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embedded-linuxyoctobitbake

bitbake not producing a zImage file

I've been running a Yocto build in bitbake for a few days, but I've noticed it sometimes stops producing the zImage file of my kernel. Most of the changes I'm making are to the kernel config, and the machine.conf file. when this happens, I still get updated tar.gz files with each build, but the zImage stops being updated. Running the do_clean, do_cleanall and do_cleansstate tasks do not help, and neither does deleting the old zImage file from build/tmp/deploy. The only thing that helps is deleting the entire pocky/build/tmp directory and rebuilding the entire project from scratch. Here is my current machine.conf file:

#@TYPE: Machine 
#@Name: EMAC, Inc. SoM-9G45M Module 
#@DESCRIPTION: Machine.inc configuration for the SoM-9G45M board with a at91sam9g45 processor 

TARGET_ARCH = "arm" 

PREFERRED_PROVIDER_virtual/kernel = "linux-2.6.30-at91-emac" 
PREFERRED_PROVIDER_xserver = "xserver-kdrive" 
KERNEL_IMAGETYPE = "zImage" 
KERNEL_EXTRA_ARGS = "LOADADDR=0x74000000"

#don't try to access tty1 
USE_VT = "0" 
MACHINE_FEATURES = "kernel26 apm alsa ext2 usbhost usbgadget" 
KERNEL_DEVICETREE = "at91som9g45.dtb"

# used by sysvinit_2 
#SERIAL_CONSOLE = "115200 ttyS1" 
SERIAL_CONSOLE = "115200 ttyS0" 
#SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1"
#SYSLINUX_DEFAULT_CONSOLE = "console=ttyS0"
#SYSLINUX_SERIAL = "0 115200"
#SYSLINUX_SERIAL_TTY = "console=ttyS0,115200"
#EXTRA_IMAGECMD_jffs2 = "--pad=0xA00000 --little-endian --eraseblock=0x20000" 

# NAND
MKUBIFS_ARGS = " -e 129024 -c 2047 -m 2048  -x lzo"
UBINIZE_ARGS = " -m 2048 -p 128KiB -s 512"

UBI_VOLNAME = "rootfs"

UBOOT_MACHINE = "${MACHINE}_nandflash_config"
UBOOT_ENTRYPOINT = "0x74000000"
UBOOT_LOADADDRESS = "0x74000000"

require include/at91sam9.inc

What can cause a bitbake build to stop producing the specified kernel image, and how do I fix it?

Solution

  • The answer ended up having two parts.

    First, running bitbake -c do_cleansstate linux-at91 and then bitbake core-image-sato successfully regenerated the zImage file.

    Second, linux-2.6.30-at91-emac was incorrect since my kerenl was just called linux-at91. So my kernel build was likely only being run when I ran builds for other machines.

    So my full image build wasn't rebuilding the kernel because I had referenced a different kernel. Once I fixed that, the kernel build would start running again. I'm not sure how I got a zImage in the first place, or why bitbake never threw an error after being told to build a kernel that didn't exist.