PetaLinux启动过程解析

Posted 2022-11-28 中国思想史

1、BootROM部分

在器件上电运行后，处理器自动开始Stage-0 Boot，也就是执行片内BootROM中的代码

BootROM会初始化CPU和一些外设，以便读取下一个启动阶段所需的程序代码，FSBL（First

2、BOOT.bin部分

BootROM会去读取MIO[2..8],从而确定启动设备方式（Zynq支持多种启动设备方式,可以使用跳线帽设置），将选定设备的头192Kbyte内容，也就是FSBL，复制到OCM(On Chip Memory)中，并将控制器交给FSBL。

FSBL部分

FSBL启动时可以使用整块256Kb的OCM，当FSBL开始运行后，器件就正式由开发者或用户控制了。Xilinx提供了一份FSBL代码，如果没什么特殊要求，可以直接使用。

嵌入式系统系统启动一般都是在 nor flash （NOR flash 可以直接运行程序，NAND flash需要将程序加载到内存运行，和 Bios 很类似，nor flash 成本很高）。

BIOS是（Basic Input Output System）"基本输入输出系统"

它是一组固化到计算机内主板上一个ROM芯片上的程序，它保存着计算机最重要的基本输入输出的程序、开机后自检程序和系统自启动程序，它可从CMOS中读写系统设置的具体信息。 其主要功能是为计算机提供最底层的、最直接的硬件设置和控制。

RAM（random access memory）即随机存储内存，这种存储器在断电时将丢失其存储内容，故主要用于存储短时间使用的程序。ROM（Read-Only Memory）即只读内存，是一种只能读出事先所存数据的固态半导体存储器。

uboot 就是针对嵌入式环境特别编译准备的一级引导程序。用来初始化环境，并且读取启动 Linux 内核的东西。

因为在u-boot中配置从eMMC启动，所以在u-boot之前会先初始化一些外设,配置PL端资源，如eMMC，下面为初始化eMMC的打印信息。

Device: sdhci@e0100000

Manufacturer ID: fe

OEM: 14e

Name: MMC02

Tran Speed: 52000000

Rd Block Len: 512

MMC version 4.4.1

High Capacity: No

Capacity: 1.8 GiB

Bus Width: 4-bit

Erase Group Size: 512 KiB

HC WP Group Size: 0 Bytes

User Capacity: 1.8 GiB

Boot Capacity: 1 MiB ENH

RPMB Capacity: 128 KiB ENH

u-boot.elf从发eMMC加载image.ub到片上内存DDR3（2G）中

readingimage.ub

11274340 bytes read in 611 ms (17.6 MiB/s)

首先是加载Linux kernel，状态为尚未解压，大小3.8MiB，使用了SHA1安全哈希算法（Secure Hash Algorithm）

## Loading kernel from FIT Image at10000000 ...

  Using 'conf@1' configuration

  Verifying Hash Integrity ... OK

  Trying 'kernel@0' kernel subimage

    Description:  Linux Kernel

    Type:         Kernel Image

    Compression:  uncompressed

    Data Start:   0x100000d4

    Data Size:    4005144 Bytes = 3.8MiB

    Architecture: ARM

    OS:           Linux

    Load Address: 0x00008000

    Entry Point:  0x00008000

    Hash algo:    sha1

    Hash value:  3b953474750d8fb67e6a25dece81e156c4ecdcb2

  Verifying Hash Integrity ... sha1+ OK

接着是加载ramdisk，状态为尚未解压,大小6.9MiB，使用了SHA1安全哈希算法（Secure Hash Algorithm）

## Loading ramdisk from FIT Image at10000000 ...

  Using 'conf@1' configuration

  Trying 'ramdisk@0' ramdisk subimage

    Description:  ramdisk

    Type:         RAMDisk Image

    Compression:  uncompressed

    Data Start:   0x103d686c

    Data Size:    7248902 Bytes = 6.9MiB

    Architecture: ARM

    OS:           Linux

    Load Address: unavailable

    Entry Point:  unavailable

    Hash algo:    sha1

    Hash value:  e934ce35c9f408811fcb859dff09b0aed896871b

  Verifying Hash Integrity ... sha1+ OK

最后是加载fdt（设备树文件），状态为尚未解压，大小18.2KiB，使用了SHA1安全哈希算法（Secure Hash Algorithm）

## Loading fdt from FIT Image at 10000000...

  Using 'conf@1' configuration

  Trying 'fdt@0' fdt subimage

    Description:  Flattened DeviceTree blob

    Type:         Flat Device Tree

    Compression:  uncompressed

    Data Start:   0x103d1ee0

    Data Size:    18649 Bytes = 18.2KiB

    Architecture: ARM

    Hash algo:    sha1

    Hash value:  97ab0c048f0da9de6329b48e1345c2aedc552995

  Verifying Hash Integrity ... sha1+ OK

   Booting using the fdt blob at 0x103d1ee0

   Loading Kernel Image ... OK

   Loading Ramdisk to 07916000, end 07fffc06... OK

   Loading Device Tree to 0790e000, end079158d8 ... OK

引导加载完成，准备运行

解压Linux内核镜像并启动Linux内核，运行在CPU0上

Starting kernel ...

Uncompressing Linux...done, booting the kernel.

Booting Linux on physical CPU0x0

Linux version 4.6.0-xilinx(bjut@virtua-ubuntu1604) (gcc version 5.2.1 20151005 (Linaro GCC 5.2-2015.11-2)) #1 SMP PREEMPT Mon Apr 24 15:03:20 CST 2017

CPU: ARMv7 Processor[413fc090] revision 0 (ARMv7), cr=18c5387d

CPU: PIPT / VIPTnonaliasing data cache, VIPT aliasing instruction cache

Machine model:huanbao_qspi_emmc

bootconsole [earlycon0]enabled

cma: Reserved 16 MiB at0x3f000000

Memory policy: Data cachewritealloc

percpu: Embedded 12pages/cpu @ef7d0000 s19776 r8192 d21184 u49152

Built 1 zonelists in Zoneorder, mobility grouping on.  Totalpages: 260608

Kernel command line:console=ttyPS0,115200 earlyprintk

 

开始解压文件系统镜像

Trying to unpack rootfsimage as initramfs...

Freeing initrd memory:7080K (c7916000 - c8000000)

hw perfevents: enabledwith armv7_cortex_a9 PMU driver, 7 counters available

futex hash table entries:512 (order: 3, 32768 bytes)

workingset:timestamp_bits=28 max_order=18 bucket_order=0

jffs2: version 2.2. (NAND)(SUMMARY)  漏2001-2006 Red Hat, Inc.

bounce: pool size: 64pages

io scheduler noopregistered

io scheduler deadlineregistered

io scheduler cfqregistered (default)

dma-pl330 f8003000.dmac:Loaded driver for PL330 DMAC-241330

dma-pl330 f8003000.dmac:    DBUFF-128x8bytes Num_Chans-8 Num_Peri-4Num_Events-16

42c00000.serial: ttyUL1 atMMIO 0x42c00000 (irq = 167, base_baud = 0) is a uartlite

42c10000.serial: ttyUL2 atMMIO 0x42c10000 (irq = 168, base_baud = 0) is a uartlite

42ca0000.serial: ttyUL3 atMMIO 0x42ca0000 (irq = 169, base_baud = 0) is a uartlite

42cb0000.serial: ttyUL4 atMMIO 0x42cb0000 (irq = 170, base_baud = 0) is a uartlite

42c20000.serial: ttyUL5 atMMIO 0x42c20000 (irq = 171, base_baud = 0) is a uartlite

42c30000.serial: ttyUL6 atMMIO 0x42c30000 (irq = 172, base_baud = 0) is a uartlite

42c40000.serial: ttyUL7 atMMIO 0x42c40000 (irq = 173, base_baud = 0) is a uartlite

42c50000.serial: ttyUL8 atMMIO 0x42c50000 (irq = 174, base_baud = 0) is a uartlite

42c60000.serial: ttyUL9 atMMIO 0x42c60000 (irq = 175, base_baud = 0) is a uartlite

42c70000.serial: ttyUL10at MMIO 0x42c70000 (irq = 176, base_baud = 0) is a uartlite

42c80000.serial: ttyUL11at MMIO 0x42c80000 (irq = 177, base_baud = 0) is a uartlite

42c90000.serial: ttyUL12at MMIO 0x42c90000 (irq = 178, base_baud = 0) is a uartlite

e0000000.serial: ttyPS1 atMMIO 0xe0000000 (irq = 145, base_baud = 3125000) is a xuartps

e0001000.serial: ttyPS0 atMMIO 0xe0001000 (irq = 146, base_baud = 3125000) is a xuartps

郼onsole [ttyPS0] enabled

console [ttyPS0] enabled

bootconsole [earlycon0]disabled

bootconsole [earlycon0]disabled

xdevcfg f8007000.devcfg:ioremap 0xf8007000 to f090c000

[drm] Initialized drm1.1.0 20060810

brd: module loaded

loop: module loaded

m25p80 spi0.0: n25q128a11(16384 Kbytes)

4 ofpart partitions foundon MTD device spi0.0

Creating 4 MTD partitionson "spi0.0":

0x000000000000-0x000000500000: "boot"

0x000000500000-0x000000520000: "bootenv"

0x000000520000-0x000000fa0000: "kernel"

0x000000fa0000-0x000001000000: "spare"

CAN device driverinterface

gpiod_set_value: invalidGPIO

libphy: MACB_mii_bus:probed

[Firmware Warn]:/amba/ethernet@e000b000/mdio/phy@7: Whitelisted compatible string. Pleaseremove

macb e000b000.etherneteth0: Cadence GEM rev 0x00020118 at 0xe000b000 irq 148 (00:0a:35:00:1e:53)

Marvell 88E1111e000b000.etherne:07: attached PHY driver [Marvell 88E1111](mii_bus:phy_addr=e000b000.etherne:07, irq=-1)

e1000e: Intel(R) PRO/1000Network Driver - 3.2.6-k

e1000e: Copyright(c) 1999- 2015 Intel Corporation.

//开始注册驱动

PPP generic driver version2.4.2

PPP BSD Compression moduleregistered

PPP Deflate Compressionmodule registered

PPP MPPE Compressionmodule registered

NET: Registered protocolfamily 24

usbcore: registered newinterface driver asix

usbcore: registered newinterface driver ax88179_178a

usbcore: registered newinterface driver cdc_ether

usbcore: registered newinterface driver net1080

usbcore: registered newinterface driver cdc_subset

usbcore: registered newinterface driver zaurus

usbcore: registered newinterface driver cdc_ncm

usbcore: registered newinterface driver huawei_cdc_ncm

usbcore: registered newinterface driver cdc_mbim

ehci_hcd: USB 2.0'Enhanced' Host Controller (EHCI) Driver

ehci-pci: EHCI PCIplatform driver

ohci_hcd: USB 1.1 'Open'Host Controller (OHCI) Driver

ohci-pci: OHCI PCIplatform driver

ohci-platform: OHCIgeneric platform driver

uhci_hcd: USB UniversalHost Controller Interface driver

usbcore: registered newinterface driver cdc_acm

cdc_acm: USB AbstractControl Model driver for USB modems and ISDN adapters

usbcore: registered newinterface driver cdc_wdm

usbcore: registered newinterface driver usb-storage

usbcore: registered newinterface driver usbserial

usbcore: registered newinterface driver option

usbserial: USB Serialsupport registered for GSM modem (1-port)

e0002000.usb supply vbusnot found, using dummy regulator

ULPI transceivervendor/product ID 0x0424/0x0007

Found SMSC USB3320 ULPItransceiver.

ULPI integrity check:passed.

ci_hdrc ci_hdrc.0: EHCIHost Controller

ci_hdrc ci_hdrc.0: new USBbus registered, assigned bus number 1

ci_hdrc ci_hdrc.0: USB 2.0started, EHCI 1.00

hub 1-0:1.0: USB hub found

hub 1-0:1.0: 1 portdetected

mousedev: PS/2 mousedevice common for all mice

i2c /dev entries driver

rtc-pcf8563 0-0051: chipfound, driver version 0.4.4

rtc-pcf8563 0-0051: rtccore: registered rtc-pcf8563 as rtc0

cdns-i2c e0004000.i2c: 400kHz mmio e0004000 irq 142

Driver for 1-wire Dallasnetwork protocol.

EDAC MC: ECC not enabled

Xilinx Zynq CpuIdle Driverstarted

sdhci: Secure Digital HostController Interface driver

sdhci: Copyright(c) PierreOssman

sdhci-pltfm: SDHCIplatform and OF driver helper

mmc0: SDHCI controller one0100000.sdhci [e0100000.sdhci] using DMA

ledtrig-cpu: registered toindicate activity on CPUs

usbcore: registered newinterface driver usbhid

usbhid: USB HID coredriver

NET: Registered protocolfamily 10

sit: IPv6 over IPv4tunneling driver

NET: Registered protocolfamily 17

can: controller areanetwork core (rev 20120528 abi 9)

NET: Registered protocolfamily 29

can: raw protocol (rev20120528)

can: broadcast managerprotocol (rev 20120528 t)

can: netlink gateway (rev20130117) max_hops=1

Registering SWP/SWPBemulation handler

rtc-pcf8563 0-0051:setting system clock to 2000-04-09 21:55:13 UTC (955317313)

ALSA device list:

  No soundcards found.

mmc0: new high speed MMCcard at address 0001

Freeing unused kernelmemory: 1024K (c0a00000 - c0b00000)

mmcblk0: mmc0:0001 MMC02G1.79 GiB

INIT: mmcblk0boot0:mmc0:0001 MMC02G partition 1 1.00 MiB

version 2.88bootingmmcblk0boot1: mmc0:0001 MMC02G partition 2 1.00 MiB

mmcblk0rpmb: mmc0:0001MMC02G partition 3 128 KiB

mmcblk0: p1

usb 1-1: new high-speedUSB device number 2 using ci_hdrc

hub 1-1:1.0: USB hub found

hub 1-1:1.0: 4 portsdetected

EXT4-fs (mmcblk0rpmb):unable to read superblock

EXT4-fs (mmcblk0rpmb):unable to read superblock

EXT2-fs (mmcblk0rpmb):error: unable to read superblock

FAT-fs (mmcblk0rpmb):unable to read boot sector

EXT4-fs (mmcblk0rpmb):unable to read superblock

EXT4-fs (mmcblk0rpmb):unable to read superblock

EXT2-fs (mmcblk0rpmb):error: unable to read superblock

FAT-fs (mmcblk0rpmb):unable to read boot sector

FAT-fs (mmcblk0rpmb):unable to read boot sector

usb 1-1.1: new high-speedUSB device number 3 using ci_hdrc

mount: mounting/dev/mmcblk0rpmb on /run/media/mmcblk0rpmb failed: Input/output error

mount: mounting/dev/mmcblk0boot0 on /run/media/mmcblk0boot0 failed: Invalid argument

cdc_ether 1-1.1:2.0 usb0:register 'cdc_ether' at usb-ci_hdrc.0-1.1, CDC Ethernet Device,02:1e:10:1f:00:00

//检测到4G模块，启动4G模块

option 1-1.1:2.2: GSMmodem (1-port) converter detected

usb 1-1.1: GSM modem(1-port) converter now attached to ttyUSB0

option 1-1.1:2.3: GSMmodem (1-port) converter detected

mount: mounting/dev/mmcblk0boot1 on /run/media/mmcblk0boot1 failed: Invalid argument

usb 1-1.1: GSM modem(1-port) converter now attached to ttyUSB1

option 1-1.1:2.4: GSMmodem (1-port) converter detected

usb 1-1.1: GSM modem (1-port)converter now attached to ttyUSB2

option 1-1.1:2.5: GSMmodem (1-port) converter detected

usb 1-1.1: GSM modem(1-port) converter now attached to ttyUSB3

option 1-1.1:2.6: GSMmodem (1-port) converter detected

usb 1-1.1: GSM modem(1-port) converter now attached to ttyUSB4

/etc/mdev/mdev-mount.sh:line 28: [: /sys/block/mmcblk0/mmcblk0boot1: binary operator expected

mount: mounting/dev/mmcblk0 on /run/media/mmcblk0 failed: Device or resource busy

random: dd urandom readwith 5 bits of entropy available

Mon Apr 24 07:06:36 UTC2017

Starting internetsuperserver: inetd.

INIT: Entering runlevel: 5

//配置以太网接口，等待网口芯片启动

Configuring networkinterfaces... IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready

done.

// 启动Dropbear并生成密钥，Dropbear是一个相对较小的SSH服务器和客户端(开源软件)。

Starting Dropbear SSHserver: Generating key, this may take a while...

//公钥，用公钥加密数据就必须用私钥解密，如果用私钥加密也必须用公钥解密。

Public key portion is:

ssh-rsaAAAAB3NzaC1yc2EAAAADAQABAAABAQCQWM1vqfFHlIPbduTWsKeX1iQI4HMwuDZ46GV4FgJbtAFG/+9inB9K42p4YR06RrdnPdkvv2cPAQ/srfbm/qgF5BoKGdE32JsLU4EP9ovBecA6xSe2C2yzJ3e1HQOIaHcSWf59QpxTPFUrw+GYHNR4N8WZj6V9XJ+w6/5NWWSTwICjgo2yizVEodjsPc0VChAqmC8EBUz2evgBBJGbzm3mxgHXzsoKD/kKSlw2dtGcPCvO7GSdxYE1hBtk6xb8a6zToVOAPIqZFCnWtfEKUSexUx60I72nZngOtwqZR+ILR6BBLZqpomwc0AONZtjAYRrdIqnVPR2y0irVNIz1JAPx

root@plnx_arm

Fingerprint: md5b4:d4:cf:bc:ad:c0:79:93:89:66:ce:4a:b0:93:a5:2c

dropbear.

//启动PetaLinux成功

Start Hello PetaLinux.

//运行初始化脚本

run init.sh

//配置网络、路由

config network

//启动系统日志

Starting syslogd/klogd:set board time

//启动4G拨号程序，后台运行

run LTEConnection &

done

open /dev/ttyUSB0 SUCCESS

ttyclear:

Starting tcf-agent: OK

PetaLinux 2016.4 plnx_arm/dev/ttyPS0

//网卡芯片启动成功

macb e000b000.etherneteth0: link up (1000/Full)

IPv6:ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

//用户登录系统

plnx_arm login:

//查看系统网卡信息

 

ifconfig

eth0      Link encap:Ethernet  HWaddr 00:0A:35:00:1E:53 

          inet addr:192.168.0.100  Bcast:192.168.0.255  Mask:255.255.255.0

          inet6 addr:fe80::20a:35ff:fe00:1e53%768720/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500 Metric:1

          RX packets:60 errors:0 dropped:0overruns:0 frame:0

          TX packets:10 errors:0 dropped:0overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:6671 (6.5 KiB)  TX bytes:1206 (1.1 KiB)

          Interrupt:148 Base address:0xb000

 

lo        Link encap:Local Loopback 

          inet addr:127.0.0.1  Mask:255.0.0.0

          inet6 addr: ::1%768720/128 Scope:Host

          UP LOOPBACK RUNNING  MTU:65536 Metric:1

          RX packets:8 errors:0 dropped:0overruns:0 frame:0

          TX packets:8 errors:0 dropped:0overruns:0 carrier:0

          collisions:0 txqueuelen:1

          RX bytes:488 (488.0 B)  TX bytes:488 (488.0 B)

 

usb0      Link encap:Ethernet  HWaddr 02:1E:10:1F:00:00 

          inet addr:10.81.49.191  Bcast:10.81.49.255  Mask:255.255.255.128

          inet6 addr:fe80::1e:10ff:fe1f:0%768720/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500 Metric:1

          RX packets:9 errors:0 dropped:0overruns:0 frame:0

          TX packets:15 errors:0 dropped:0overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:1040 (1.0 KiB)  TX bytes:1802 (1.7 KiB)

//查看系统设备信息

root@plnx_arm:~# ls /dev

bus                 null                tty21               tty59

console             port                tty22               tty6

cpu_dma_latency     ppp                 tty23               tty60

full                psaux               tty24               tty61

i2c-0               ptmx                tty25               tty62

initctl             pts                 tty26               tty63

input               ram0                tty27               tty7

kmsg                ram1                tty28               tty8

log                 ram10               tty29               tty9

loop-control        ram11               tty3                ttyPS0

loop0               ram12               tty30               ttyPS1

loop1               ram13               tty31               ttyUL1

loop2               ram14               tty32               ttyUL10

loop3               ram15               tty33               ttyUL11

loop4               ram2                tty34               ttyUL12

loop5               ram3                tty35               ttyUL2

loop6               ram4                tty36               ttyUL3

loop7               ram5                tty37               ttyUL4

mdev.seq            ram6                tty38               ttyUL5

mem                 ram7                tty39               ttyUL6

memory_bandwidth    ram8                tty4                ttyUL7

mmcblk0             ram9                tty40               ttyUL8

mmcblk0boot0        random              tty41               ttyUL9

mmcblk0boot1        rtc0                tty42               ttyUSB0

mmcblk0p1           shm                 tty43               ttyUSB1

mmcblk0rpmb         snd                 tty44               ttyUSB2

mtab                tty                 tty45               ttyUSB3

mtd0                tty0                tty46               ttyUSB4

mtd0ro              tty1                tty47               urandom

mtd1                tty10               tty48               usbmon0

mtd1ro              tty11               tty49               usbmon1

mtd2                tty12               tty5                vcs

mtd2ro              tty13               tty50               vcs1

mtd3                tty14               tty51               vcsa

mtd3ro              tty15               tty52               vcsa1

mtdblock0           tty16               tty53               vga_arbiter

mtdblock1           tty17               tty54               watchdog

mtdblock2           tty18               tty55               watchdog0

mtdblock3           tty19               tty56               xdevcfg

network_latency     tty2                tty57               zero

network_throughput  tty20               tty58

//系统关机过程：

oot@plnx_arm:~# shutdown-h now

Broadcast message fromroot@plnx_arm (ttyPS0) (Fri Oct 20 11:28:20 2017):

The syste@J蛠going down for system halt NOW!

INIT: Switching to runlev

//改变系统runlevel,0表示关机

//向系统进程发送中断信号

INIT: Sending processesthe TERM signal

//停止Dropbear SSH server

root@plnx_arm:~# StoppingDropbear SSH server: stopped /usr/sbin/dropbear (pid 1160)

dropbear.

 //停止Linux系统

Stop Hello PetaLinux.

//停止系统日志进程

Stopping syslogd/klogd:stopped syslogd (pid 1173)

stopped klogd (pid 1175)

done

Stopping tcf-agent:random: nonblocking pool is initialized

FAIL

//清空网络接口的配置

Deconfiguring networkinterfaces... done.

Sending all processes theTERM signal...

//退出用户登录

logout

macb e000b000.etherneteth0: link down

Sending all processes theKILL signal...

//卸载远程文件系统和本地文件系统

Unmounting remotefilesystems...

Deactivating swap...

Unmounting localfilesystems...

//系统关机完成

reboot: System halted

附加信息：

Linux系统有7个运行级别(runlevel)

 

Linux系统有7个运行级别(runlevel)

运行级别0：系统停机状态，系统默认运行级别不能设为0，否则不能正常启动

运行级别1：单用户工作状态，root权限，用于系统维护，禁止远程登陆

运行级别2：多用户状态(没有NFS)

运行级别3：完全的多用户状态(有NFS)，登陆后进入控制台命令行模式

运行级别4：系统未使用，保留

运行级别5：X11控制台，登陆后进入图形GUI模式

运行级别6：系统正常关闭并重启，默认运行级别不能设为6，否则不能正常启动

 

多数的桌面的linux系统缺省的runlevel是5，用户登陆时是图形界面，而多数的服务器版本的linux系统缺省的runlevel是3，用户登陆时是字符界面，runlevel 1和2除了调试之外很少使用，runlevel s和S并不是直接给用户使用，而是用来为Single user mode作准备。

在基于Busybox的系统上执行busybox --list即可看到一个系统可用命令列表