在linux启动时候,串口log中会打印cmdline
- [ 0.000000] c0 0 (swapper) Kernel command line: earlycon androidboot.selinux=permissive uart_dma keep_dbgclk_on clk_ignore_unused initrd=0xd0000000,38711808 rw crash_page=0x8f040000 initrd=/recoveryrc boot_reason=0x2000 ota_status=0x1001 在linux启动完成后,通过 cat /proc/cmdline也是可以看到cmdline. 那么cmdline是如何添加的呢?
1、 在dts中的bootargs中添加
- / {
-
model = "xxx yyyyyyy FPGA";
-
compatible = "xxx ,yyyyy-fpga", "xxx ,yyyyyy";
-
chosen {
-
/*
-
* initrd parameters not set in dts file since the ramdisk.img size
-
* need to check in uboot, and the initrd load address and size will
-
* set in uboot stage.
-
*/
-
bootargs = "earlycon androidboot.selinux=permissive uart_dma keep_dbgclk_on clk_ignore_unused";
-
stdout-path = "serial0:115200";
-
};
- ......
- } 2、在BoardConfig中添加 vim device/xxx/xxx_evb/BoardConfigCommon.mk
- BOARD_KERNEL_CMDLINE += androidboot.selinux=enforcing androidboot.hardware=xxxxx_phone androidboot.dtbo_idx=0 3、在uboot中添加 vim u-boot/common/cmd_bootm.c
- append_bootargs("recovery=1");
- sprintf(dm_buf,"init=/init skip_initramfs rootwait root=/dev/dm-0 dm="system none ro,0 1 android-verity /dev/mmcblk0p%d"",ret);
- append_bootargs((const char *)dm_buf);
4、在android的Makefile中添加 vim build/core/Makefile
- INTERNAL_KERNEL_CMDLINE := $(strip $(BOARD_KERNEL_CMDLINE) buildvariant=$(TARGET_BUILD_VARIANT) $(VERITY_KEYID))
- ifdef INTERNAL_KERNEL_CMDLINE
- INTERNAL_BOOTIMAGE_ARGS += --cmdline "$(INTERNAL_KERNEL_CMDLINE)"
- endif 《ARMv8/ARMv9架构学习系列课程》全系列,共计52节课,超16h的视频课程