exmemwb_misc.c

#include "decode.h"
#include "exmemwb.h"
#include <stdlib.h>

u32 breakpoint(void) { return 0; }

/*
int handle_bkpt(unsigned int bp, unsigned int arg)
{
        int r = 1;
        FILE *f;
        int s, e, n;
        unsigned int sp;

        sp = read_register(13);
        switch (arg) {
                case 0x18:
                        fprintf(stderr, "Exiting.\n");
                        break;
                case 0x80:
                        s = read32(sp + 8);
                        e = read32(sp + 4);
                        fprintf(stderr, "Dumping from %08X to %08X...\n",
                                        s, e);
                        f = fopen(output_file_name, "wb");
                        while (s != e) {
                                n = read32(s);
                                fwrite(&n, 4, 1, f);
                                s += 4;
                        }
                        fclose(f);
                        write_register(13, sp + 12);
                        r = 0;
                        break;
                default:
                        fprintf(stderr, "bkpt 0x%02X %08X\n", bp, arg);
                        break;
        }
        return r;
}*/

///--- Move operations -------------------------------------------///

// MOVS - write an immediate to the destination register
u32 movs_i() {
  diss_printf("movs r%u, #0x%02X\n", decoded.rD, decoded.imm);

  u32 opA = zeroExtend32(decoded.imm);
  cpu_set_gpr(decoded.rD, opA);

  do_nflag(opA);
  do_zflag(opA);

  return 1;
}

// MOV - copy the source register value to the destination register
u32 mov_r() {
  diss_printf("mov r%u, r%u\n", decoded.rD, decoded.rM);

  u32 opA = cpu_get_gpr(decoded.rM);

  if (decoded.rD == GPR_PC)
    alu_write_pc(opA);
  else
    cpu_set_gpr(decoded.rD, opA);

  return 1;
}

// MOVS - copy the low source register value to the destination low register
u32 movs_r() {
  diss_printf("movs r%u, r%u\n", decoded.rD, decoded.rM);

  u32 opA = cpu_get_gpr(decoded.rM);
  cpu_set_gpr(decoded.rD, opA);

  do_nflag(opA);
  do_zflag(opA);

  return 1;
}

///--- Bit twiddling operations -------------------------------------------///

// SXTB - Sign extend a byte to a word
u32 sxtb() {
  diss_printf("sxtb r%u, r%u\n", decoded.rD, decoded.rM);

  u32 result = 0xFF & cpu_get_gpr(decoded.rM);
  result = (result & 0x80) != 0 ? (result | 0xFFFFFF00) : result;

  cpu_set_gpr(decoded.rD, result);

  return 1;
}

// SXTH - Sign extend a halfword to a word
u32 sxth() {
  diss_printf("sxth r%u, r%u\n", decoded.rD, decoded.rM);

  u32 result = 0xFFFF & cpu_get_gpr(decoded.rM);
  result = (result & 0x8000) != 0 ? (result | 0xFFFF0000) : result;

  cpu_set_gpr(decoded.rD, result);

  return 1;
}

// UXTB - Extend a byte to a word
u32 uxtb() {
  diss_printf("uxtb r%u, r%u\n", decoded.rD, decoded.rM);

  u32 result = 0xFF & cpu_get_gpr(decoded.rM);
  cpu_set_gpr(decoded.rD, result);

  return 1;
}

// UXTH - Extend a halfword to a word
u32 uxth() {
  diss_printf("uxth r%u, r%u\n", decoded.rD, decoded.rM);

  u32 result = 0xFFFF & cpu_get_gpr(decoded.rM);
  cpu_set_gpr(decoded.rD, result);

  return 1;
}

// REV - Reverse ordering of bytes in a word
u32 rev() {
  diss_printf("rev r%u, r%u\n", decoded.rD, decoded.rM);

  u32 opA = cpu_get_gpr(decoded.rM);
  u32 result = opA << 24;
  result |= (opA << 8) & 0xFF0000;
  result |= (opA >> 8) & 0xFF00;
  result |= (opA >> 24);

  cpu_set_gpr(decoded.rD, result);

  return 1;
}

// REV16 - Reverse ordering of bytes in a packed halfword
u32 rev16() {
  diss_printf("rev16 r%u, r%u\n", decoded.rD, decoded.rM);

  u32 opA = cpu_get_gpr(decoded.rM);
  u32 result = (opA << 8) & 0xFF000000;
  result |= (opA >> 8) & 0xFF0000;
  result |= (opA << 8) & 0xFF00;
  result |= (opA >> 8) & 0xFF;

  cpu_set_gpr(decoded.rD, result);

  return 1;
}

// REVSH - Reverse ordering of bytes in a signed halfword
u32 revsh() {
  diss_printf("revsh r%u, r%u\n", decoded.rD, decoded.rM);

  u32 opA = cpu_get_gpr(decoded.rM);
  u32 result = (opA & 0x8) != 0 ? (0xFFFFFF00 | opA) : (0xFF & opA);
  result <<= 8;
  result |= (opA >> 8) & 0xFF;

  cpu_set_gpr(decoded.rD, result);

  return 1;
}