Skip to content

Add SMBus PEC byte to ec-test-lib serial transport #92

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
dymk merged 1 commit into from
May 20, 2026
Merged

Add SMBus PEC byte to ec-test-lib serial transport #92

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions ec/Cargo.lock
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

1 change: 1 addition & 0 deletions ec/test-lib/Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@ scopeguard = { version = "1.2" }

# Serial specific
serialport = { version = "4.8.1" }
smbus-pec = "1.0.1"
embedded-services = { git = "https://github.com/OpenDevicePartnership/embedded-services", branch = "v0.2.0" }
thermal-service-messages = { git = "https://github.com/OpenDevicePartnership/embedded-services", branch = "v0.2.0" }

Expand Down
12 changes: 12 additions & 0 deletions ec/test-lib/src/serial.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -184,6 +184,8 @@ impl Serial {
.map_err(|e| Error::Io(format!("{e:?}")))?;
port.write_all(&buffer[..HEADER_SZ + request_sz])
.map_err(|e| Error::Io(format!("{e:?}")))?;
let pec = smbus_pec::pec(&buffer[..HEADER_SZ + request_sz]);
port.write_all(&[pec]).map_err(|e| Error::Io(format!("{e:?}")))?;
port.flush().map_err(|e| Error::Io(format!("{e:?}")))?;

// Read response packets
Expand All @@ -207,6 +209,16 @@ impl Serial {
.ok_or_else(|| Error::Protocol("Response does not fit in buffer".into()))?;
port.read_exact(packet_slice).map_err(|e| Error::Io(format!("{e:?}")))?;

let mut pec_buf = [0u8; 1];
port.read_exact(&mut pec_buf).map_err(|e| Error::Io(format!("{e:?}")))?;
let computed = smbus_pec::pec(&buffer[..SMBUS_HEADER_SZ + len]);
if pec_buf[0] != computed {
return Err(Error::Protocol(format!(
"PEC mismatch: received {:#04x}, computed {:#04x}",
pec_buf[0], computed
)));
}

let flags = buffer[MCTP_FLAGS_IDX];

// If this is a SOM packet, skip ODP header (we don't use it) and grab the command code/discriminant
Expand Down
Loading