On 2/16/2011 3:04 PM, H. Peter Anvin wrote: > On 02/16/2011 11:22 AM, H.J. Lu wrote: >> Hi, >> >> I updated x32 psABI draft to version 0.2 to change x32 library path >> from lib32 to libx32 since lib32 is used for ia32 libraries on Debian, >> Ubuntu and other derivative distributions. The new x32 psABI is >> available from: >> >> https://sites.google.com/site/x32abi/home > I'm wondering if we should define a section header flag (sh_flags) > and/or an ELF header flag (e_flags) for x32 for the people unhappy about > keying it to the ELF class...
For what it's worth, the Tilera 64-bit architecture (forthcoming) includes support for a 32-bit compatibility layer that is similar to x32. It uses 64-bit registers throughout (e.g. for double and long long), but 32-bit addresses. The addresses between 2GB and 4GB are not directly usable as 64-bit addresses since we sign-extend all 32-bit values to make the ISA more straightforward. We use the "compat" layer to provide our syscall table, since we don't have a traditional compatibility layer in this mode (unlike x86_64 and i386). We differentiate the 64-bit and 32-bit binaries just by the Elf class, a proposed by H.J. above. This seems plausible given that it does capture the differences correctly; everything else is the same, just the Elf class. (And we use /lib vs /lib32 on the 64-bit platform to support the 32-bit shared libraries, etc.) -- Chris Metcalf, Tilera Corp. http://www.tilera.com
