Claude review: gpu: nova-core: require little endian

Claude Code Review Bot
2026-04-12T04:47:45Z

Patch Review

**Verdict: Looks good.**

The one-line diff is straightforward:

```
depends on 64BIT
depends on PCI
depends on RUST
+ depends on !CPU_BIG_ENDIAN
select AUXILIARY_BUS
```

**Observations:**

1. **Placement is correct.** The new `depends on` line is placed after the existing `depends on` lines and before the `select` lines, following standard Kconfig ordering conventions.

2. **The LE assumption is real.** The driver uses `FromBytes` (which does native-endian reinterpretation of byte slices) on several packed structs in `vbios.rs:332,392,550,854`. It also uses explicit `u32::from_le_bytes()` / `u16::from_le_bytes()` in `falcon.rs:432,461` and `vbios.rs:445,449,490,502,510,515,795,840`. The mixture of explicit LE conversion and raw byte reinterpretation confirms that the driver would not work correctly on a big-endian system — some data would be byte-swapped and some wouldn't.

3. **The commit message's RUST claim is slightly imprecise.** The message says "RUST transitively depends on !CPU_BIG_ENDIAN" — this isn't strictly true via Kconfig dependency chains. What is true is that on arm64 (the only 64-bit arch where `CPU_BIG_ENDIAN` exists), `CPU_BIG_ENDIAN` currently `depends on BROKEN`, making it impossible to select in practice. The patch is still valuable because it makes the requirement explicit rather than relying on an indirect and potentially fragile transitive constraint. The below-the-cut explanation acknowledges this nuance, which is good.

4. **Minor nit on the commit message:** The phrase "all the code that reads RPCs out of the command queue just directly interprets the bytes" could be more precise — the vbios parsing code with `FromBytes` is arguably a better example of implicit LE assumptions than the RPC code.

No blocking issues. The patch is a single-line, obviously-correct Kconfig dependency addition.

---
Generated by Claude Code Patch Reviewer