本文适用针对于ARMv8-A64指令集的编译器环境搭建。 关于arm的交叉编译环境可以总结以下几点：
- aarch64-linux-gnu： ARMv8的64位架构编译，指令集A64，Linux应用编译。
- aarch64-linux-gnu_ilp32: ARMv8的32位架构编译，指令集A32/T32，Linux应用编译。
- aarch64-none-elf: ARMv8， 64位的裸机编译，指令集A64。
- arm-linux-gnueabi: ARMv7全指令集， ARMv8 aarch32（A32/T32）指令集，Linux应用。
- arm-none-eabi: ARMv7全指令集， ARMv8 aarch32（A32/T32）指令集，裸机应用。
| multiarch name | syscall ABI | instruction set | endianness | word size | description | spec documents |
|---|---|---|---|---|---|---|
| aarch64-linux-gnu | linux | ARMv8 | little | 64 | aarch64 Linux Platform | AAPCS64 (ARM IHI 005A)1 ELF for the ARM 64-bit Architecture2 |
| aarch64_be-linux-gnu | linux | ARMv8 | big | 64 | aarch64 Linux Platform | AAPCS64 (ARM IHI 005A)1 ELF for the ARM 64-bit Architecture2 |
| aarch64-linux-gnu_ilp32 | linux | ARMv8 | little | 32 | aarch64 Linux Platform | |
| aarch64_be-linux-gnu_ilp32 | linux | ARMv8 | big | 32 | aarch64 Linux Platform | |
| arm-linux-gnu | linux | ARMv7/ARMv8 | little | 32 | Old ARM ABI | APCS (ARM DUI 0041 chapter 9)4 |
| arm-linux-gnueabi | linux | ARMv7/ARMv8 | little | 32 | ARM EABI, soft-float | AAPCS (ARM IHI 0042D)5 ARM GNU/Linux ABI Supplement6 |
| arm-linux-gnueabihf | linux | ARMv7/ARMv8 | little | 32 | ARM EABI, hard-float | AAPCS (ARM IHI 0042D)5 and XXXXX (TBD) |
| armeb-linux-gnueabi | linux | ARMv7/ARMv8 | big | 32 | ARM EABI, soft-float | AAPCS (ARM IHI 0042D)5 ARM GNU/Linux ABI Supplement6 |
| armeb-linux-gnueabihf | linux | ARMv7/ARMv8 | big | 32 | ARM EABI, hard-float | AAPCS (ARM IHI 0042D)5 and XXXXX (TBD) |
| armv8l-linux-gnueabihf | linux | ARMv8 | little | 32 | ARMv8 EABI, hard-float | |
| arm-eabi | Bare-Metal | ARMv7/ARMv8 | little | 32 | ARM EABI, soft-float | |
| armeb-eabi | Bare-Metal | ARMv7/ARMv8 | big | 32 | ARM EABI, soft-float | |
| aarch64-elf | Bare-Metal | ARMv8 | little | 64 | ARMv8 EABI, hard-float | |
| aarch64_be-elf | Bare-Metal | ARMv8 | big | 64 | ARMv8 EABI, hard-float |
- test.o使用 aarch64-none开头编译的文件，运行在armv8架构上面
- test.elf使用 arm-none开头编译的文件，运行在armv7架构的
➜ test file test.o
test.o: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, for GNU/Linux 3.7.0, with debug_info, not stripped
➜ test file test.elf
test.elf: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 3.2.0, with debug_info, not stripped$ brew tap PX4/homebrew-px4
$ brew update
$ brew install gcc-arm-none-eabi-83`
$ arm-none-eabi-gcc --version
arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 8-2019-q3-update) 8.3.1 20190703 (release) [gcc-8-branch revision 273027]
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.下载地址: https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/downloads 中国下载太慢可以使用清华镜像：https://mirror.tuna.tsinghua.edu.cn/armbian-releases/_toolchain/
brew install openocd
自己编译带树莓派4b的qemu
$ git clone git@github.com:0xMirasio/qemu-patch-raspberry4.git --depth=1
$ ./configure --target-list=aarch64-softmmu
$ make -j8
$ make install
$ qemu-system-aarch64 -machine raspi3b -nographic -kernel xxxx.bin -S -s
不需要树莓派4b支持的可以直接：
$ brew install qemu
$ aarch64-none-elf-gdb --tui xxxx.elf -x xxxx.sh