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hfe: Process HFEv3 opcodes when writing

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Eric Anderson 2023-07-16 10:59:11 -07:00 committed by Keir Fraser
parent 959fd9a4a0
commit 69e2c545a3
1 changed files with 63 additions and 3 deletions
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66
src/image/hfe.c
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@ -179,6 +179,13 @@ static void hfe_setup_track(
} else {
/* Write mode. */
im->hfe.trk_pos = im->cur_bc / 8;
if (im->hfe.is_v3) {
/* Provide context to the write to avoid corrupting an opcode. */
if ((im->hfe.trk_pos & 255) == 0 && im->hfe.trk_pos != 0)
im->hfe.trk_pos--;
else if ((im->hfe.trk_pos & 255) == 1)
im->hfe.trk_pos = (im->hfe.trk_pos+1) % im->hfe.trk_len;
}
im->hfe.write.start = im->hfe.trk_pos;
im->hfe.write.wrapped = FALSE;
im->hfe.write_batch.len = 0;
@ -273,6 +280,7 @@ static uint16_t hfe_rdata_flux(struct image *im, uint16_t *tbuf, uint16_t nr)
x = _rbit32(bc_b[(bc_c/8) & bc_mask]) >> 24;
im->ticks_per_cell = ticks_per_cell =
(sampleclk_us(2) * 16 * x) / 72;
im->write_bc_ticks = ticks_per_cell / 16;
bc_c += 8;
im->cur_bc += 8;
continue;
@ -333,6 +341,7 @@ static bool_t hfe_write_track(struct image *im)
unsigned int bufmask = wr->len - 1;
uint8_t *w, *wrbuf = im->bufs.write_data.p;
uint32_t i, space, c = wr->cons / 8, p = wr->prod / 8;
bool_t is_v3 = im->hfe.is_v3;
bool_t writeback = FALSE;
time_t t;
@ -384,11 +393,62 @@ static bool_t hfe_write_track(struct image *im)
+ (im->cur_track & 1) * 256
+ batch_off - im->hfe.write_batch.off
+ (off & 255);
for (i = 0; i < nr; i++)
*w++ = _rbit32(buf[c++ & bufmask]) >> 24;
i = 0;
if (is_v3 && off == im->hfe.write.start && off != 0) {
/* Avoid starting write in the middle of an opcode. */
if (w[-2] == OP_SkipBits) {
i++;
} else {
switch (w[-1]) {
case OP_SkipBits:
i += 2;
break;
case OP_Bitrate:
i++;
break;
default:
break;
}
}
}
while (i < nr) {
if (is_v3 && (w[i] & 0xf) == 0xf) {
switch (w[i]) {
case OP_SkipBits:
/* Keep the write byte-aligned. This changes the length of
* the track by 8+skip bitcells, but overwriting OP_SkipBits
* should be rare. */
w[i++] = OP_Nop;
continue;
case OP_Bitrate:
/* Assume bitrate does not change significantly for the
* entire track, and write_bc_ticks already adjusted when
* reading. */
i += 2;
continue;
case OP_Nop:
case OP_Index:
default:
/* Preserve opcode. But making sure not to write past end of
* buffer. */
i++;
continue;
case OP_Rand:
/* Replace with data. */
break;
}
}
w[i++] = _rbit32(buf[c++ & bufmask]) >> 24;
}
im->hfe.write_batch.dirty = TRUE;
im->hfe.trk_pos += nr;
im->hfe.trk_pos += i; /* i may be larger than nr due to opcodes. */
if (im->hfe.trk_pos >= im->hfe.trk_len) {
ASSERT(im->hfe.trk_pos == im->hfe.trk_len);
im->hfe.trk_pos = 0;