ubuntu-mips team mailing list archive

[LIU Qi <liuqi82@xxxxxxxxx>]

On Wed, Aug 05, 2009 at 05:59:14AM +0200, Siggy Brentrup wrote:
 > On Mon, Aug 03, 2009 at 17:45 +0800, LIU Qi wrote:
 > 
 > > Currently the Linux kernel for Loongson is already 64-bit capability.
 > 
 > Not only for Loongson, current kernels report mips64 even on a 32bit
 > Indy, even ancient r4k mipsen seem to support 64 bit.
 > 
 > Please bear with me trying to understand terms you are throwing
 > around, as of this writing I didn't find precise definitions for o32,
 > n32 and n64.  This neat little table sums up what I deduced from
 > context.
 > 
 >     +-----+----------------------+--------------------+
 >     |     | Kernel address space | Userland           |
 >     +-----+----------------------+--------------------+
 >     | o32 | 32 bit       (< 4GB) | 32 bit     (< 3GB) |
 >     +-----+----------------------+--------------------+
 >     | n32 | 64 bit   (unlimited) | 32 bit     (< 3GB) |
 >     +-----+----------------------+--------------------+
 >     | n64 | 64 bit   (unlimited) | 64 bit (unlimited) |
 >     +-----+----------------------+--------------------+
 > 
 > Figures in parentheses mean amount of usable memory, virtual for
 > userland, physical for kernel space.  unlimited means in pratice,
 > mathematically correct: 2^64 B.
 > 
 > Please correct me if I got anything wrong.
Yes, the main differences between different ABIs lay on the registers
usages, length of data type, address space and so on. More details could
be gotten by Google. And also you could refer to the book "see mips
run" and some specifications. Thanks.

Regards,
Qi
-- 
 LIU Qi

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