Can I use my custom file system on SD Card

[saram.kim]

I made own AArch64 filesystem using yocto.
and make EXT4 partition on SD Card
and copy the filesystem.

There is no boot partition on bootargs or cmdline.

So how can I use my SD card partition(ie. /dev/mmcblk1p1) as boot partition
instead of default Android system partition.

[danielt]

You might get some clues from:

Getting Linux on Mediatek?

According to my logbook t looks like I configured, built and installed the kernel using the following commands: make amt6797_64_open_defconfig # mmcblk0p27 is the system partition (fastboot flash system rootfs.img) scripts/config \ --enable CMDLINE_FORCE --set-str CMDLINE \ 'console=ttyMT0,921600n1 root=/dev/mmcblk0p27 rw vmalloc=496M maxcpus=5 mrdump.lk=MRDUMP04 mrdump_rsvmem=0x46000000,0x400000,0x44800000,0x9c280 lcm=1-nt35695_fhd_dsi_cmd_truly_nt50358_drv fps=6000 vram=29229056 boot_reason…

I put my custom rootfs in the on-board flash but the proceedure (based on compiling a kernel with a command line built in) should be the same for rootfs on SD card.