下载时选择什么架构好呢？没有ARM V8可以选啊？
x86_64
mipsel_mips32
powerpc_8548
riscv64_riscv64
powerpc_464fp
mipsel_74kc
mipsel_24kc
mipsel_24kc_24kf
arm_mpcore
mips64_octeonplus
arm_cortex-a9_vfpv3-d16
i386_pentium-mmx
arm_xscale
i386_pentium4
mips_mips32
arm_fa526
mips_4kec
mips_24kc
arm_arm1176jzf-s_vfp
arm_cortex-a7
aarch64_cortex-a72
arm_cortex-a15_neon-vfpv4
arm_cortex-a9_neon
aarch64_generic
aarch64_cortex-a53
arm_cortex-a9
arm_arm926ej-s
arm_cortex-a7_vfpv4
arm_cortex-a8_vfpv3
arm_cortex-a7_neon-vfpv4
arm_cortex-a5_vfpv4
