58 lines
1.7 KiB
Markdown
58 lines
1.7 KiB
Markdown
# Flashing Sequence (ECU Programming)
|
|
|
|
This document outlines the expected flashing workflow using the `HexFlasher` scaffold over the LIN interface and where you can plug in your production flasher (UDS/XCP).
|
|
|
|
## Overview
|
|
|
|
- Flashing is controlled by configuration (`flash.enabled`, `flash.hex_path`)
|
|
- The `flash_ecu` session fixture invokes the flasher before tests
|
|
- The flasher uses the same `LinInterface` as tests
|
|
|
|
## Mermaid sequence
|
|
|
|
```mermaid
|
|
sequenceDiagram
|
|
autonumber
|
|
participant P as pytest
|
|
participant F as flash_ecu fixture
|
|
participant H as HexFlasher
|
|
participant L as LinInterface (mock/babylin)
|
|
participant E as ECU
|
|
|
|
P->>F: Evaluate flashing precondition
|
|
alt flash.enabled == true and hex_path provided
|
|
F->>H: HexFlasher(lin).flash_hex(hex_path)
|
|
H->>L: connect (ensure session ready)
|
|
H->>E: Enter programming session (UDS/XCP)
|
|
H->>E: Erase memory (as required)
|
|
loop For each block in HEX
|
|
H->>L: Transfer block via LIN frames
|
|
L-->>H: Acks / flow control
|
|
end
|
|
H->>E: Verify checksum / signature
|
|
H->>E: Exit programming, reset if needed
|
|
H-->>F: Return success/failure
|
|
else
|
|
F-->>P: Skip flashing
|
|
end
|
|
```
|
|
|
|
## Implementation notes
|
|
|
|
- `ecu_framework/flashing/hex_flasher.py` is a stub — replace with your protocol implementation (UDS/XCP)
|
|
- Validate timing requirements and chunk sizes per ECU
|
|
- Consider power-cycle/reset hooks via programmable poewr supply.
|
|
|
|
## Error handling
|
|
|
|
- On failure, the fixture calls `pytest.fail("ECU flashing failed")`
|
|
- Make flashing idempotent when possible (can retry or detect current version)
|
|
|
|
## Configuration example
|
|
|
|
```yaml
|
|
flash:
|
|
enabled: true
|
|
hex_path: "firmware/ecu_firmware.hex"
|
|
```
|