[PATCH v1 0/5] Add support for LoongArch32

[Adhemerval Zanella Netto]

On 02/12/25 11:14, Xi Ruoyao wrote:
> On Tue, 2025-12-02 at 20:57 +0800, mengqinggang wrote:
>> These patches are based on Jiajie Chen's previous work[1].
>> The binutils and gcc patches is here[2] [3].
>> The binutils and gcc source code can also be find at here[4] [5].
>> A Chinese LA32R instruction set manual is here[6].
>> There is currently no separate LA32 instruction set manual.
>> The LA64 instruction set manual[7] specifies the instructions
>> available in LA32.
> 
> Generally Glibc does not take a Linux port until Linus' kernel tree
> supports the machine.  Maybe LA32 isn't a completely new port, but the
> spirit should be the same: if the ABI between kernel and userspace isn't
> defined yet, Glibc developers are not in a position to define it.

If the kABI is not already in the Linus tree I think it should be marked
as RFC.  

And it is not clear to me how the kABI is handled, it seems to
use the same arch-syscall.h as lp64, with the difference of mmap2 instead
of mmap. But with any other syscall as-is. Does it mean that ilp32
uses the same kABI as lp64, with off_t, time_t, etc as 64-bit (as
x32)?

At least for x32, it uses a masked syscall mechanism to handle some
corner cases; it is not clear if or how loongarch32 requires it.  But
it is not also clear if you intend to allow multilib support (as x86)
or if this is handle as new abi (as for aarch64 and arm32).

> 
> And I think the epoch symbol version of LA32 should be GLIBC_2.43
> instead of GLIBC_2.36.
> 
> And, as a new 32-bit port (or sub-port) IMO we should start to force the
> use of 64-bit time_t on the first day we add it, instead of repeating
> the nasty and still ongoing time_t transition for the existing 32-bit
> ports in the (not so far) future.
>