How to modify the partition table of db845c installed when using android 11

After re-compiling the aosp project, the error below occurred:
error: out/target/product/db845c/boot.img too large 231004576 > 67108864

After modity the boot partition size in , the issue resolved.

But when I fastboot flashing the boot.img to db845c, error occurred for not enough
space left in “boot” partition.

Is there any way to modify the partition table for re-config the partitions for db845c ?
Which file should be modified and shall I change the code of bootloader ?
Thank you so much.