[U-Boot] building u-boot x86 with device tree disabled , still refers to device tree function

[Ding, ChiX]

Hi there
I'm building u-boot as payload for x86 platform. I didn't enable device tree in menuconfig (CONFIG_OF_CONTROL is not set) because I use a board config file coreboot.h. When I built u-boot, it reports error during linking stage : undefined reference to dm_scan_fdt_dev

arch/x86/lib/built-in.o:(.u_boot_list_2_uclass_2_lpc+0x8): undefined reference to `dm_scan_fdt_dev'
common/built-in.o:(.u_boot_list_2_uclass_2_usb_hub+0x8): undefined reference to `dm_scan_fdt_dev'
drivers/built-in.o:(.u_boot_list_2_uclass_2_pch+0x8): undefined reference to `dm_scan_fdt_dev'
drivers/pci/built-in.o:(.u_boot_list_2_uclass_2_pci+0x8): undefined reference to `dm_scan_fdt_dev'
drivers/spi/built-in.o:(.u_boot_list_2_uclass_2_spi+0x8): undefined reference to `dm_scan_fdt_dev'
drivers/usb/host/built-in.o:(.u_boot_list_2_uclass_2_usb+0x8): more undefined references to `dm_scan_fdt_dev' follow
Makefile:1189: recipe for target 'u-boot' failed

I looked at the code and see arch/x86/lib/lpc-uclass.c refers to a function "dm_scan_fdt_dev " which is defined in drivers/core/root.c and it looks like a device tree function


UCLASS_DRIVER(lpc) = {
        .id             = UCLASS_LPC,
        .name           = "lpc",
        .post_bind      = dm_scan_fdt_dev,
};

Because device tree isn't enabled, the function isn't compiled and causes the problem while linking.
It's only compiled when the following is true
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
If I comment out the line, it would compile and build. But I'm not sure if it's the right way to do it.

Is it normal behavior? I thought that when not enabling device tree, the code shouldn't use device tree function?
Can anyone help on this please?


Thanks alot,
Chi


--------------------------------------------------------------
Intel Research and Development Ireland Limited
Registered in Ireland
Registered Office: Collinstown Industrial Park, Leixlip, County Kildare
Registered Number: 308263


This e-mail and any attachments may contain confidential material for the sole
use of the intended recipient(s). Any review or distribution by others is
strictly prohibited. If you are not the intended recipient, please contact the
sender and delete all copies.