URL
https://opencores.org/ocsvn/eco32/eco32/trunk
Subversion Repositories eco32
[/] [eco32/] [tags/] [eco32-0.22/] [sim/] [disasm.c] - Rev 99
Go to most recent revision | Compare with Previous | Blame | View Log
/* * disasm.c -- disassembler */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "common.h" #include "console.h" #include "error.h" #include "instr.h" #include "disasm.h" static char instrBuffer[100]; static void disasmN(char *opName, Word immed) { if (immed == 0) { sprintf(instrBuffer, "%-7s", opName); } else { sprintf(instrBuffer, "%-7s %08X", opName, immed); } } static void disasmRH(char *opName, int r1, Half immed) { sprintf(instrBuffer, "%-7s $%d,%04X", opName, r1, immed); } static void disasmRHH(char *opName, int r1, Half immed) { sprintf(instrBuffer, "%-7s $%d,%08X", opName, r1, (Word) immed << 16); } static void disasmRRH(char *opName, int r1, int r2, Half immed) { sprintf(instrBuffer, "%-7s $%d,$%d,%04X", opName, r1, r2, immed); } static void disasmRRS(char *opName, int r1, int r2, Half immed) { sprintf(instrBuffer, "%-7s $%d,$%d,%s%04X", opName, r1, r2, SIGN(16) & immed ? "-" : "+", SIGN(16) & immed ? -SEXT16(immed) : SEXT16(immed)); } static void disasmRRR(char *opName, int r1, int r2, int r3) { sprintf(instrBuffer, "%-7s $%d,$%d,$%d", opName, r1, r2, r3); } static void disasmRRB(char *opName, int r1, int r2, Half offset, Word locus) { sprintf(instrBuffer, "%-7s $%d,$%d,%08X", opName, r1, r2, (locus + 4) + (SEXT16(offset) << 2)); } static void disasmJ(char *opName, Word offset, Word locus) { sprintf(instrBuffer, "%-7s %08X", opName, (locus + 4) + (SEXT26(offset) << 2)); } static void disasmJR(char *opName, int r1) { sprintf(instrBuffer, "%-7s $%d", opName, r1); } char *disasm(Word instr, Word locus) { Byte opcode; Instr *ip; opcode = (instr >> 26) & 0x3F; ip = instrCodeTbl[opcode]; if (ip == NULL) { disasmN("???", 0); } else { switch (ip->format) { case FORMAT_N: disasmN(ip->name, instr & 0x03FFFFFF); break; case FORMAT_RH: disasmRH(ip->name, (instr >> 16) & 0x1F, instr & 0x0000FFFF); break; case FORMAT_RHH: disasmRHH(ip->name, (instr >> 16) & 0x1F, instr & 0x0000FFFF); break; case FORMAT_RRH: disasmRRH(ip->name, (instr >> 16) & 0x1F, (instr >> 21) & 0x1F, instr & 0x0000FFFF); break; case FORMAT_RRS: disasmRRS(ip->name, (instr >> 16) & 0x1F, (instr >> 21) & 0x1F, instr & 0x0000FFFF); break; case FORMAT_RRR: disasmRRR(ip->name, (instr >> 11) & 0x1F, (instr >> 21) & 0x1F, (instr >> 16) & 0x1F); break; case FORMAT_RRX: if ((opcode & 1) == 0) { /* the FORMAT_RRR variant */ disasmRRR(ip->name, (instr >> 11) & 0x1F, (instr >> 21) & 0x1F, (instr >> 16) & 0x1F); } else { /* the FORMAT_RRH variant */ disasmRRH(ip->name, (instr >> 16) & 0x1F, (instr >> 21) & 0x1F, instr & 0x0000FFFF); } break; case FORMAT_RRY: if ((opcode & 1) == 0) { /* the FORMAT_RRR variant */ disasmRRR(ip->name, (instr >> 11) & 0x1F, (instr >> 21) & 0x1F, (instr >> 16) & 0x1F); } else { /* the FORMAT_RRS variant */ disasmRRS(ip->name, (instr >> 16) & 0x1F, (instr >> 21) & 0x1F, instr & 0x0000FFFF); } break; case FORMAT_RRB: disasmRRB(ip->name, (instr >> 21) & 0x1F, (instr >> 16) & 0x1F, instr & 0x0000FFFF, locus); break; case FORMAT_J: disasmJ(ip->name, instr & 0x03FFFFFF, locus); break; case FORMAT_JR: disasmJR(ip->name, (instr >> 21) & 0x1F); break; default: error("illegal entry in instruction table"); } } return instrBuffer; }
Go to most recent revision | Compare with Previous | Blame | View Log