* @(#)reloc.mac 1.7 * By Peter S. Gilmour, Motorola Development Systems, Austin, TX * * This file contains items useful for debugging code assembled in * several relocatable modules and then linked into one object file. * It also contains some hints and serves as an example of what macro * operations can do. * * The problem with debugging a relocatable module is that the assembly * listing shows module relative addresses and the code will execute at * address $XXXX while it's data will be at $DDDD. To overcome this * problem, the following named macros and local symbols make life bearable * again. * * Local symbol definitions: * X = base address of relocatable module being debugged. * D = base address of initialized data section. * B = base address of uninitialized data section. * W = "where am i"; just type "'W" to calculate the current PC * offset from the base address of the module. This is a local * symbol "command". * START = starting execution address of program. * FDC = "floppy disk controller register display"; just type "'FDC" to * do a memory display of the controller register values. This is * a local symbol "command". * PIA1 = "PIA 1 register display"; just type "'PIA" to do a memory * display of the PIA 1 register values. This is a local symbol * "command". * TBL = "table display"; just type "'TBL" to do a memory display of * table values. This is a local symbol "command". * * Named Macros: * T = new single step trace cmd with register display and PC * disassembly. * U = trace until
is reached cmd. Deletes BR at current * PC, sets BR at
entered, and issues G cmd. * BU = set BR at current PC and does U named macro. * L = list (disassemble) 5 lines from the current PC. * TT = old single step trace cmd. * TW4 = trace thru a 4 byte subroutine call (sets brkpt at .PC+4). * TW8 = trace thru an 8 byte subroutine call (sets brkpt at .PC+8). * MODULE1 = set up for Module 1 debug and patches. * MODULE2 = set up for Module 2 debug and patches. * WAITDONE = wait until Status is no longer "RUNNING". * XADD = adds parameter 1 to local symbol X (module base) * XSUB = subtracts parameter 1 from local symbol X (module base) * SUBX = subtracts local symbol X (module base) from parameter 1 * CYCLE = alternately stores parameter 2 and parameter 3 at the * location specified by parameter 1 until the abort character * is entered (^A). * * Sample debug session: * LOAD MYPROG Load saved copy of program. * MODULE2 Setup for debugging module 2. * G 'START Start program. Stops at preset breakpoint. * BR 'X+2ed Set new breakpoint at module address $2ED. * G Execute to breakpoint. * T ,20 Trace 20 decimal instructions, then display regs. * 'W Display relative PC (where am i) * 'FDC Display FDC registers. * 'PIA1 Display PIA 1 registers. * 'TBL Display table contents. * T Trace 1 instruction, then display regs. * TW4 Trace thru 4 byte subr. call. * MD 'B+32,4 Display memory in base section. * BR 'X+35e Set new breakpoint at module address $35E. * G Execute to breakpoint. * NOBR .PC Delete this breakpoint. * NOBR 'X+2ed Delete old breakpoint. * L List 5 disassembled lines from current PC. * G Execute to breakpoint. * U 'X+4ac Execute from this breakpoint until new breakpoint. * T ,3 Trace 3 instructions, then display regs. * BU 'X+4dc Set BP at PC, then go until new breakpoint. * * etc. * * Hints: * 1. You can use the current value of any register in expressions for any * HDS-300 command as shown below. Consult the help system for the * calculate command (HELP C) for more details on allowable expressions * for your pod. * * a. Set or delete breakpoints using the program counter as follows; * BR .PC Set brkpt at current PC. * BR .PC+4 Set brkpt at current PC+4. * NOBR .PC Delete brkpt at current PC. * * b. Display memory via register values as follows; * MD .A0,40 Display $40 bytes at location in A0. * MD [.A0],40 Display $40 bytes at location indirectly * referenced in A0. * * Notes: * 1. This macro was set up for HDS-300/68008 operation. There may be * some changes required if used on a different system, i.e. the * 68020 has to have double quotes around the command text entered * for BR commands. * Ex: @br .pc+4 rd for 68008 * @br .pc+4 "rd" for 68020 * * References: * 1. "HDS-300 Hardware Development Station Operations Manual" for your * pod, under "The Macro Utility" section. * * You may delete all the above comments from your working version copy * or modify this file to suite your particular needs. T @t \0 @rd @dasm .pc,1 U @nobr .pc @br \0 DB @g BU @br .pc U \0 L @dasm .pc,5 DB @rd @dasm .pc,1 TT @t \0 TW4 @br .pc+4 @rd @g @whilel 0 "RUNNING" @end @nobr .pc @dasm .pc,1 'w TW8 @br .pc+8 @rd @g @whilel 0 "RUNNING" @end @nobr .pc @dasm .pc,1 'w *** * Common symbols for all modules COMSYMB @ls start 1000 @ls w C .PC-'X @ls fdc md fe78,4 @ls pia1 md fea0,2 MODULE1 ** Setup for 01/27/88 assembly version of Module 1 ** @ls x 24b9 @ls d 47ce @ls b 3e * Table is 39 entries of 2 bytes each! @ls tbl md 'd+34,&39*2 ;wd COMSYMB *** no patches at this time *** * Set breakpoints. @nobr @br 'x @rd @br 'x+e @rd MODULE2 ** Setup for 01/29/88 assembly version of Module 2 ** @ls x 24b9 @ls d 47ce @ls b 3e * Table is 47 entries of 2 bytes each! @ls tbl md 'd+4b,&47*2 ;wd COMSYMB @asm 'x+2a9 nop;q @ms 'd+10c 4 21 39 * Set breakpoints. @nobr @br 'x @rd @br 'x+e @rd WAITDONE @whilel 0 "RUNNING" @end XADD @c 'x+\0 XSUB @c 'x-\0 SUBX @c \0-'x CYCLE @repeat @ms \0 \1 @wait 10 @ms \0 \2 @wait 10 @end **EOF**