Category:Linux SDK

Structure

• 上电 ——> Bootloader —[传递参数]—> 加载内核 ——> 内核挂载根文件系统 ——>执行应用程序

• category: bootloader
• category: dtb
• category: Kernel
• category: Rootfs

Example SPI Flash Partition

• Zero V3S - https://licheezero.readthedocs.io/zh/latest/%E7%B3%BB%E7%BB%9F%E5%BC%80%E5%8F%91/SPI_flash_build.html

分区序号	分区大小	分区作用	地址空间及分区名
mtd0	1MB (0x100000)	spl+uboot	0x0000000-0x0100000 : “uboot”
mtd1	64KB (0x10000)	dtb文件	0x0100000-0x0110000 : “dtb”
mtd2	4MB (0x400000)	linux内核	0x0110000-0x0510000 : “kernel”
mtd3	剩余 (0xAF0000)	根文件系统	0x0510000-0x1000000 : “rootfs”

Nano F1C100S - https://whycan.cn/t_2179.html

ID  SIZE    USAGE   ADDR
0   448kb   U-boot  0x0000 0000 - 0x0007 0000
1   64kb    dtb     0x0007 0000 - 0x0008 0000
2   4mb     kernel  0x0008 0000 - 0x0048 0000
3   7.5mb   rootfs  0x0048 0000 - 0x00c0 0000
4   4mb     overlay 0x00c0 0000 - 0x0100 0000   

• Structure 2
• 0x0 u-boot
• 0x40000 dtb -> device tree
• 0x50000 kernel -> kernel
• 0x510000 rootfs -> root file system

Pack Image Firmware

二进制bin 打包 Zero V3S

以16M 大小flash镜像打包脚本为例：

dd if=/dev/zero of=flashimg.bin bs=1M count=16 &&\
dd if=$YOUR_UBOOT_FILE of=flashimg.bin bs=1K conv=notrunc &&\
dd if=$YOUR_DTB_FILE of=flashimg.bin bs=1K seek=1024  conv=notrunc &&\
dd if=$YOUR_KERNEL_FILE of=flashimg.bin bs=1K seek=1088  conv=notrunc &&\
mkdir rootfs
tar -xzvf $YOUR_ROOTFS_FILE -C ./rootfs &&\
cp -r $YOUR_MOD_FILE  rootfs/lib/modules/ &&\
# 为根文件系统制作jffs2镜像包
# --pad参数指定 jffs2大小
# 由此计算得到 0x1000000(16M)-0x10000(64K)-0x100000(1M)-0x400000(4M)=0xAF0000
mkfs.jffs2 -s 0x100 -e 0x10000 --pad=0xAF0000 -d rootfs/ -o jffs2.img &&\
dd if=jffs2.img of=$YOUR_IMG_FILE  bs=1K seek=5184  conv=notrunc &&\

以上脚本通过对一个生成的16M空bin文件填充 uboot、dtb、kernel、rootfs 生成 16M 镜像，如需修改，请注意各个文件的大小，修改成对应地址（注意对齐）。
至此，SPI系统各部分已编译完成，通过sunxi-fel进行烧写即可；

Debug - Segment Fault

Core Dump

• https://licheezero.readthedocs.io/zh/latest/%E5%BA%94%E7%94%A8/debug.html

Toolchain Setup

Pre install

• sudo apt install build-essential checkinstall zlib1g-dev libssl-dev flex bison libncurses5-dev -y

Buildroot

• apt-get install linux-headers-$(uname -r)

Toolchain

• Install ARM GCC

Normal on PC

• gcc: gcc -o helloword helloword.c

Openwrt

• openwrt compiler: /openwrt/staging_dir/toolchain_mispel_...../bin/mispel-openwrt-linux-gcc -o helloword hellworld.c
• to fix error - environment error'STAGING_DIR'not defined, run - export STAGING_DIR=/openwrt/staging_dir/
• to set openwrt complier absoulte directory run - nano /etc/environment, add directory path after ":", run - source environment to make it work, finall command will be mispel-openwrt-linux-gcc

Reference

• USB Gadget - https://linux-sunxi.org/USB_Gadget
• Reference - https://www.thirtythreeforty.net/posts/2019/12/my-business-card-runs-linux/
• Starting linux - https://www.cnblogs.com/schips/p/11393234.html

LPI

• https://licheezero.readthedocs.io/zh/latest/%E7%B3%BB%E7%BB%9F%E5%BC%80%E5%8F%91/bsp_index.html

Full process Zero V3S

• https://whycan.cn/t_3138.html