discussed in more detail in DEBUGGING WITH JTAG ICE below.
24 The arguments passed to avarice include the value of the AVARICE_ARGS
26 environment variable. This is typically used to specify the serial port
27 to which the JTAG ICE pod is connected by setting AVARICE_ARGS to "-j
28 <serial port name>".
29
31 --debugger debugger_command
32 Specify a different debugger than avr-gdb (or avr-insight). This
33 other debugger should behave similarly to gdb.
34 --capture
36 Don't download the executable being debugged to the mote, just
37 interrupt the current program and assume that it matches the
38 executable passed to ice-gdb. This is similar to "attaching" to
39 a running program within gdb.
40 --ignore-intr
42 Pass the --ignore-intr option to avarice. The single-step com‐
43 mands in gdb (s, n) will then "step over" interrupt handlers
44 (i.e., if an interrupt occurs, execution will resume for the
45 duration of the interrupt).
46 --external
48 Do not start avarice. Instead, avr-gdb will attempt to connect
49 to an already running avarice on port localhost:6423.
50
52 ice-restart
53 Restart avarice.
54 ice-load filename
56 Download executable filename to the Atmel processor and start
57 debugging it (this replaces the gdb load command).
58 target-ice
60 Connect to a copy of avarice running on port localhost:6423.
61
63 The JTAG ICE debugging environment has a few restrictions and changes:
64 · No "soft" breakpoints, and only three hardware breakpoints. The
66 break command sets hardware breakpoints. The easiest way to deal
67 with this restriction is to enable and disable breakpoints as
68 needed.
69 · Two 1-byte hardware watchpoints (but each hardware watchpoint takes
71 away one hardware breakpoint). If you set a watchpoint on a vari‐
72 able which takes more than one byte, execution will be abysmally
73 slow. Instead it is better to do the following:
74 watch *(char *)&myvariable
76 which watches the least significant byte of myvariable.
78 · The Atmel AVR processors have a Harvard architecture (separate code
80 and data buses). To distinguish data address 0 from code address 0,
81 avr-gdb adds 0x800000 to all data addresses. Bear this in mind when
82 examining printed pointers, or when passing absolute addresses to
83 gdb commands.
84
86 AVARICE_ARGS
87 Extra arguments to pass to avarice at startup.
88
90 gdb(1), insight(1).
91
93 On Windows, the ice-gdb and ice-insight commands only work in the cyg‐
94 win environment. They do not work with the mingw environment.
95 August 22, 2003 ice-gdb(1)