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view lwasm/os9.c @ 473:8181ddd707f1
Add "nooutput" pragma
Add the "nooutput" pragma which causes assembly to proceed as normal for
code with the exception that no output is generated for any instructions
under this pragma. The current address is increased as usual and the symbol
table is still constructed. However, no actual output is generated for lines
operating under this pragma.
author | William Astle <lost@l-w.ca> |
---|---|
date | Thu, 01 Nov 2018 23:07:03 -0600 |
parents | 8764142b3192 |
children | 928c033c0cd0 |
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/* os9.c Copyright © 2009 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/>. This file implements the various pseudo operations related to OS9 target */ #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <lw_expr.h> #include "lwasm.h" #include "instab.h" // OS9 syscall PARSEFUNC(pseudo_parse_os9) { lw_expr_t e; if (as -> output_format != OUTPUT_OS9 && as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_DIRECTIVE_OS9_ONLY, "%s", "os9"); return; } // fetch immediate value e = lwasm_parse_expr(as, p); if (!e) { lwasm_register_error(as, l, E_OPERAND_BAD); return; } lwasm_save_expr(l, 0, e); l -> len = 3; } EMITFUNC(pseudo_emit_os9) { lw_expr_t e; e = lwasm_fetch_expr(l, 0); lwasm_emitop(l, 0x103f); lwasm_emitexpr(l, e, 1); } PARSEFUNC(pseudo_parse_mod) { lw_expr_t e; int i; if (as -> output_format != OUTPUT_OS9) { lwasm_register_error2(as, l, E_DIRECTIVE_OS9_ONLY, "%s", "mod"); skip_operand(p); return; } if (as -> inmod) { lwasm_register_error(as, l, E_MODULE_IN); skip_operand(p); return; } // parse 6 expressions... for (i = 0; i < 5; i++) { e = lwasm_parse_expr(as, p); if (!e) { lwasm_register_error(as, l, E_OPERAND_BAD); return; } lwasm_save_expr(l, i, e); if (**p != ',') { lwasm_register_error(as, l, E_OPERAND_BAD); return; } (*p)++; } e = lwasm_parse_expr(as, p); if (!e) { lwasm_register_error(as, l, E_OPERAND_BAD); return; } lwasm_save_expr(l, 5, e); l -> inmod = 1; // we have an implicit ORG 0 with "mod" lw_expr_destroy(l -> addr); l -> addr = lw_expr_build(lw_expr_type_int, 0); // likewise for data pointer lw_expr_destroy(l -> daddr); l -> daddr = lw_expr_build(lw_expr_type_int, 0); // init crc as -> inmod = 1; l -> len = 13; } EMITFUNC(pseudo_emit_mod) { lw_expr_t e1, e2, e3, e4; int csum; as -> crc[0] = 0xff; as -> crc[1] = 0xff; as -> crc[2] = 0xff; // sync bytes lwasm_emit(l, 0x87); lwasm_emit(l, 0xcd); // mod length lwasm_emitexpr(l, e1 = lwasm_fetch_expr(l, 0), 2); // name offset lwasm_emitexpr(l, e2 = lwasm_fetch_expr(l, 1), 2); // type lwasm_emitexpr(l, e3 = lwasm_fetch_expr(l, 2), 1); // flags/rev lwasm_emitexpr(l, e4 = lwasm_fetch_expr(l, 3), 1); // header check csum = ~(0x87 ^ 0xCD ^(lw_expr_intval(e1) >> 8) ^ (lw_expr_intval(e1) & 0xff) ^ (lw_expr_intval(e2) >> 8) ^ (lw_expr_intval(e2) & 0xff) ^ lw_expr_intval(e3) ^ lw_expr_intval(e4)); lwasm_emit(l, csum); // module type specific output // note that these are handled the same for all so // there need not be any special casing // exec offset or fmgr name offset lwasm_emitexpr(l, lwasm_fetch_expr(l, 4), 2); // data size or drvr name offset lwasm_emitexpr(l, lwasm_fetch_expr(l, 5), 2); } PARSEFUNC(pseudo_parse_emod) { skip_operand(p); if (as -> output_format != OUTPUT_OS9) { lwasm_register_error2(as, l, E_DIRECTIVE_OS9_ONLY, "%s", "emod"); return; } if (!(as -> inmod)) { lwasm_register_error(as, l, E_MODULE_NOTIN); return; } as -> inmod = 0; l -> len = 3; } EMITFUNC(pseudo_emit_emod) { unsigned char tcrc[3]; // don't mess with CRC! tcrc[0] = as -> crc[0] ^ 0xff; tcrc[1] = as -> crc[1] ^ 0xff; tcrc[2] = as -> crc[2] ^ 0xff; lwasm_emit(l, tcrc[0]); lwasm_emit(l, tcrc[1]); lwasm_emit(l, tcrc[2]); }