spc700dis.c

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// SPDX-FileCopyrightText: 2014 condret <condr3t@protonmail.com>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_types.h>
#include <rz_asm.h>
#include <stdio.h>
#include <string.h>
#include "spc700_opcode_table.h"
 
static ut64 spc700_op_size(Spc700ArgType arg) {
    switch (arg) {
    case SPC700_ARG_NONE:
        return 1;
    case SPC700_ARG_IMM8:
    case SPC700_ARG_ABS8:
    case SPC700_ARG_REL8:
    case SPC700_ARG_UPPER8:
        return 2;
    case SPC700_ARG_ABS8_REL8:
    case SPC700_ARG_ABS8_ABS8:
    case SPC700_ARG_ABS16:
    case SPC700_ARG_ABS13_BIT3:
    case SPC700_ARG_IMM8_ABS8:
        return 3;
    }
    return 0;
}
 
static ut64 spc700_resolve_relative(ut64 pc, ut8 r) {
    ut16 spc = (ut16)pc;
    ut16 relpc = (ut16)(st16)(st8)r;
    spc += relpc;
    return (ut64)spc;
}
 
static size_t spc700_disas(RzStrBuf *out, ut64 pc, const ut8 *buf, size_t bufsz) {
    if (!bufsz) {
        return 0;
    }
    const Spc700Op *sop = &spc700_op_table[buf[0]];
    ut64 opsz = spc700_op_size(sop->arg);
    if (bufsz < (ut64)opsz) {
        return 0;
    }
    if (!out) {
        return opsz;
    }
    switch (sop->arg) {
    case SPC700_ARG_NONE:
        rz_strbuf_set(out, sop->name);
        break;
    case SPC700_ARG_IMM8:
    case SPC700_ARG_ABS8:
    case SPC700_ARG_UPPER8:
        rz_strbuf_setf(out, sop->name, (unsigned int)buf[1]);
        break;
    case SPC700_ARG_ABS8_REL8:
        rz_strbuf_setf(out, sop->name,
            (unsigned int)buf[1],
            (unsigned int)spc700_resolve_relative(pc + 3, buf[2]));
        break;
    case SPC700_ARG_ABS16:
        rz_strbuf_setf(out, sop->name, (unsigned int)buf[1] | ((unsigned int)buf[2] << 8));
        break;
    case SPC700_ARG_ABS13_BIT3:
        rz_strbuf_setf(out, sop->name,
            (unsigned int)((ut16)buf[1] | ((ut16)(buf[2] & 0x1f) << 8)),
            (unsigned int)(buf[2] >> 5));
        break;
    case SPC700_ARG_REL8:
        rz_strbuf_setf(out, sop->name,
            (unsigned int)spc700_resolve_relative(pc + 2, buf[1]));
        break;
    case SPC700_ARG_IMM8_ABS8:
    case SPC700_ARG_ABS8_ABS8:
        rz_strbuf_setf(out, sop->name, (unsigned int)buf[2], (unsigned int)buf[1]);
        break;
    default:
        rz_strbuf_set(out, "invalid");
        break;
    }
    return opsz;
}