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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?
/ { 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"; }; ...... }
vim device/xxx/xxx_evb/BoardConfigCommon.mk
BOARD_KERNEL_CMDLINE += androidboot.selinux=enforcing androidboot.hardware=xxxxx_phone androidboot.dtbo_idx=0
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);
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