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From https://www.gnu.org/software/hurd/faq/64-bit.html https://www.gnu.org/software/hurd/faq/64-bit.html > There are currently no plan for 64-bit userland, but
by lol768 7y ago
From https://www.gnu.org/software/hurd/faq/64-bit.html https://www.gnu.org/software/hurd/faq/64-bit.html
> There are currently no plan for 64-bit userland, but there are plans for 64-bit kernelland with 32-bit userland, which will notably permit to efficiently make use of more than 2 GiB memory and provide 4 GiB userland addressing space. Work on this is currently in the master-x86_64 and port-amd64 branches for GNU Mach.
> That being said, you can always run a 32-bit version on a 64-bit machine, it just works, processes are just limited to a couple GiB available memory.
- StudentStuff 7y agoDebian x32 has a pretty similar concept wrt more efficient memory usage: https://wiki.debian.org/X32Port https://wiki.debian.org/X32Port
- chrisseaton 7y agoYou can also store pointers for more than 4 GB in a 32 bit address by compressing them.
- comradesmith 7y agoBut you are still using 32 bit registers so your load and save instructions can't really make use of compressed addresses
- deleted 7y ago[deleted]
- nerdponx 7y agoI don't really understand how all this stuff works at the kernel level, but if you have a 64-bit kernel what would prevent you from also having 64-bit user programs?
- _wmd 7y agoThere is quite a lot of surface area between a program and the kernel - C library, dynamic linker, system call interface, memory layout, droves of permission and sanity checking logic etc. that would need to be updated too. A 64 bit kernel is a first step