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Fix Si4684 DAB response-parsing bugs found in firmware review

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readDabServiceData(): 6 of 7 response fields (dataSrc, serviceId,
componentId, byteCount, segmentIndex, segmentCount) read one byte too
early, using the old raw[4]=RESP4 convention instead of the correct
raw[5]=RESP4 (established elsewhere in this driver by getPartInfo() and
readDabDigRadStatus()'s own ficQuality/cnrDb fields). dataSrc landing on
the wrong byte meant the DAB dynamic label (PAD/now-playing text) check
(dataSrc == 2) could essentially never match — it has likely never worked.
Header buffer grown 24->25 bytes to fit the correctly-positioned last field.

fetchDabServiceList(): didn't match AN649 Table 14's "DAB/DMB Digital
Service List" layout at all — serviceCount read from the wrong byte, every
per-service field misaligned, componentId assumed 4 bytes wide (actually
2 per the spec), and only the first of a service's possibly-several
components was ever skipped past (desyncing every later entry). Rewrote
against the actual Table 14 field layout. Confirmed live yesterday this
was producing garbled service_id/component_id/label output
(component_id values decoding as literal ASCII spaces).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0178rASQ6ZETPMUamvpoR2KR
This commit is contained in:
michele
2026-08-18 07:50:09 +02:00
co-authored by Claude Sonnet 5
parent 9b337e7bca
commit 8a69cbed08
2 changed files with 54 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Software/components/drivers/si4684/src/Si4684Driver.cpp
+37 -24
View File
@@ -962,7 +962,12 @@ Si4684Driver::readDabServiceData(bool statusOnly, bool ack)
return std::unexpected(Si4684Error::CommandFailed);
}
std::array<std::uint8_t, 24> header = {};
// raw[5]=RESP4 (see readFmRds()). AN649 Command 0x84 response:
// RESP4=flags, RESP5=BUFF_COUNT, RESP6=SRV_STATE, RESP7=DATA_SRC/DSCTy,
// RESP8-11=SERVICE_ID, RESP12-15=COMP_ID, RESP16-17=UATYPE,
// RESP18-19=BYTE_COUNT, RESP20-21=SEG_NUM, RESP22-23=NUM_SEGS — 25
// header bytes total (lead-in + STATUS0-3 + RESP4-23).
std::array<std::uint8_t, 25> header = {};
if (auto rd = readRaw(header); !rd) {
return std::unexpected(rd.error());
}
@@ -973,11 +978,11 @@ Si4684Driver::readDabServiceData(bool statusOnly, bool ack)
}
}
const std::uint16_t byteCount = readLe16(header.data() + 18);
const std::uint16_t byteCount = readLe16(header.data() + 19);
if (byteCount == 0U) {
return std::optional<Si4684DabServiceData>{};
}
if (byteCount + 24U > kSpiBufferSize) {
if (byteCount + 25U > kSpiBufferSize) {
return std::unexpected(Si4684Error::ReplyTooShort);
}
@@ -989,12 +994,12 @@ Si4684Driver::readDabServiceData(bool statusOnly, bool ack)
}
Si4684DabServiceData data = {};
data.dataSrc = static_cast<std::uint8_t>((header[7] >> 6U) & 0x03U);
data.serviceId = readLe32(header.data() + 8);
data.componentId = readLe32(header.data() + 12);
data.dataSrc = static_cast<std::uint8_t>((header[8] >> 6U) & 0x03U);
data.serviceId = readLe32(header.data() + 9);
data.componentId = readLe32(header.data() + 13);
data.byteCount = byteCount;
data.segmentIndex = readLe16(header.data() + 20);
data.segmentCount = readLe16(header.data() + 22);
data.segmentIndex = readLe16(header.data() + 21);
data.segmentCount = readLe16(header.data() + 23);
data.payload = std::move(body);
return data;
}
@@ -1115,42 +1120,50 @@ Si4684Driver::fetchDabServiceList()
return std::unexpected(rd.error());
}
// raw[5]=RESP4=SIZE[7:0], raw[6]=RESP5=SIZE[15:8] (see readFmRds()).
const std::uint16_t payloadSize = readLe16(header.data() + 5);
if (payloadSize == 0U || payloadSize + 6U > kSpiBufferSize) {
if (payloadSize == 0U || payloadSize + 7U > kSpiBufferSize) {
return std::unexpected(Si4684Error::ReplyTooShort);
}
std::vector<std::uint8_t> body(payloadSize + 6U, 0U);
// DATA_0 (first byte of the AN649 Table 14 "DAB/DMB Digital Service
// List" structure) is RESP6 = body[7]: lead-in(1) + STATUS0-3(4) +
// SIZE(2) = 7 header bytes before it.
std::vector<std::uint8_t> body(payloadSize + 7U, 0U);
if (auto rd = readRaw(body); !rd) {
return std::unexpected(rd.error());
}
const std::uint8_t serviceCount = body[9];
// Table 14: List Size(2) + Version(2) + NumServices(1) + AlignPad(3) =
// 8 bytes, then Service 1 begins.
const std::uint8_t serviceCount = body[11];
std::vector<Si4684DabService> services;
services.reserve(serviceCount);
std::size_t offset = 13U;
std::size_t offset = 15U;
for (std::uint8_t i = 0; i < serviceCount; ++i) {
// Fixed per-service part: ServiceID(4) + ServiceInfo1-3(3) +
// AlignPad(1) + Label(16) = 24 bytes.
if (offset + 24U > body.size()) {
break;
}
Si4684DabService entry = {};
entry.serviceId = readLe32(body.data() + offset);
offset += 4U;
entry.serviceType = body[offset] & 0x3FU;
const std::uint8_t componentCount = body[offset + 1] & 0x0FU;
offset += 4U;
std::memcpy(entry.label.data(), body.data() + offset, 16U);
entry.serviceType = body[offset + 4U];
const std::uint8_t componentCount = body[offset + 5U] & 0x0FU;
std::memcpy(entry.label.data(), body.data() + offset + 8U, 16U);
entry.label[16] = '\0';
offset += 16U;
offset += 24U;
if (componentCount > 0U && offset + 4U <= body.size()) {
entry.componentId = readLe32(body.data() + offset);
offset += 4U;
if (offset < body.size()) {
++offset;
}
// Component ID is 2 bytes (AN649 Table 14); only the first
// component's ID is exposed on this DTO. Every component (M =
// componentCount) must still be skipped to keep the next service
// entry aligned, each one ComponentID(2) + ComponentInfo(1) +
// ValidFlags(1) = 4 bytes.
if (componentCount > 0U && offset + 2U <= body.size()) {
entry.componentId = readLe16(body.data() + offset);
}
offset += static_cast<std::size_t>(componentCount) * 4U;
services.push_back(entry);
}
return services;