Subject: Re: LP64 build problem
To: Emmanuel Dreyfus <firstname.lastname@example.org>
From: Jason R Thorpe <email@example.com>
Date: 01/09/2002 13:32:20
On Wed, Jan 09, 2002 at 09:59:32PM +0100, Emmanuel Dreyfus wrote:
> Well, if I remove -Werror to get this problem corrected, I can build a
> LP64 kernel. This kernel is able to boot, but because system calls are
> completely broken, init dies quickly.
I seriously doubt it's an LP64 kernel.
> In fact there is a padding problem because sizeof(register_t) is not
> equal to sizeof(mips_regs_t), hence when you write(2, 0x7fff40b0, 6),
> the kernel understands write(0, 2, 0).
The mips_reg_t should probably die in favor of actually using register_t
> In fact I'm surprised it's even able to create the init process, I
> really expected fatal pmap problems.
If you're using 32-bit addresses, the pmap should still be "fine". (Some
MIPS ports already use a 64-bit paddr_t).
> To be honest I am. I'm now hang on o32 compatibility because of a
> strange VM problem. I'd like to go foward with the system call
> emulation, and n32 is an opportunity to do so. Hence I'd by happy to
> have a LP64 kernel running just our current o32 userland and N32
> binaries. Don't worry, I won't commit theses changes, I understood that
> this is not The Right Way nor The Desired Way.
Well, doing it as a bunch of quick hacks and "fixes" isn't the appropriate
way to go about this. You're attacking the n32 problem in a very ad-hoc
way. If you really want to support n32, then you should support it the
Honestly, what you should be doing is tracking down your o32 VM problem.
> I don't need to be able to natively build N32 binaries in order to work
> on IRIX n32 emulation... anyway, working on 64 bit support on the Mips
> is an interesting project, and I'm okay to work on this too, so please
> tell me where I can gather information about all the changes that need
> to happen (I still have to buy 'see mips run')
No, you don't need to be able to build native n32 binaries, but you need
to be able to build a working n32-capable kernel.
-- Jason R. Thorpe <firstname.lastname@example.org>