# Before You Start
This document provides guidance on how to port the Linux and LiteOS Cortex-A kernels on the OpenHarmony small system to a development board. It is intended for developers with experience in developing embedded systems. Before following instructions in this document, it is recommended that you familiarize yourself with [OpenHarmony](../../OpenHarmony-Overview.md), including its technical architecture, directory structure, kernel subsystem, and driver subsystem. The following table lists the development boards that have been adapted to the small system.
**Table 1** Development boards compatible with the OpenHarmony small system
Development Board
|
Kernel
|
Architecture
|
ROM
|
RAM
|
File System
|
Flash Type
|
hispark_taurus
|
LiteOS Cortex-A and Linux 4.19
|
Arm Cortex-A7
|
8 GB
|
1 GB
|
VFAT, EXT4
|
eMMC4.5
|
hispark_aries
|
LiteOS-A
|
Arm Cortex-A7
|
16 MB
|
512 MB
|
JFFS2
|
SPI NOR
|
In addition to the aforementioned development boards, LiteOS Cortex-A and Linux 4.19 can be ported to development boards that meet the requirements described in the table below.
**Table 2** Requirements for porting OpenHarmony small system kernels
Kernel
|
Supported Architecture
|
ROM
|
File System
|
Flash Type
|
LiteOS-A
|
ARMv7
|
> 2 MB
|
VFAT, JFFS2, YAFFS2
|
SPI NOR, NAND, eMMC
|
Linux 4.19
|
ARM, Arm64, MIPS, x86
|
> 5 MB
|
VFAT, JFFS2, YAFFS, EXT/2/3/4, NFS
|
NOR, NAND, eMMC
|