5 ms·

"...when the developer does not have access to, say, a big-endian system to test with." Currently, the most accessible big-endian platform that I know of is th

by chasil 2y ago

"...when the developer does not have access to, say, a big-endian system to test with." Currently, the most accessible big-endian platform that I know of is the Raspberry Pi running NetBSD. https://wiki.netbsd.org/ports/evbarm/ https://wiki.netbsd.org/ports/evbarm/

kev009 2y ago
NetBSD's cross build system (http://www.netbsd.org/docs/guide/en/chap-build.html http://www.netbsd.org/docs/guide/en/chap-build.html) is such a joy to use for odd systems like this. Lately I have been playing around with a Ubiquiti EdgeRouter-4 (Octeon MIPS64) which is also big endian. Great little platform for home routing and serving under BSD.
- mistrial9 2y ago
  oh, is this true ? '' FreeBSD can be booted on Octeon from disk or network using an ELF kernel through U-Boot with the “bootoctlinux” command. '' FreeBSD is not Linux (obviously) so this is making a command named something-linux to boot FreeBSD? seems humiliating somehow
  - kev009 2y ago
    FreeBSD no longer supports MIPS, I wrote NetBSD in my comment. bootoctlinux is the command Cavium added to U-boot to boot an ELF kernel. You can alias it as something else if it makes you feel proud.
ajb 2y ago
Wow I did not know that was still possible. Big-endian seems to be something of Thomasson[1] these days. I wonder if there is any real use case apart from testing code to see if it still runs on old machines. [1] https://en.m.wikipedia.org/wiki/Hyperart_Thomasson https://en.m.wikipedia.org/wiki/Hyperart_Thomasson
- BLKNSLVR 2y ago
  First time I've come across the Thomasson concept. Thanks for the reference and link.
  - sandebert 2y ago
    You might like this episode of 99 Percent Invisible: https://99percentinvisible.org/episode/thomassons/ https://99percentinvisible.org/episode/thomassons/
- deleted 2y ago
  [deleted]
- kev009 2y ago
  Mainframe OSes including mainframe Linux are Big Endian. Maybe mainframe Linux could switch but thus far it has not, it seems unlikely the other mainframe OSes would want to. AIX is also Big Endian and seems unlikely to switch and will be supported until at least 2040. Personally, I find big endian a lot more natural when doing hardware development. I understand there are people who think the opposite. As far as performance it is negligible.. network order is Big, PCIe is little so you are usually eating some conversion on either platform. I also really don't understand why people thought it was such a hard concept as to largely force Linux (PPC, arm, mips) toward little.
  - userbinator 2y ago
    I also really don't understand why people thought it was such a hard concept as to largely force Linux (PPC, arm, mips) toward little. Working with arbitrary-precision arithmetic makes you realise how logical little-endian is (and how weird they appear on a big-endian machine.)
    - tyingq 2y ago
      I think it's negligible, but you don't have to byte swap for network order with big endian.
    - 2y ago
deleted 2y ago
[deleted]

by chasil 2y ago

kev009 2y ago

NetBSD's cross build system (http://www.netbsd.org/docs/guide/en/chap-build.html http://www.netbsd.org/docs/guide/en/chap-build.html) is such a joy to use for odd systems like this. Lately I have been playing around with a Ubiquiti EdgeRouter-4 (Octeon MIPS64) which is also big endian. Great little platform for home routing and serving under BSD.

mistrial9 2y ago
oh, is this true ? '' FreeBSD can be booted on Octeon from disk or network using an ELF kernel through U-Boot with the “bootoctlinux” command. '' FreeBSD is not Linux (obviously) so this is making a command named something-linux to boot FreeBSD? seems humiliating somehow
- kev009 2y ago
  FreeBSD no longer supports MIPS, I wrote NetBSD in my comment. bootoctlinux is the command Cavium added to U-boot to boot an ELF kernel. You can alias it as something else if it makes you feel proud.

ajb 2y ago

Wow I did not know that was still possible. Big-endian seems to be something of Thomasson[1] these days. I wonder if there is any real use case apart from testing code to see if it still runs on old machines. [1] https://en.m.wikipedia.org/wiki/Hyperart_Thomasson https://en.m.wikipedia.org/wiki/Hyperart_Thomasson

BLKNSLVR 2y ago
First time I've come across the Thomasson concept. Thanks for the reference and link.
- sandebert 2y ago
  You might like this episode of 99 Percent Invisible: https://99percentinvisible.org/episode/thomassons/ https://99percentinvisible.org/episode/thomassons/
deleted 2y ago
[deleted]
kev009 2y ago
Mainframe OSes including mainframe Linux are Big Endian. Maybe mainframe Linux could switch but thus far it has not, it seems unlikely the other mainframe OSes would want to. AIX is also Big Endian and seems unlikely to switch and will be supported until at least 2040. Personally, I find big endian a lot more natural when doing hardware development. I understand there are people who think the opposite. As far as performance it is negligible.. network order is Big, PCIe is little so you are usually eating some conversion on either platform. I also really don't understand why people thought it was such a hard concept as to largely force Linux (PPC, arm, mips) toward little.
- userbinator 2y ago
  I also really don't understand why people thought it was such a hard concept as to largely force Linux (PPC, arm, mips) toward little. Working with arbitrary-precision arithmetic makes you realise how logical little-endian is (and how weird they appear on a big-endian machine.)
  - tyingq 2y ago
    I think it's negligible, but you don't have to byte swap for network order with big endian.
  - 2y ago

deleted 2y ago

[deleted]