用Qemu模拟vexpress-a9 （三）--- 实现用u-boot引导Linux内核

环境介绍

Win7 64 + Vmware 11 + ubuntu14.04 32

u-boot 版本：u-boot-2015-04

Linux kernel版本：linux-3.16.y

busybox版本：1_24_stable

交叉编译工具链：arm-linux-gnueabi-

qemu版本：stable-2.4

概述

这里我采用的方法是，利用网络引导的方式启动Linux内核。具体方式如下：

开启Qemu的网络支持功能，启动u-boot，设置u-boot的环境变量，u-boot采用tftp的方式将uImage格式的Linux内核下载到内存地址0x60003000处，为什么是0x60000000起始的地址，参考文件u-boot的配置文件 include/configs/vexpress_common.h。如果用Qemu直接启动Kernel，是通过-append parameter 的方式给kernel传参的，现在是通过u-boot，那么需要通过u-boot的环境变量bootargs，可以设置为如下值 setenv bootargs 'root=/dev/mmcblk0 console=ttyAMA0 console=tty0'。 然后设置u-boot环境变量bootcmd，如下: setenv bootcmd 'tftp 0x60003000 uImage; bootm 0x60003000'.

具体步骤

1、启动Qemu的网络支持

这个请参考博客：http://www.cnblogs.com/pengdonglin137/p/5023340.html

2、配置u-boot

主要是修改include/configs/vexpress_common.h

diff --git a/include/configs/vexpress_common.h b/include/configs/vexpress_common.h
index 0c1da01..9fa7d9e
--- a/include/configs/vexpress_common.h
+++ b/include/configs/vexpress_common.h
@@ -, +, @@
 #define CONFIG_SYS_TEXT_BASE   0x80800000
 #endif

+/* netmask */
+#define CONFIG_IPADDR   192.168.11.5
+#define CONFIG_NETMASK  255.255.255.0
+#define CONFIG_SERVERIP 192.168.11.20
+
 /*
  * Physical addresses, offset from V2M_PA_CS0-3
  */
@@ -, +, @@
 #define CONFIG_SYS_INIT_SP_ADDR                CONFIG_SYS_GBL_DATA_OFFSET

 /* Basic environment settings */
-#define CONFIG_BOOTCOMMAND             "run bootflash;"
+/* #define CONFIG_BOOTCOMMAND          "run bootflash;" */
+#define CONFIG_BOOTCOMMAND             "tftp 0x60003000 uImage; setenv bootargs 'root=/dev/mmcblk0 console=ttyAMA0'; bootm 0x60003000
+

说明：

这里我把ipaddr等设置为了192.168.11.x网段，这个需要跟br0的网址一致，br0的地址在/etc/qemu-ifuo中修改：

#!/bin/sh

echo sudo tunctl -u $(id -un) -t $
sudo tunctl -u $(id -un) -t $

echo sudo ifconfig $ 0.0.0.0 promisc up
sudo ifconfig $ 0.0.0.0 promisc up

echo sudo brctl addif br0 $
sudo brctl addif br0 $

echo brctl show
brctl show

sudo ifconfig br0 192.168.11.20

然后重新编译u-boot代码

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- -j2

测试：

qemu-system-arm -M vexpress-a9 \
     -kernel u-boot \
     -nographic \
     -m 512M \
     -net nic,vlan= -net tap,vlan=,ifname=tap0

运行：

U-Boot 2015.07-rc3--gf3edfd3-dirty (Dec   - :: -)

DRAM:   MiB
WARNING: Caches not enabled
Flash:  MiB
MMC:   MMC:
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   smc911x-
Warning: smc911x- using MAC address from net device

Hit any key to stop autoboot:
VExpress# ping 192.168.11.20
smc911x: MAC :::::
smc911x: detected LAN9118 controller
smc911x: phy initialized
smc911x: MAC :::::
Using smc911x- device
smc911x: MAC :::::
host 192.168.11.20 is alive

2、配置Linux Kernel

因为要用u-boot引导，所以需要把Kernel编译成uImage格式。

执行如下命令：

make CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm O=./out_vexpress_3_16 uImage -j2

编译时会报错：

make[]: Entering directory `/root/tq2440_work/kernel/linux-stable/out_vexpress_3_16'
  CHK     include/config/kernel.release
  GEN     ./Makefile
  CHK     include/generated/uapi/linux/version.h
  Using .. as source for kernel
  CHK     include/generated/utsrelease.h
make[]: `include/generated/mach-types.h' is up to date.
  CALL    ../scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CHK     kernel/config_data.h
  Kernel: arch/arm/boot/Image is ready
  Kernel: arch/arm/boot/zImage is ready
multiple (or no) load addresses:
This is incompatible with uImages
Specify LOADADDR on the commandline to build an uImage
make[]: *** [arch/arm/boot/uImage] Error
make[]: *** [uImage] Error
make: *** [sub-make] Error 

这里需要我们制定LOADADDR的值，即uImage的加载地址，根据u-boot，我们可以将其设置为0x60003000.

修改后的命令如下：

make CROSS_COMPILE=arm-linux-gnueabi- ARCH=arm O=./out_vexpress_3_16 LOADADDR=0x60003000  uImage -j2

编译信息：

make[]: Entering directory `/root/tq2440_work/kernel/linux-stable/out_vexpress_3_16'
  CHK     include/config/kernel.release
  GEN     ./Makefile
  CHK     include/generated/uapi/linux/version.h
  Using .. as source for kernel
  CHK     include/generated/utsrelease.h
make[]: `include/generated/mach-types.h' is up to date.
  CALL    ../scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  CHK     kernel/config_data.h
  Kernel: arch/arm/boot/Image is ready
  Kernel: arch/arm/boot/zImage is ready
  UIMAGE  arch/arm/boot/uImage
Image Name:   Linux-3.16.
Created:      Sat Dec   ::
Image Type:   ARM Linux Kernel Image (uncompressed)
Data Size:     Bytes = 3248.73 kB = 3.17 MB
Load Address: 0x60003000
Entry Point:  0x60003000
  Image arch/arm/boot/uImage is ready

编译生成的uImage在 linux-stable/out_vexpress_3_16/arch/arm/boot下，然后将uImage拷贝到/tftpboot目录下，关于tftp服务器的配置请参考：
http://files.cnblogs.com/files/pengdonglin137/ubuntu-12.04%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91%E7%8E%AF%E5%A2%83%E6%90%AD%E5%BB%BA.pdf

3、测试

执行如下命令：

qemu-system-arm -M vexpress-a9 \
     -kernel /root/tq2440_work/u-boot/u-boot/u-boot \
     -nographic \
     -m 512M \
     -net nic,vlan= -net tap,vlan=,ifname=tap0 \
     -sd /root/tq2440_work/busybox_study/a9rootfs.ext3

启动信息：

sudo tunctl -u root -t tap0
sudo ifconfig tap0 0.0.0.0 promisc up
sudo brctl addif br0 tap0
brctl show
bridge name    bridge id        STP enabled    interfaces
br0        .000c290bd2f3    no        eth0
                            tap0

U-Boot 2015.07-rc3--gf3edfd3-dirty (Dec   - :: -)

DRAM:   MiB
WARNING: Caches not enabled
Flash:  MiB
MMC:   MMC:
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   smc911x-
Warning: smc911x- using MAC address from net device

Hit any key to stop autoboot:
smc911x: MAC :::::
smc911x: detected LAN9118 controller
smc911x: phy initialized
smc911x: MAC :::::
Using smc911x- device
TFTP from server 192.168.11.20; our IP address is 192.168.11.5
Filename 'uImage'.
Load address: 0x60003000
Loading: #################################################################
     #################################################################
     #################################################################
     ################################
     796.9 KiB/s
done
Bytes transferred =  (32c328 hex)
smc911x: MAC :::::
## Booting kernel from Legacy Image at  ...
   Image Name:   Linux-3.16.
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:     Bytes = 3.2 MiB
   Load Address:
   Entry Point:
   Verifying Checksum ... OK
   Loading Kernel Image ... OK

Starting kernel ...

Booting Linux on physical CPU 0x0
Initializing cgroup subsys cpuset
Linux version 3.16. (root@ubuntu) (gcc version 4.7. (Ubuntu/Linaro 4.7.-12ubuntu1) ) # SMP Sat Dec  :: PST
CPU: ARMv7 Processor [410fc090] revision  (ARMv7), cr=10c53c7d
CPU: PIPT / VIPT nonaliasing data cache, VIPT nonaliasing instruction cache
Machine: ARM-Versatile Express
Memory policy: Data cache writeback
CPU: All CPU(s) started in SVC mode.
sched_clock:  bits at 24MHz, resolution 41ns, wraps every 178956969942ns
PERCPU: Embedded  pages/cpu @9fbed000 s7552 r8192 d12928 u32768
Built  zonelists in Zone order, mobility grouping on.  Total pages:
Kernel command line: root=/dev/mmcblk0 console=ttyAMA0
PID hash table entries:  (order: ,  bytes)
Dentry cache hash table entries:  (order: ,  bytes)
Inode-cache hash table entries:  (order: ,  bytes)
Memory: 513272K/524288K available (4563K kernel code, 190K rwdata, 1292K rodata, 239K init, 149K bss, 11016K reserved)
Virtual kernel memory layout:
    vector  : 0xffff0000 - 0xffff1000   (    kB)
    fixmap  : 0xffc00000 - 0xffe00000   ( kB)
    vmalloc : 0xa0800000 - 0xff000000   ( MB)
    lowmem  : 0x80000000 - 0xa0000000   (  MB)
    modules : 0x7f000000 - 0x80000000   (   MB)
      .text : 0x80008000 - 0x805c01b0   ( kB)
      .init : 0x805c1000 - 0x805fcd80   (  kB)
      .data : 0x805fe000 - 0x8062dba0   (  kB)
       .bss : 0x8062dba8 - 0x8065336c   (  kB)
SLUB: HWalign=, Order=-, MinObjects=, CPUs=, Nodes=
Hierarchical RCU implementation.
    RCU restricting CPUs from NR_CPUS= to nr_cpu_ids=.
RCU: Adjusting geometry for rcu_fanout_leaf=, nr_cpu_ids=
NR_IRQS: nr_irqs:
GIC CPU mask not found - kernel will fail to boot.
GIC CPU mask not found - kernel will fail to boot.
smp_twd: clock not found -
Console: colour dummy device 80x30
Calibrating local timer... .21MHz.
Calibrating delay loop... 310.68 BogoMIPS (lpj=)
pid_max: default:  minimum:
Mount-cache hash table entries:  (order: ,  bytes)
Mountpoint-cache hash table entries:  (order: ,  bytes)
CPU: Testing write buffer coherency: ok
missing device node for CPU
CPU0: thread -, cpu , socket , mpidr
Setting up static identity map for 0x604546d0 - 0x60454728
Brought up  CPUs
SMP: Total of  processors activated.
CPU: All CPU(s) started in SVC mode.
devtmpfs: initialized
VFP support v0.: implementor  architecture  part  variant  rev
regulator-dummy: no parameters
NET: Registered protocol family
DMA: preallocated  KiB pool for atomic coherent allocations
cpuidle: using governor ladder
cpuidle: using governor menu
hw-breakpoint: debug architecture 0x4 unsupported.
Serial: AMBA PL011 UART driver
mb:uart0: ttyAMA0 at MMIO 0x10009000 (irq = , base_baud = ) is a PL011 rev1
console [ttyAMA0] enabled
mb:uart1: ttyAMA1 at MMIO 0x1000a000 (irq = , base_baud = ) is a PL011 rev1
mb:uart2: ttyAMA2 at MMIO 0x1000b000 (irq = , base_baud = ) is a PL011 rev1
mb:uart3: ttyAMA3 at MMIO 0x1000c000 (irq = , base_baud = ) is a PL011 rev1
fixed-dummy: no parameters
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
Advanced Linux Sound Architecture Driver Initialized.
Switched to clocksource v2m-timer1
NET: Registered protocol family
TCP established hash table entries:  (order: ,  bytes)
TCP bind hash table entries:  (order: ,  bytes)
TCP: Hash tables configured (established  bind )
TCP: reno registered
UDP hash table entries:  (order: ,  bytes)
UDP-Lite hash table entries:  (order: ,  bytes)
NET: Registered protocol family
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4. backchannel transport module.
CPU PMU: probing PMU on CPU
hw perfevents: enabled with ARMv7 Cortex-A9 PMU driver,  counters available
futex hash table entries:  (order: ,  bytes)
squashfs: version 4.0 (//) Phillip Lougher
jffs2: version 2.2. (NAND) © - Red Hat, Inc.
9p: Installing v9fs 9p2000 file system support
msgmni has been set to
io scheduler noop registered (default)
clcd-pl11x ct:clcd: PL111 rev2 at 0x10020000
clcd-pl11x ct:clcd: CT-CA9X4 hardware, XVGA display
Console: switching to colour frame buffer device 128x48
physmap platform flash device:  at
physmap-flash: Found  x16 devices at 0x0 in -bit bank. Manufacturer ID 0x000000 Chip ID 0x000000
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
physmap platform flash device:  at
physmap-flash: Found  x16 devices at 0x0 in -bit bank. Manufacturer ID 0x000000 Chip ID 0x000000
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
Concatenating MTD devices:
(): "physmap-flash"
(): "physmap-flash"
into device "physmap-flash"
libphy: smsc911x-mdio: probed
smsc911x smsc911x eth0: attached PHY driver [Generic PHY] (mii_bus:phy_addr=smsc911x-fffffff:, irq=-)
smsc911x smsc911x eth0: MAC Address: :::::
isp1760 isp1760: NXP ISP1760 USB Host Controller
isp1760 isp1760: new USB bus registered, assigned bus number
isp1760 isp1760: Scratch test failed.
isp1760 isp1760: can't setup: -19
isp1760 isp1760: USB bus  deregistered
isp1760: Failed to register the HCD device
usbcore: registered new interface driver usb-storage
mousedev: PS/ mouse device common for all mice
rtc-pl031 mb:rtc: rtc core: registered pl031 as rtc0
mmci-pl18x mb:mmci: mmc0: PL181 manf  rev0 at 0x10005000 irq , (pio)
input: AT Raw Set  keyboard as /devices/mb:kmi0/serio0/input/input0
ledtrig-cpu: registered to indicate activity on CPUs
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
mmc0: host does not support reading read-only switch. assuming write-enable.
mmc0: new SD card at address
mmcblk0: mmc0: QEMU! 32.0 MiB
 mmcblk0: unknown partition table
aaci-pl041 mb:aaci: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 43
aaci-pl041 mb:aaci: FIFO  entries
oprofile: using arm/armv7-ca9
TCP: cubic registered
NET: Registered protocol family
9pnet: Installing 9P2000 support
rtc-pl031 mb:rtc: setting system clock to -- :: UTC ()
ALSA device list:
  #: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 43
input: ImExPS/ Generic Explorer Mouse as /devices/mb:kmi1/serio1/input/input2
kjournald starting.  Commit interval  seconds
EXT3-fs (mmcblk0): using internal journal
EXT3-fs (mmcblk0): recovery complete
EXT3-fs (mmcblk0): mounted filesystem with writeback data mode
VFS: Mounted root (ext3 filesystem) on device :.
Freeing unused kernel memory: 236K (805c1000 - 805fc000)
random: nonblocking pool is initialized
mount: mounting none on /proc/bus/usb failed: No such file or directory

Please press Enter to activate this console. 

[root@vexpress ]#
[root@vexpress ]#
[root@vexpress ]#
[root@vexpress ]#
[root@vexpress ]#
[root@vexpress ]# ls
bin         etc         linuxrc     mnt         root        sys         usr
dev         lib         lost+found  proc        sbin        tmp         var
[root@vexpress ]# ifconfig
lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:  Metric:
          RX packets: errors: dropped: overruns: frame:
          TX packets: errors: dropped: overruns: carrier:
          collisions: txqueuelen:
          RX bytes: (0.0 B)  TX bytes: (0.0 B)

[root@vexpress ]# ifconfig eth0 192.168.11.5
smsc911x smsc911x eth0: SMSC911x/921x identified at 0xa0a40000, IRQ:
[root@vexpress ]# ping 192.168.11.20
PING 192.168.11.20 (192.168.11.20):  data bytes
 bytes from 192.168.11.20: seq= ttl= time=20.928 ms
 bytes from 192.168.11.20: seq= ttl= time=1.250 ms
 bytes from 192.168.11.20: seq= ttl= time=0.573 ms
^C
--- 192.168.11.20 ping statistics ---
 packets transmitted,  packets received, % packet loss
round-trip min/avg/max = 0.573/7.583/20.928 ms
[root@vexpress ]# 

可以在/etc/init.d/rcS中设置eth0的ip地址为 ifconfig eth0 192.168.11.5

4、开启图形界面

修改u-boot的bootargs环境变量为：

setenv bootargs 'root=/dev/mmcblk0 console=ttyAMA0 console=tty0';

执行命令：

qemu-system-arm -M vexpress-a9 \
     -kernel /root/tq2440_work/u-boot/u-boot/u-boot \
     -nographic \
     -m 512M \
     -net nic,vlan= -net tap,vlan=,ifname=tap0 \
     -sd /root/tq2440_work/busybox_study/a9rootfs.ext3

截图：

未完待续。