Tizen v2.3 Bootup · Commonly used device drivers U-boot 录结构 /u-boot board common doc drivers include lib net examples fs rtc tools post arch disk api ... – interrupt_init

Embedded Software Lab. @ SKKU

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Tizen v2.3 Bootup


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• Bootloader(U-boot) – Bootloader 概述 – U-boot

• Systemd – Systemd 概述 – Platform Bootup – Parsing Unit File

内容


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Bootloader(U-boot)


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• 引导加载程序 – 将机器id和启动参数传递给内核

Tizen bootup 概述

ROM codePower on Booting device

Bootloader

Kernel

Platform


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• 引导加载程序是什么? – 引导加载程序是当系统初始化时的第⼀一个执⾏行程序(在主程序前，例如内核)

– 引导加载程序是⼀一个计算机程序,在⾃自检完成后加载主程序(即操作系统内核)

• 为什么需要引导加载程序? – 给出了⼀一个开发环境 – 节省了flash读写的成本 – 给加载任何操作系统提供灵活性

什么是引导加载程序bootloader


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• 引导加载程序的不同类型是什么? – Boot-ROM ( or Pre-Boot Loader)

• ⼩小代码加载第⼀一阶段引导加载程序

– First Stage Boot Loader • ⼩小段代码初始化 NAND/MMC & DRAM控制器。

– Second Stage Boot Loader • 第⼆二阶段的引导加载程序的主要功能是内核加载到RAM或直接跳跃到内核的开始。

引导加载程序的类型

Pre-Bootloader First-StageBootloader

Second-StageBootloader OS Kernel


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Exynos4412

U-boot 加载过程

Internal ROM

Internal SRAM

Cortex-A9DRAM controller DRAM

Booting Device (NAND, MMC, SD,

USB)

eSSD controller

NAND controller

SD/MMC controller

UART/USB

1st BL2nd BL

OS

iROM code1

2

3


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• BL0; iRom code (boot-rom or pre-boot loader) – 简单的平台⽆无关的代码存储在内部ROM – 初始化基本功能(时钟,栈,堆,等等) – 加载第⼀一阶段引导加载程序(从启动设备内部存储器)

• BL1; first boot loader – 简单的平台⽆无关的代码存储在外部存储器(引导设备) – 加载第⼆二引导加载程序 – 初始化 NAND/MMC & DRAM控制器

• BL2; second boot loader – 平台依赖复杂的代码存储在外部存储器中 – 初始化时钟,UART – 从引导装载操作系统映像DRAM的⼿手段 – 跳转到操作系统

U-boot 加载过程


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Tools to build S-Record or U-boot images

Example code for standalone applications

Filesystem code (cramfs, ext2, jffs2, etc.)

Header files

Files generic to all architectures

Networking code

Power on self test

Real time clock drivers

Machine/arch independent API

Architecture specific files

Board dependent files

Misc architecture independent functions

Code for disk drive partition handling

Documentation

Commonly used device drivers

U-boot ⺫⽬目录结构

/u-boot

board

common

doc

drivers

include

lib

net

examples

fs

rtc

tools

post

arch

disk

api

/u-boot


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1. 禁⽤用所有中断 2. 从ROM将所有初始化数据复制到RAM 3. 清空未初始化的数据区域 4. 分配和初始化堆栈空间 5. 初始化处理器的堆栈指针 6. 创建并初始化堆 7. 执⾏行所有全局数据的初始化 8. 启⽤用中断 9. 调⽤用主循环

U-boot 编码顺序


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U-boot 编码顺序

Setup SP for Early Board Setup Environment (ASM->C)

Calculate Addresses (SP, Dest, GD) for Relocation

General Relocation

Copy Binary to RAM

Fix Relocation

Clear BSS

Setup SP for Common Board Setup

Setup GD and JUMP to Final Board Setup

Low Level Initialization

lowlevel_init

cpu_init_crit

Disable MMU

Invalidate and disable Instruction & data Cache

Disable IRQ &FIQ. Switch to supervisor mode

cpu/armv7/start.S reset()

Reset CPU and Hardwarecpu/armv7/start.S

_start()

arm/lib/crt0.S_main()

Early Board Setup

arm/lib/crt0.Sboard_init_f()

arm/lib/crt0.Sboard_init_r()board/samsung/lowlevel_init.S

lowlevel_init()

cpu/armv7/start.S relocate_code()

Jump into main loop


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• _start() /* Entry point function */ • reset() /* Reset CPU configurations */

– save_boot_params() /* Save boot parameters */ – Disable the FIQ & IRQ – Switch to supervisor mode – cpu_init_crit()

• Invalidate I, D Cache • Disable I cache if CONFIG_SYS_ICACHE_OFF • Disable MMU • lowlevel_init()

• _main() /* setup initial stack & global data. And jump to C routine for board initialization */

U-boot 编码顺序


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• board_init_f() – arch_cpu_init // basic arch cpu dependent setup – board_early_init_f // early board initialization, UART pin setting – timer_init // initialize timer – env_init // initialize mmc/sdcard environment – init_baudrate // initialize baudrate settings – serial_init // serial communication setup – console_init_f // stage 1 init of console, configure console from console.c – display_banner // say that we are here, print u-boot banner – print_cpuinfo // display cpu info – checkboard // display board info – init_func_i2c // initialize I2C – dram_init // configure available RAM backs – arm_pci_init

U-boot 编码顺序


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• board_init_r() – board_init // setup chipselects specific configuration – logbuff_init_ptrs // initialize default log level – mem_malloc_init // configure malloc area – nand_init mmc_init // initialize flash/mmc – env_relocate // relocate environment or set NULL – stdio_init // setup stdio ready for use – api_init // initialize API – console_init_r // fully init console as a device – arch_misc_init // miscellaneous arch dependent initialization – misc_init_r // miscellaneous platform dependent initialization – interrupt_init // set up exceptions – enable_interrupts // enable exceptions – board_late_init // board late initialization – eth_initialize // setup ethernet – main_loop // jump to main loop & waiting for commands from console

U-boot 编码顺序


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U-boot 编码顺序

Jump to kernel image address

main_loop()

Autoboot_mode()

Command_mode()

boot() loads() flash()tftpboot()

Input command

Wait for 3 seconds Key pressed within 3 seconds


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通过U-boot加载

SDRAM

RootFile-System

Kernel

Booting device

Kernel Image

Bootloaderuboot

Root File System

Reset

Bootloaderuboot

CPU

Optional compressed


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• 打包uImage – When the kernel is complied, mkimage attaches image_header to kernel

image

• 解包uImage – Magin number ! CRC check ! decompress ! get board information !

kernel booting

通过U-boot加载

#define IH_MAGIC 0x27051956 /* Image Magic Number */ #define IH_NMLEN 32 /* Image Name Length */ typedef struct image_header { uint32_t ih_magic; /* Image Header Magic Number */ uint32_t ih_hcrc; /* Image Header CRC Checksum */ uint32_t ih_time; /* Image Creation Timestamp */ uint32_t ih_size; /* Image Data Size */ uint32_t ih_load; /* Data Load Address */ uint32_t ih_ep; /* Entry Point Address */ uint32_t ih_dcrc; /* Image Data CRC Checksum */ uint8_t ih_os; /* Operating System */ uint8_t ih_arch; /* CPU architecture */ uint8_t ih_type; /* Image Type */ uint8_t ih_comp; /* Compression Type */ uint8_t ih_name[IH_NMLEN]; /* Image Name */ } image_header_t;


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• Architecture dependent setup – setup_arch() [/arch/arm/kernel/setup.c]

• Exception(or trap) initialization – trap_init() [/arch/arm/kernel/trap.c]

• Interrupt initialization – init_IRQ() [/arch/arm/kernel/irq.c] – sotfirq_init() [/kernel/sotfirq.c]

• Scheduler initialization – sched_init() [/kernel/sched.c]

• Timer initialization – time_init() [/arch/XXX/kernel/time.c]

• Console initialization – console_init() [/driver/char/tty_io.c]

• Module initialization – init_module() [/kernel/module.c]

start_kernel


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• 内存和系统初始化,缓存和缓冲初始化,⽂文件系统初始化 – kmem_cache_init() [/mm/slab.c] – mem_init() [/arch/a,r/mm/init.c] – kmem_cache_size() [/mm/slab.c] – fork_init() [/kernel/fork.c] – proc_caches_init() [/kernel/fork.c] – vfs_caches_init() [/fs/dcache.c] – buffer_init() [/fs/buffer.c] – page_cache_init() [/mm/filemap.c] – signals_init() [/kernel/signal.c] – proc_root_init() [/fs/proc/root.c] – ipc_init() [/ipc/util.c]

• init process creation – rest_init() [/init/main.c]

start_kernel


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systemd


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• Sysvinit – userspace launch (PID 1) – ⼀一次只有⼀一个进程运⾏行 – 直接启动系统,然后sleep直到下⼀一次重新启动

• Systemd – Default init in Fedora 15 and later Leonard Poettering (2009) – 改善软件框架来表达依赖性 – 允许在系统启动时同时或并⾏行处理更多的过程 – 减少计算开销。

什么是systemd?


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• Systemd in Tizen – System and service manager for tizen systemd – Ver. 43 (download http://www.freedesktop.org/software/systemd/) – Parallelizes service execution – Socket and D-Bus activation for starting services and daemon – on-demand starting of daemons – Managing the service processes as a group using Linux cgroup – Supporting automount points – Snapshotting and restoring of services

什么是systemd?

http://www.freedesktop.org/software/systemd/


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systemd 体系结构


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• systemd Utility – 监测和控制systemd本⾝身和它的服务 – “systemctl”开发⼈人员可以查询或发送控制命令对systemd服务管理者 – 'systemd-journalctl' ⽤用于查看⽇日志⽂文件

• systemd target – Tizen启动过程分开在不同的离散步骤，每个步骤使⽤用“target”单元同步点来分组单位 – 每个⺫⽬目标的启动过程是⾼高度并⾏行,具体⺫⽬目标单位在这样的顺序下的到达具有不确定性

• systemd daemon – Tizen平台系统和服务管理者 – 作为初始化系统 – 'systemd' daemonruns as user session with '--user' option – 'systemd-journald' is a system service that collects and stores log data from the

Kernel, from user processes via syslog or STDOUT/STDERR



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• systemd core – 管理所有单元如 service, socket, mount 等等, 储存所有的⽇日志数据. – controlled by using systemd utility like 'systemctl'

• systemd library & Linux Kernel – systemd requires to enable 'cgroup' and 'autofs' option in Kernel configuration – It also depends on dbus and some libraries such as libnotify, libudev



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• 早期启动脚本 – Most of file system are mounted and systemd related daemons are launched

平台启动– sysinit.target

basic.target

sysinit.target

multi-user.target

graphical.target

bootmode.target

Kernel

local-fs.target

swap.target

socket.target

-.mount boot.mount csa.mount fsck-root.service media.mount opt-usr.mount opt.mount remount-rootfs.service resize2fs-root.service systemd-remount-api-vfs.service var-run.mount

dev-hugepages.mount dev-mqueue.mount proc-sys-fs-binfmt_misc.automount sys-fs-fuse-connections.mount sys-kernel-config.mount sys-kernel-debug.mount sys-kernel-security.mount systemd-ask-password-console.path systemd-binfmt.service systemd-journald.service systemd-modules-load.service systemd-random-seed-load.service systemd-readahead-collect.service systemd-readahead-replay.service systemd-sysctl.service systemd-tmpfiles-setup.service dbus.socket

systemd-initctl.socket systemd-journald.socket systemd-shutdownd.socket telnetd.socket udev-control.socket udev-kernel.socket


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• 基础启动 – All necessary initialization for general purpose daemons are completed

平台启动 – basic.target

basic.target

sysinit.target

multi-user.target

graphical.target

bootmode.target

Kernel

opt-var-kdb-db-libsqlfs.service opt-var-kdb-db-smack-labels.service smack-default-labeling.service systemd-tmpfiles-clean.timer tizen-debug-level.service udev-trigger.service udev.service vconf-setup.service


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• 选择启动模式 – If kernel boot parameter has ‘charger_detect_boot’, the platform boots up as charging mode

平台启动 – bootmote.target

basic.target

sysinit.target

multi-user.target

graphical.target

bootmode.target

Kernel

bootmode-charging.service bootmode-graphical.service


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• 设置⼀一个⽆无图形⽀支持的多⽤用户系统 – Launching platform infrastructure daemons (such as dbus, power manager, gps manager, telephony daemon,

WRT security daemon, media server, systemd-related daemons)

平台启动 – multi-user.target

basic.target

sysinit.target

multi-user.target

graphical.target

bootmode.target

Kernel

alarm-server.service avsystem.service bluetooth-address.service bluetooth-frwk-service.service bluetooth.service dbus.service dlog-main.service dlog-radio.service getty.target gps-manager.service media-server.service nfc-manager.service power-manager.service pulseaudio.service secure-storage.service sensor-framework.service system-server.service systemd-ask-password-wall.path systemd-logind.service systemd-user-sessions.service telephony.service


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• 设置⼀一个图形环境 – System user session for app privilege daemons such as Enlightenment (window manager) – Special target for middleware & mobile service

平台启动 – graphical.target

basic.target

sysinit.target

multi-user.target

graphical.target

bootmode.target

Kernel

core-efl.target

tizen-middleware.target

boot-animation.service cbhm.service e17.service indicator.service osp-app-service.service quickpanel.service scim.service starter.path xmodmap.service xrdb.service

ac.service [email protected] [email protected] [email protected]

calendar.service contacts-service.service download-provider.service email.service msg-service.service pushd.service sound-server.service

tizen-mobile-session.targetwrt-preinstall-widgets.service

xorg.targetxorg.service


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Systemd 分析


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• systemd – 控制从initramfs移动到Tizen平台的systemd – Run hardware init and fs mount, etc services – 启动流程运⾏行⼏几个单元(.target)

• 不同的⺫⽬目标可以并⾏行运⾏行 – 许多linux发⾏行版采⽤用systemd作为默认

• Red Hat Enterprise Linux, CentOS, Fedora, Arch Linux, openSUSE – 不要使⽤用守护进程控制脚本t(/sbin/init, /etc/init.d/*, /etc/rc*.d) – /usr/lib/systemd

• unit files: service, target, socket, device, mount, automount, path, snapshot, swap, timer

• systemd utilities: systemctl, notify, analyze, cgis, cgtop, logictl, journalctl, nspawn

平台启动


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• https://wiki.tizen.org/wiki/Porting_Guide

平台启动

entry point

.target vs .service• .target; service grouping• .service; process run


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• /usr/lib/systemd/system

• cat sysinit.target

解析单元⽂文件 – ⽰示例 (1/8)

target to parse


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• Website – http://www.freedesktop.org/wiki/software/systemd/

• systemd download – http://www.freedesktop.org/software/systemd/


manpage

http://www.freedesktop.org/wiki/software/systemd/

http://www.freedesktop.org/software/systemd/


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Can search all function and unit, configuration of systemd

enter target index


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target unit file


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Description on unit file option


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• User awareness unit name = “System Initialization”• If emergency is running, wait• Run with local-fs.target, swap.target, sysinit.target.wants• Run after local-fs.target, swap.target, emergency.service, emergency.target• User can control service start and stop


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• [Unit], [Service], [Install], [Socket], [Swap], [Mount], … – example; telephony.service – [Unit]; general options

• unit name = Telephony daemon • Run after modem.service

– [Service]; process options • Run telephony-daemon as main process

– [Install]; actual work of unit excute • Create telephony.service symlink at multi-user.target.wants

不同的会话


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• systemd official Site http://www.freedesktop.org/wiki/Software/systemd/

• systemd FAQ (written by developer) – http://0pointer.de/blog/projects/the-biggest-myths

References

http://www.freedesktop.org/wiki/Software/systemd/

http://www.freedesktop.org/wiki/Software/systemd/

Documents

Tizen v2.3 Bootup · Commonly used device drivers U-boot 录结构 /u-boot board common doc drivers include lib net examples fs rtc tools post arch disk api ... – interrupt_init