rust-embedded
do validation when parsing serde yaml/json
I was handcrafting some svd (yaml) and early on ran into a generator issue.
To reproduce run the following in an empty directory:
cargo init simple_bit_field_failure \
&& cd simple_bit_field_failure \
&& cargo add cortex_m vcell \
&& cd src \
&& echo """
name: MyDevice
version: 0
description: My Device
addressUnitBits: 32
width: 32
peripherals:
- name: MyPeripheral
baseAddress: 0xb8000300
registers:
- register:
name: MyRegister
description: My register.
addressOffset: 0
size: 1
fields:
- name: MyBitField
description: My bit field.
bitRange: \"[0:0]\"
""" | RUST_LOG=debug svd2rust --strict --source_type yaml \
&&cargo fmt -- --config normalize_doc_attributes=true \
&&cargo build
result:
...
error[E0308]: mismatched types
--> src/lib.rs:779:37
|
779 | MY_BIT_FIELD_R::new(self.bits)
| ------------------- ^^^^^^^^^ expected `bool`, found `u8`
| |
| arguments to this function are incorrect
|
...
The first doc line reports version:
//!Peripheral access API for MYDEVICE microcontrollers (generated using svd2rust v0.28.0 ( ))
After delving into the generator sources it turns out that register 'size' above is measured in bits instead of bytes as I was using it.
This uncovers a broken corner case in the logic for computing use_cast in register.rs.
Fixing support for single-bit registers is not very urgent I guess ;-)
On a more serious note: should the generator have complained that bit fields beyond the register width were specified in my project?
no need to dive in code. there is specification https://www.keil.com/pack/doc/CMSIS/SVD/html/elem_special.html#registerPropertiesGroup_gr
I knew that site but seeing uncompilable code generated I also 'knew' it was a bug and had to dive in. It's my knee-jerk reaction :-/