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I know ARM in principal supports BE, but never heard real BE ARM products yet. Is there one? I am just curious.
by kbumsik 5y ago
I know ARM in principal supports BE, but never heard real BE ARM products yet. Is there one? I am just curious.
- tyingq 5y agoThe hardware products support setting endianness at boot time. It's just a matter of OS's supporting BE mode. Netbsd releases big endian versions that work on various ARM boards. Here's an announcement showing it works on an Rpi3 and below, for example: https://mail-index.netbsd.org/port-arm/2020/12/03/msg007117.html https://mail-index.netbsd.org/port-arm/2020/12/03/msg007117.... They said at the time that it's not yet working on the Rpi4 because of issues getting BE mode and UEFI to work together. I don't know that it's used often, but it does exist.
- howinteresting 5y agoWhy would anyone want to use BE mode at all?
- tyingq 5y agoHandy for testing that your code doesn't have any endian bugs that might crop up if someone tried compiling it on older RISC hardware? Or perhaps very slightly more efficient networking code, since big endian is the default order for many operations there?
- gsnedders 5y agoIt used to be much more common than it is nowadays; commonality between desktop systems used for development and production has slowly got rid of it. I know certain TVs and set-top boxes at least used to use big-endian, but mostly them long-ago migrated to little-endian nowadays.
- brandmeyer 5y agoTMS570 dual-lockstep automotive safety controllers are hardwired to be big-endian. Their close cousins the RM57 line look like nearly identical parts that are little-endian. I believe, but cannot prove, that the only difference in silicon is a factory one-time-programmable setting (fuse). "Why would anyone want to build a BE machine?" In this case, they are trying to gain market-share from big-endian POWER microcontrollers.