FreeBSD kernel compile

Delete and re-download the kernel source

• Delete own kernel source
  rm -rf /usr/src
• Download the kernel source
  axel -avn3 http://mirrors.ustc.edu.cn/freebsd/releases/amd64/12.1-RELEASE/src.txz
  
  
• Extract the kernel source
  tar xvzfp src.txz -C /

Modify kernel parameters

• Enter the corresponding kernel directory, the virtual machine is AMD64
  cd /usr/local/amd64/conf
• Modify kernel parameters, using the mode profile is introduced:
  
• cp GENERIC code
  • vi code#加入include　　code_kern
  • vi code_kern # add the following

  • options IPFIREWALL
    options IPFIREWALL_VERBOSE
    options IPFIREWALL_VERBOSE_LIMIT=3
    options IPFIREWALL_DEFAULT_TO_ACCEPT
    options IPFIREWALL_NAT
    options DUMMYNET
    options LIBALIAS
    options HZ=1000
    options NULLFS
    options VIMAGE

• config code

Recompile the kernel

• Directory compiled into the kernel 
  cd /usr/local/amd64/compile/code
• Cleanup dependencies
  make cleandepend
• Re-build dependencies
  make depend
• Compile
  make
• installation
  make install
• Restart the serverreboot
• Using the following a command cd ../compile/code;make cleandepend; make depend; make; make install; reboot