| Getting Started with M1750 Ada: Ada 95 Compilation System for Spacecraft Microprocessors | ||
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Before we can make full use of the debugger, we must recompile hello.adb using the debug option. This option tells the compiler to include information about the source code, and the mapping of source code to generated code. Then the debugger can operate at source code level rather than at machine code level.
The debug information does not alter the generated code in any way but it does make object code files much bigger. Normally this is not a problem, but if you wish to remove the debug information from a file, then use the object code utility m1750-coff-strip.
This is how we recompile hello.adb with the -g option. There are other debug options too. See the M1750 Ada User's Guide for more information on debug options.
bash$ m1750-coff-gnatmake -f -g hello m1750-coff-gcc -c -g hello.adb m1750-coff-gnatbind -x hello.ali m1750-coff-gnatlink -g hello.ali
The debugger is m1750-coff-gdb. By default the debugger will run a M1750 program on the M1750 simulator. If you prefer to run and debug on a real M1750 then you must arrange for your target to communicate with the host using the debugger's remote debug protocol. This is described in Section 2.7.
Example 2-5. Running under the Debugger
$ m1750-coff-gdb hello
XGC m1750-ada Version 1.7 (debugger)
Copyright (c) 1996, 2001, XGC Software.
Based on gdb version 4.17.gnat.3.11
Copyright (c) 1998 Free Software Foundation...
(gdb)break main
Breakpoint 1 at 0x408: file b~hello.adb, line 29.
(gdb)run
Starting program: /home/nettleto/xgc/m1750-ada/examples/hello
Connected to the simulator.
Loading sections:
Idx Name Size VMA LMA File off Algn
0 .init 000003fa 00000000 00000000 00001000 2**1
CONTENTS, ALLOC, LOAD, CODE
1 .text 000005e6 000003fa 000003fa 000013fa 2**1
CONTENTS, ALLOC, LOAD, CODE
2 .rdata 0000006c 000009e0 000009e0 000019e0 2**1
CONTENTS, ALLOC, LOAD, READONLY
3 .data 000000d4 00010000 00000a4c 00002000 2**1
CONTENTS, ALLOC, LOAD, DATA
Start address 0x0
Transfer rate: 22784 bits in <1 sec.
Breakpoint 1, main () at b~hello.adb:29
29 adainit;
(gdb)continue
Continuing.
Hello World
Program exited normally.
(gdb)quit
You can view the debug information using the object dump utility, as follows:
Example 2-6. Dump of Debug Information
bash$ m1750-coff-objdump -G hello hello: file format coff-m1750 Contents of .stab section: Symnum n_type n_othr n_desc n_value n_strx String -1 HdrSym 0 700 00001508 1 0 SO 0 0 00000438 14 /home/opt/m1750-ada-1.7/m1750-coff/src/libada/rts/ 1 SO 0 0 00000438 1 x-textio.adb 2 LSYM 0 0 00000000 66 long int:t1=r1;-32768;32767; 3 LSYM 0 0 00000000 95 unsigned char:t2=r2;0;65535; 4 LSYM 0 0 00000000 124 long integer:t3=r1;0020000000000;0017777777777; ...