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https://github.com/holub/mame
synced 2025-05-20 04:39:11 +03:00
added out of bounds check for readmem
This commit is contained in:
Michaël Banaan Ananas
parent
ad281de086
commit
a93a2948fc
@ -79,6 +79,7 @@ struct _ymz280b_state
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{
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sound_stream * stream; /* which stream are we using */
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UINT8 *region_base; /* pointer to the base of the region */
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UINT32 region_size;
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UINT8 current_register; /* currently accessible register */
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UINT8 status_register; /* current status register */
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UINT8 irq_state; /* current IRQ state */
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@ -93,7 +94,7 @@ struct _ymz280b_state
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devcb_resolved_write8 ext_ram_write; /* external RAM write handler */
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#if MAKE_WAVS
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void * wavresample; /* resampled waveform */
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void * wavresample; /* resampled waveform */
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#endif
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INT16 *scratch;
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@ -140,6 +141,20 @@ INLINE ymz280b_state *get_safe_token(device_t *device)
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}
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INLINE UINT8 ymz280b_read_memory(UINT8 *base, UINT32 size, UINT32 offset)
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{
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if (offset < size)
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return base[offset];
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/* 16MB chip limit */
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else if (offset > 0xffffff)
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return base[offset & 0xffffff];
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else
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return 0;
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}
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INLINE void update_irq_state(ymz280b_state *chip)
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{
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int irq_bits = chip->status_register & chip->irq_mask;
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@ -263,7 +278,7 @@ static void compute_tables(void)
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***********************************************************************************************/
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static int generate_adpcm(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer, int samples)
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static int generate_adpcm(struct YMZ280BVoice *voice, UINT8 *base, UINT32 size, INT16 *buffer, int samples)
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{
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int position = voice->position;
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int signal = voice->signal;
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@ -277,7 +292,7 @@ static int generate_adpcm(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer
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while (samples)
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{
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/* compute the new amplitude and update the current step */
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val = base[position / 2] >> ((~position & 1) << 2);
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val = ymz280b_read_memory(base, size, position / 2) >> ((~position & 1) << 2);
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signal += (step * diff_lookup[val & 15]) / 8;
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/* clamp to the maximum */
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@ -316,7 +331,7 @@ static int generate_adpcm(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer
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while (samples)
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{
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/* compute the new amplitude and update the current step */
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val = base[position / 2] >> ((~position & 1) << 2);
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val = ymz280b_read_memory(base, size, position / 2) >> ((~position & 1) << 2);
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signal += (step * diff_lookup[val & 15]) / 8;
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/* clamp to the maximum */
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@ -379,7 +394,7 @@ static int generate_adpcm(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer
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***********************************************************************************************/
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static int generate_pcm8(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer, int samples)
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static int generate_pcm8(struct YMZ280BVoice *voice, UINT8 *base, UINT32 size, INT16 *buffer, int samples)
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{
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int position = voice->position;
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int val;
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@ -391,7 +406,7 @@ static int generate_pcm8(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer,
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while (samples)
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{
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/* fetch the current value */
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val = base[position / 2];
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val = ymz280b_read_memory(base, size, position / 2);
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/* output to the buffer, scaling by the volume */
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*buffer++ = (INT8)val * 256;
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@ -416,7 +431,7 @@ static int generate_pcm8(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer,
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while (samples)
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{
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/* fetch the current value */
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val = base[position / 2];
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val = ymz280b_read_memory(base, size, position / 2);
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/* output to the buffer, scaling by the volume */
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*buffer++ = (INT8)val * 256;
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@ -453,7 +468,7 @@ static int generate_pcm8(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer,
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***********************************************************************************************/
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static int generate_pcm16(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer, int samples)
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static int generate_pcm16(struct YMZ280BVoice *voice, UINT8 *base, UINT32 size, INT16 *buffer, int samples)
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{
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int position = voice->position;
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int val;
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@ -465,7 +480,7 @@ static int generate_pcm16(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer
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while (samples)
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{
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/* fetch the current value */
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val = (INT16)((base[position / 2 + 1] << 8) + base[position / 2]);
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val = (INT16)((ymz280b_read_memory(base, size, position / 2 + 1) << 8) + ymz280b_read_memory(base, size, position / 2));
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/* output to the buffer, scaling by the volume */
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*buffer++ = val;
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@ -490,7 +505,7 @@ static int generate_pcm16(struct YMZ280BVoice *voice, UINT8 *base, INT16 *buffer
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while (samples)
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{
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/* fetch the current value */
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val = (INT16)((base[position / 2 + 1] << 8) + base[position / 2]);
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val = (INT16)((ymz280b_read_memory(base, size, position / 2 + 1) << 8) + ymz280b_read_memory(base, size, position / 2));
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/* output to the buffer, scaling by the volume */
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*buffer++ = val;
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@ -589,10 +604,10 @@ static STREAM_UPDATE( ymz280b_update )
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/* generate them into our buffer */
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switch (voice->playing << 7 | voice->mode)
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{
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case 0x81: samples_left = generate_adpcm(voice, chip->region_base, chip->scratch, new_samples); break;
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case 0x82: samples_left = generate_pcm8(voice, chip->region_base, chip->scratch, new_samples); break;
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case 0x83: samples_left = generate_pcm16(voice, chip->region_base, chip->scratch, new_samples); break;
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default: samples_left = 0; memset(chip->scratch, 0, new_samples * sizeof(chip->scratch[0])); break;
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case 0x81: samples_left = generate_adpcm(voice, chip->region_base, chip->region_size, chip->scratch, new_samples); break;
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case 0x82: samples_left = generate_pcm8(voice, chip->region_base, chip->region_size, chip->scratch, new_samples); break;
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case 0x83: samples_left = generate_pcm16(voice, chip->region_base, chip->region_size, chip->scratch, new_samples); break;
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default: samples_left = 0; memset(chip->scratch, 0, new_samples * sizeof(chip->scratch[0])); break;
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}
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/* if there are leftovers, ramp back to 0 */
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@ -681,6 +696,7 @@ static DEVICE_START( ymz280b )
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/* initialize the rest of the structure */
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chip->master_clock = (double)device->clock() / 384.0;
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chip->region_base = *device->region();
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chip->region_size = device->region()->bytes();
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chip->irq_callback = intf->irq_callback;
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/* create the stream */
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@ -964,7 +980,9 @@ static int compute_status(ymz280b_state *chip)
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/* ROM/RAM readback? */
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if (chip->current_register == 0x86)
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{
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return chip->region_base[chip->rom_readback_addr];
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result = ymz280b_read_memory(chip->region_base, chip->region_size, chip->rom_readback_addr);
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chip->rom_readback_addr = (chip->rom_readback_addr + 1) & 0xffffff;
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return result;
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}
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/* force an update */
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@ -994,9 +1012,14 @@ READ8_DEVICE_HANDLER( ymz280b_r )
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if ((offset & 1) == 0)
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{
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/* read from external memory */
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UINT8 read = chip->ext_ram_read.isnull() ? 0 : chip->ext_ram_read(chip->rom_readback_addr);
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UINT8 result;
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if (chip->ext_ram_read.isnull())
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result = chip->ext_ram_read(chip->rom_readback_addr);
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else
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result = ymz280b_read_memory(chip->region_base, chip->region_size, chip->rom_readback_addr);
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chip->rom_readback_addr = (chip->rom_readback_addr + 1) & 0xffffff;
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return read;
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return result;
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}
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else
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return compute_status(chip);
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