5 ms·

In that case, you might be better off using a MIPS based device (old router, maybe?), since ARM is gaining popularity.

• kbenson 12y ago
  From what I've heard recently, targetting ARM may be problematic because two ARM processors may not support the same features, or function the same way. Then again, maybe there's a low-end subset of ARM instructions that should work an any chip, similar to the instruction set for the i386?
  • wtracy 12y ago
    The Arm specification primarily focuses on the protected mode opcodes used by applications. This is why Arm application binaries are portable across machines. The real mode opcodes needed to bring up a kernel are a mess on Arm, with each manufacture using their own instruction set.
    • pjc50 12y ago
      This explanation is garbled. The opcodes are not fundamentally different (although more are added from ARMv6 to ARMv7 e.g. the Pi 1 to Pi 2 transition), and there isn't the X86 different set of "real mode" opcodes. What is different is the boot sequence and system register layout. On a PC you can write one bootloader that works across multiple systems because either the peripherals are at the same place or BIOS/UEFI code is provided to sort it out for you. This is not the case on ARM; uboot and devicetree are attempts to fix it.
  • justincormack 12y ago
    You can feature detect at runtime. And or pick a subset. It is complicated but workable.