x86系统


内核


获取内核源码

git clone https://github.com/torvalds/linux.git


生成最小配置

make tinyconfig


修改配置

make menuconfig
  • 64-bit Kernel (CONFIG_64BIT=y)
  • General Setup –> Configure standard kernel features (expert users) –> Enable support for printk (CONFIG_PRINTK=y)
  • General Setup –> Initial RAM filesystem and RAM disk (initramfs/initrd) support (CONFIG_BLK_DEV_INITRD=y)
  • General Setup –>kernel compression mode (Gzip) (CONFIG_RD_GZIP=y)
  • Executable file formats –> Kernel support for ELF binaries (CONFIG_BINFMT_ELF=y)
  • Executable file formats –> Kernel support for scripts starting with #! (CONFIG_BINFMT_SCRIPT=y)
  • File systems –> Pseudo filesystems –> /proc file system support (CONFIG_PROC_FS=y)
  • Device Driver –> Character devices –> Enable TTY (CONFIG_TTY=y)
  • Device Driver –> Character devices –> Serial Drivers –> 8250/16550 and compatible serial support (CONFIG_SERIAL_8250=y)
  • Device Driver –> Character devices –> Serial Drivers –> Console on 8250/16550 and compatible serial port (CONFIG_SERIAL_8250_CONSOLE=y)


内核编译

make -j4


生成内核 arch/x86/boot/bzImage，(Size ≈ 800K).


文件系统


编译脚本

git clone https://github.com/hacker-jie/kernel-utils.git


生成initramfs

./kernel-utils/mk-initrd

弹出选择，都选n，生成内核 ./kernel-utils/initramfs.cpio.gz，(Size ≈ 1.3M).


QEMU测试

qemu-system-x86_64 -kernel [PATH_TO_KERNEL]/arch/x86/boot/bzImage -initrd [PATH_TO_ROOTFS]/initramfs.cpio.gz -m 32M -nographic -append "init=/bin/sh console=ttyS0"



树莓派3 (64位)


内核


获取内核源码

git clone https://github.com/raspberrypi/linux.git


生成最小配置

make tinyconfig


修改配置

make menuconfig

CONFIG_BINFMT_ELF
CONFIG_BLK_DEV_INITRD
CONFIG_RD_GZIP
CONFIG_PRINTK
CONFIG_TTY
CONFIG_PROC_FS
CONFIG_DEVTMPFS (optional)
CONFIG_DEVTMPFS_MOUNT (optional)

CONFIG_ARCH_BCM2835
CONFIG_MAILBOX
CONFIG_BCM2835_MBOX
CONFIG_RASPBERRYPI_FIRMWARE
CONFIG_SERIAL_AMBA_PL011
CONFIG_SERIAL_AMBA_PL011_CONSOLE


内核编译

make -j4


生成内核 arch/arm64/boot/Image.

*注：编译器用 aarch64-linux-gnu, (sudo apt install -y gcc-aarch64-linux-gnu).


文件系统


与前述方法一致。


QEMU测试

qemu-system-aarch64 -M raspi3b -kernel [PATH_TO_KERNEL]/arch/arm64/boot/Image -dtb [PATH_TO_DTB]/bcm2710-rpi-3-b.dtb -initrd [PATH_TO_ROOTFS]/initramfs.cpio.gz -m 1024M -nographic -append "init=/bin/sh console=ttyAMA0,115200"