(1)命令執行追溯

Sourcebuild/envsetup.sh

Make bootimage -j10

(2)bootimage 目標執行如下

core/main.mk:859:.PHONY:bootimage

core/main.mk:860:bootimage:$(INSTALLED_BOOTIMAGE_TARGET)

(3)執行envsetup.sh指令碼，把(TARGET_DEVICE)/BoardConfig.mk包含了進來

build/envsetup.sh:628:    localTOPFILE=build/core/envsetup.mk

-->build/core/envsetup.mk:161:          $(shell test -d device && find device -maxdepth 4 -path '*/$(TARGET_DEVICE)/BoardConfig.mk

下面為裡面的內容

BOARD_KERNEL_CMDLINE :=console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0 androidboot.hardware=qcommsm_rtb.filter=0x237 ehci-hcd.park=3 androidboot.bootdevice=7824900.sdhcilpm_levels.sleep_disabled=1 loglevel=8 earlyprintk=msm_hsl_uart,0x78b0000

CPXXXBoardConfig.mk:80:BOARD_KERNEL_PAGESIZE    := 2048

CPXXX/BoardConfig.mk:79:BOARD_KERNEL_BASE        := 0x80000000

CPXXX/AndroidBoard.mk:34:includekernel/AndroidKernel.mk

(4)具體如下：

Build/core/Makefile

INSTALLED_RAMDISK_TARGET :=$(BUILT_RAMDISK_TARGET)

BUILT_RAMDISK_TARGET:= $(PRODUCT_OUT)/ramdisk.img

》》》》》-----------------------kernel

INSTALLED_KERNEL_TARGET :=$(PRODUCT_OUT)/kernel

INTERNAL_BOOTIMAGE_ARGS:= \

 477        $(addprefix --second ,$(INSTALLED_2NDBOOTLOADER_TARGET)) \

 478        --kernel $(INSTALLED_KERNEL_TARGET)

CPXXX/AndroidBoard.mk:36:$(INSTALLED_KERNEL_TARGET):$(TARGET_PREBUILT_KERNEL) | $(ACP)

Kernel/AndroidKernel.mk:77 TARGET_PREBUILT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)

 build/core/Makefile: TARGET_PREBUILT_INT_KERNEL := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image.gz-dtb

《《《《---------------------------kernel

INTERNAL_BOOTIMAGE_ARGS +=--ramdisk $(INSTALLED_RAMDISK_TARGET)

INTERNAL_BOOTIMAGE_ARGS+= --cmdline "$(BOARD_KERNEL_CMDLINE)"

INTERNAL_BOOTIMAGE_ARGS+= --base $(BOARD_KERNEL_BASE)

INTERNAL_BOOTIMAGE_ARGS+= --pagesize $(BOARD_KERNEL_PAGESIZE)

INSTALLED_BOOTIMAGE_TARGET := $(PRODUCT_OUT)/boot.img

 $(INSTALLED_BOOTIMAGE_TARGET):$(MKBOOTIMG) $(INTERNAL_BOOTIMAGE_FILES)$(BOOT_SIGNER)

 509        $(call pretty,"Target boot image: [email protected]")

 510       $(hide) $(MKBOOTIMG) $(INTERNAL_BOOTIMAGE_ARGS)$(BOARD_MKBOOTIMG_ARGS) --output [email protected]

 511        $(BOOT_SIGNER) /boot [email protected]$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VERITY_SIGNING_KEY).pk8$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VERITY_SIGNING_KEY).x509.pem [email protected]

 512        $(hide) $(callassert-max-image-size,[email protected],$(BOARD_BOOTIMAGE_PARTITION_SIZE))

上面標紅的一行解析如下，也就是編譯生成boot.img的命令

build/core/Makefile:513:out/host/linux-x86/bin/mkbootimg --kernel out/target/product/CPXXX/kernel--ramdisk out/target/product/CPXXX/ramdisk.img --cmdline"console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0androidboot.hardware=qcom msm_rtb.filter=0x237 ehci-hcd.park=3androidboot.bootdevice=7824900.sdhci lpm_levels.sleep_disabled=1 loglevel=8earlyprintk=msm_hsl_uart,0x78b0000" --base 0x80000000 --pagesize 2048

[email protected]代表目標的值，如果有多個值會一個一個替換

執行mkbootimg的help如下：

[email protected]:~/code/L_6.0_8976/LA.BR.1.3.4-01810-8976.0$out/host/linux-x86/bin/mkbootimg --help

usage: mkbootimg

       --kernel <filename>

       [ --ramdisk <filename> ]

       [ --second<2ndbootloader-filename> ]

       [ --cmdline <kernel-commandline> ]

       [ --board <boardname> ]

       [ --base <address> ]

       [ --pagesize <pagesize> ]

       [ --id ]

       -o|--output<filename>    //--------------------------輸出到目標檔案