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view src/output.c @ 22:b704f7ffc8ba
Added reading of input file for pass1
author | lost |
---|---|
date | Fri, 02 Jan 2009 00:43:19 +0000 |
parents | 34568fab6058 |
children | b962cee20bf4 |
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/* output.c Copyright © 2008 William Astle This file is part of LWASM. LWASM is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. Contains the code for actually outputting the assembled code */ //#include <ctype.h> #include <errno.h> #include <stdio.h> //#include <stdlib.h> #include <string.h> #include <unistd.h> #define __output_c_seen__ //#include "instab.h" #include "lwasm.h" void write_code_raw(asmstate_t *as, FILE *of); void write_code_decb(asmstate_t *as, FILE *of); void write_code_rawrel(asmstate_t *as, FILE *of); void write_code(asmstate_t *as) { FILE *of; if (as -> errorcount > 0) { fprintf(stderr, "Not doing output due to assembly errors.\n"); return; } of = fopen(as -> outfile, "wb"); if (!of) { fprintf(stderr, "Cannot open '%s' for output", as -> outfile); perror(""); return; } switch (as -> outformat) { case OUTPUT_RAW: write_code_raw(as, of); break; case OUTPUT_DECB: write_code_decb(as, of); break; case OUTPUT_RAWREL: write_code_rawrel(as, of); break; default: fprintf(stderr, "BUG: unrecognized output format when generating output file\n"); fclose(of); unlink(as -> outfile); return; } fclose(of); } /* rawrel output treats an ORG directive as an offset from the start of the file. Undefined results will occur if an ORG directive moves the output pointer backward. This particular implementation uses "fseek" to handle ORG requests and to skip over RMBs. This simple brain damanged method simply does an fseek before outputting each instruction. */ void write_code_rawrel(asmstate_t *as, FILE *of) { sourceline_t *cl; for (cl = as -> source_head; cl; cl = cl -> next) { if (cl -> nocode) continue; fseek(of, cl -> addr, SEEK_SET); fwrite(cl -> codebytes, cl -> numcodebytes, 1, of); } } /* raw merely writes all the bytes directly to the file as is. ORG is just a reference for the assembler to handle absolute references. Multiple ORG statements will produce mostly useless results */ void write_code_raw(asmstate_t *as, FILE *of) { sourceline_t *cl; for (cl = as -> source_head; cl; cl = cl -> next) { if (cl -> nocode && cl -> len > 0) { int i; for (i = 0; i < cl -> len; i++) fwrite("\0", 1, 1, of); continue; } if (cl -> nocode) continue; fwrite(cl -> codebytes, cl -> numcodebytes, 1, of); } } void write_code_decb(asmstate_t *as, FILE *of) { long preambloc; sourceline_t *cl; int blocklen = -1; int nextcalc = -1; unsigned char outbuf[5]; for (cl = as -> source_head; cl; cl = cl -> next) { if (cl -> nocode) continue; if (cl -> addr != nextcalc && cl -> numcodebytes > 0) { // need preamble here if (blocklen > 0) { fseek(of, preambloc, SEEK_SET); outbuf[0] = (blocklen >> 8) & 0xFF; outbuf[1] = blocklen & 0xFF; fwrite(outbuf, 2, 1, of); fseek(of, 0, SEEK_END); } blocklen = 0; nextcalc = cl -> addr; outbuf[0] = 0x00; outbuf[1] = 0x00; outbuf[2] = 0x00; outbuf[3] = (nextcalc >> 8) & 0xFF; outbuf[4] = nextcalc & 0xFF; preambloc = ftell(of) + 1; fwrite(outbuf, 5, 1, of); } nextcalc += cl -> numcodebytes; fwrite(cl -> codebytes, cl -> numcodebytes, 1, of); blocklen += cl -> numcodebytes; } if (blocklen > 0) { fseek(of, preambloc, SEEK_SET); outbuf[0] = (blocklen >> 8) & 0xFF; outbuf[1] = blocklen & 0xFF; fwrite(outbuf, 2, 1, of); fseek(of, 0, SEEK_END); } // now write postamble outbuf[0] = 0xFF; outbuf[1] = 0x00; outbuf[2] = 0x00; outbuf[3] = (as -> execaddr >> 8) & 0xFF; outbuf[4] = (as -> execaddr) & 0xFF; fwrite(outbuf, 5, 1, of); }