Re: [PATCH 1/2] nova-core: Add a library for bitfields in Rust structs

[John Hubbard <jhubbard@nvidia.com>]

On 9/4/25 4:06 AM, Alexandre Courbot wrote:
> On Thu Sep 4, 2025 at 4:16 PM JST, Danilo Krummrich wrote:
>> On Thu Sep 4, 2025 at 5:16 AM CEST, Alexandre Courbot wrote:
>>> On Thu Sep 4, 2025 at 12:15 AM JST, Joel Fernandes wrote:
>>> <snip>
>> 	pub struct PageTableEntry {
>> 	    63:63     nx          as bool,
>> 	    62:52     available2  as u16,
>> 	    51:12     pfn         as u64,
>> 	    11:9      available   as u8,
>> 	    1:1       writable    as bool,
>> 	    0:0       present     as bool,
>> 	}
>>
>> This is also what would be my preferred style for the kernel in general.
> 
> Sorry for the confusion. The discussion was whether to keep using the
> `H:L` syntax of the current macro, or use Rust's inclusive ranges syntax
> (i.e. `L..=H`), as the `genmask_*` macros currently do.
> 

The H:L (for example "11:9 available as u8", above) is elegant and readable.

The Rust native syntax "L..=H", much less so.

For this part of the kernel, dealing specifically with bits, feel pretty
strongly that we should go with "H:L".


thanks,
-- 
John Hubbard