Kernel Fusing Boot Loader tftp Contents JTAG Interface
Kernel Fusing (Boot Loader & tftp 활용)
Contents • • JTAG Interface Flash ROM memory block Boot Loader Commands Image Fusing – – Boot Loader : empos_boot Kernel : z. Image RAM disk : ramdisk 16. gz Qtopia : qtopia. jffs (jffs image)
JTAG Write • Direct write: JTAG interface (download and erase + write) • Indirect write: tftp protocol + boot loader command – tftp empos_booter, flash booter Target Board command DRAM area (128 Mbytes) Boot loader (0 x 0 c 000) 0 x 0000 – 0 xa 3 d 0 0000 Link PC 1 st port Tftp: /tftpboot/dlfile Ethernet NFS: /nfs_resources kernel (0 x 10 0000) 0 x 000 c 0000 - 0 xa 00 c 0000 RAMdisk (0 x 60 0000) 0 x 0020 0000 – 0 xa 060 0000 /usr (0 x 170 0000) 0 x 90 0000 – 0 xa 160 0000 Working space Flash ROM: 32 Mbutes JTAG port Parallel port JTAG I/F Jflash-Xcale dlfile command
Memory Map • Flash ROM area + SDRAM area SDRAM Area (128 Mbyes) Flash ROM Area (32 Mbyes) 0 xa 800 0000 0 x 200 0000 /usr (user space) 0 x 90 0000 0 x 80 0000 null Boot loader (temporary) ramdisk 0 x 20 0000 0 x 1 c 0000 null Kernel Image 0 xc 0000 0 x 8 0000 0 x 0 0000 ramdisk Environment values null Boot loader Kernel Image 0 xa 00 c 0000
Jflash-Xscale command
Download using Boot Loader
Boot Loader • Boot Loader 수행 화면
Status Commands • Memory Map, Network Status, Register Value
Experiment: Kernel fusing • • Interface 설정: serial port, Ethernet, JTAG interface Target board의 상태 확인: status (boot loader) Set environment: IP address(setip), MAC address(macwrite) tftp를 이용하여 데이터 전송 – tftp empos_booter – tftp z. Image kernel – tftp ramdisk 16, gz ramdisk • Flash ROM에 저장: flash command – flash booter, flash kernel, flash ramdisk, flash usr • 필요한 경우 삭제: erase command – erase kernel – erase 0 x 0 0 xc 0000
Example of Kernel Fusing
Fusing Files 경로 및 파일명 /Image/bootloader/empos_boot /Image/kernel/z. Image /Image/filesystem/ramdisk 16. gz 설 명 부트로더 커널 램디스크 /Image/filesystem/qtopia. jffs user 영역(qtopia용 jffs 이미지) /Image/filesystem/tinyx. jffs user 영역(tinyx용 jffs 이미지)
Experiment • 개발환경에 맞도록 kernel과 RAM disk를 fusing – IP address, bootp, tftp 등 – Hosts – Herald message • Jflash-Xscale 소스 분석과 memory map 이해 – Flash ROM 구조(block mode)에 따른 Jflash-Xscale 소스를 분 석 • Report – Jffs, ext 2 파일 구조 조사
- Slides: 12