创建用于ARM的Linux uImage后，QEMU显示黑色屏幕

Question

所以我一直在关注这篇文章：

https://opensourceforu.com/2011/06/qemu-for-embedded-systems-development-part-1/

我首先确保在menuconfig中启用了“使用ARM EABI编译内核”选项，并将其保存为.config。

在此之后，我运行了以下命令并获得了以下输出：

ivan@UbuntuMATE:~/Programming/linux$ make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- uImage -s LOADADDR=0x00008000
<stdin>:1332:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp]
Image Name:   Linux-4.18.0-10986-g778a33959a8a
Created:      Mon Aug 20 23:09:46 2018
Image Type:   ARM Linux Kernel Image (uncompressed)
Data Size:    2816048 Bytes = 2750.05 kB = 2.69 MB
Load Address: 00008000
Entry Point:  00008000

现在，当我尝试使用以下命令测试映像时，就会出现问题：

ivan@UbuntuMATE:~/Programming/linux$ qemu-system-arm -M versatilepb -m 256M -kernel arch/arm/boot/uImage

我有个黑屏幕。我知道内核会崩溃，但我仍然希望看到屏幕上的文本。在阅读了与此类似的评论和几个问题之后，我尝试使用以下命令：

ivan@UbuntuMATE:~/Programming/linux$ qemu-system-arm -M versatilepb -m 256M -kernel arch/arm/boot/uImage -append "console=ttyAMA0"

我也尝试过使用tty1，甚至尝试过这个链接所暗示的内容：

Just black screen after running Qemu

请告知如何进行。提前感谢！

编辑：，我想出来了！！谢谢你@bornfree给我指引答案的起点！

低，看，我不再得到一个空白的屏幕，但我仍然有一个错误：

Error: invalid dtb and unrecognized/unsupported machine ID
  r1=0x00000183, r2=0x00000100
  r2[]=05 00 00 00 01 00 41 54 01 00 00 00 00 10 00 00 Available machine support:

ID (hex)    NAME
ffffffff    Generic DT based system
ffffffff    ARM-Versatile (Device Tree Support)

Please check your kernel config and/or bootloader.

因此，在做了一些研究之后，我了解到我的旧命令不能工作的原因是因为在过去，他们拥有内核中不同板的所有代码。所以他们决定把它分成设备树文件(我认为这就是你在上一封电子邮件中提到的？)因此，我注意到板文件包含在/arch/arm/dts文件夹中，但它们只是源文件。因此，我必须找到一种方法将板编译成一个dtb，以便能够使用-dtb将其包含到qemu中。一开始，我发现了以下命令：

ivan@UbuntuMATE-VBox:~/linux/scripts/dtc$ ./dtc -I dts -O dtb -o versatile-pb.dtb /home/ivan/linux/arch/arm/boot/dts/versatile-pb.dts
Error: /home/ivan/linux/arch/arm/boot/dts/versatile-pb.dts:2.1-2 syntax error FATAL ERROR: Unable to parse input tree

所以这有点令人沮丧，直到我发现有一种用make制作我需要的图像的方法。首先生成配置文件。

ivan@UbuntuMATE-VBox:~/linux$ make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- versatile_defconfig

然后生成dtb文件：

ivan@UbuntuMATE-VBox:~/linux$ make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- dtbs

(在继续之前，我应该提到，我构建了最初教程中提到的简单根文件系统。你会在下面看到我的意思。

然后我又试着运行命令：

qemu-system-arm -M versatilepb -m 256M -nographic -kernel /home/ivan/linux/arch/arm/boot/uImage -initrd /home/ivan/opt/test/rootfs -dtb dts/versatile-pb.dtb -append "root=/dev/ram rdinit=/hello console= ttyS0"

然后我得到了另一个错误：

vpb_sic_write: Bad register offset 0x2c

因此，我发现ttyS0模拟PC风格的8250/16550串口，其中QEMU使用AMBA PL011作为通用机器，所以它使用ttyAMA0，这是我最初测试的。既然我的台词变了，我想我该改了.

qemu-system-arm -M versatilepb -m 256M -nographic -kernel /home/ivan/linux/arch/arm/boot/uImage -initrd /home/ivan/opt/test/rootfs -dtb dts/versatile-pb.dtb -append "root=/dev/ram rdinit=/hello console= ttyAMA0"

Low和behold....it终于成功了！

vpb_sic_write: Bad register offset 0x2c
Booting Linux on physical CPU 0x0
Linux version 4.18.0+ (ivan@UbuntuMATE-VBox) (gcc version 7.3.0 (Ubuntu/Linaro 7.3.0-16ubuntu3)) #1 Tue Aug 21 15:56:30 PDT 2018
CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00093177
CPU: VIVT data cache, VIVT instruction cache
OF: fdt: Machine model: ARM Versatile PB Memory policy: Data cache writeback
random: get_random_bytes called from start_kernel+0x7c/0x3e4 with crng_init=0 Built 1 zonelists, mobility grouping on.  Total pages: 65024 Kernel command line: root=/dev/ram rdinit=/hello console=ttyAMA0 Dentry cache hash table entries: 32768 (order: 5, 131072 bytes) Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 253796K/262144K available (3935K kernel code, 144K rwdata, 964K rodata, 176K init, 130K bss, 8348K reserved, 0K cma-reserved) Virtual kernel memory layout:
    vector  : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
    vmalloc : 0xd0800000 - 0xff800000   ( 752 MB)
    lowmem  : 0xc0000000 - 0xd0000000   ( 256 MB)
    modules : 0xbf000000 - 0xc0000000   (  16 MB)
      .text : 0x(ptrval) - 0x(ptrval)   (3937 kB)
      .init : 0x(ptrval) - 0x(ptrval)   ( 176 kB)
      .data : 0x(ptrval) - 0x(ptrval)   ( 145 kB)
       .bss : 0x(ptrval) - 0x(ptrval)   ( 131 kB)
NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16 VIC @(ptrval): id 0x00041190, vendor 0x41 FPGA IRQ chip 0 "intc" @ (ptrval), 20 irqs, parent IRQ: 47
clocksource: arm,sp804: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911260446275 ns
sched_clock: 32 bits at 1000kHz, resolution 1000ns, wraps every 2147483647500ns Failed to initialize '/amba/timer@101e3000': -22
sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 89478484971ns
Console: colour dummy device 80x30
Calibrating delay loop... 290.20 BogoMIPS (lpj=1451008)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes) Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
CPU: Testing write buffer coherency: ok
Setting up static identity map for 0x8400 - 0x8458 VFP support v0.3: implementor 41 architecture 1 part 10 variant 9 rev 0
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns futex hash table entries: 256 (order: -1, 3072 bytes)
NET: Registered protocol family 16
DMA: preallocated 256 KiB pool for atomic coherent allocations
OF: amba_device_add() failed (-19) for /amba/smc@10100000
OF: amba_device_add() failed (-19) for /amba/mpmc@10110000
OF: amba_device_add() failed (-19) for /amba/sctl@101e0000
OF: amba_device_add() failed (-19) for /amba/watchdog@101e1000
OF: amba_device_add() failed (-19) for /amba/sci@101f0000
OF: amba_device_add() failed (-19) for /amba/ssp@101f4000
OF: amba_device_add() failed (-19) for /amba/fpga/sci@a000
Serial: AMBA PL011 UART driver
101f1000.uart: ttyAMA0 at MMIO 0x101f1000 (irq = 28, base_baud = 0) is a PL011 rev1 console [ttyAMA0] enabled
101f2000.uart: ttyAMA1 at MMIO 0x101f2000 (irq = 29, base_baud = 0) is a PL011 rev1
101f3000.uart: ttyAMA2 at MMIO 0x101f3000 (irq = 30, base_baud = 0) is a PL011 rev1
uart-pl011 10009000.uart: aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.
10009000.uart: ttyAMA3 at MMIO 0x10009000 (irq = 54, base_baud = 0) is a PL011 rev1
clocksource: Switched to clocksource arm,sp804
NET: Registered protocol family 2
tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 4096 bytes) TCP established hash table entries: 2048 (order: 1, 8192 bytes) TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048) UDP hash table entries: 256 (order: 0, 4096 bytes) UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
NET: Registered protocol family 1
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
Trying to unpack rootfs image as initramfs...
Freeing initrd memory: 492K
NetWinder Floating Point Emulator V0.97 (double precision)
workingset: timestamp_bits=30 max_order=16 bucket_order=0 Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
jffs2: version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 252) io scheduler noop registered io scheduler deadline registered io scheduler cfq registered (default) io scheduler mq-deadline registered io scheduler kyber registered pl061_gpio 101e4000.gpio: PL061 GPIO chip @0x101e4000 registered pl061_gpio 101e5000.gpio: PL061 GPIO chip @0x101e5000 registered pl061_gpio 101e6000.gpio: PL061 GPIO chip @0x101e6000 registered pl061_gpio 101e7000.gpio: PL061 GPIO chip @0x101e7000 registered versatile-tft-panel 10000000.sysreg:display@0: no panel detected
drm-clcd-pl111 dev:20: set up callbacks for Versatile PL110
brd: module loaded
of-flash 34000000.flash: versatile/realview flash protection
34000000.flash: Found 1 x32 devices at 0x0 in 32-bit bank. Manufacturer ID 0x000000 Chip ID 0x000000 Intel/Sharp Extended Query Table at 0x0031 Using buffer write method
smc91x.c: v1.1, sep 22 2004 by Nicolas Pitre <nico@fluxnic.net> smc91x 10010000.net eth0: SMC91C11xFD (rev 1) at (ptrval) IRQ 41 smc91x 10010000.net eth0: Ethernet addr: 52:54:00:12:34:56
rtc-ds1307 0-0068: registered as rtc0
versatile reboot driver registered
mmci-pl18x fpga:05: mmc0: PL181 manf 41 rev0 at 0x10005000 irq 59,60 (pio) mmci-pl18x fpga:0b: mmc1: PL181 manf 41 rev0 at 0x1000b000 irq 49,50 (pio) leds-syscon 10000000.core-module:led@08.0: registered LED versatile:0 leds-syscon 10000000.core-module:led@08.1: registered LED versatile:1 leds-syscon 10000000.core-module:led@08.2: registered LED versatile:2 leds-syscon 10000000.core-module:led@08.3: registered LED versatile:3 leds-syscon 10000000.core-module:led@08.4: registered LED versatile:4 leds-syscon 10000000.core-module:led@08.5: registered LED versatile:5 leds-syscon 10000000.core-module:led@08.6: registered LED versatile:6 leds-syscon 10000000.core-module:led@08.7: registered LED versatile:7
ledtrig-cpu: registered to indicate activity on CPUs
NET: Registered protocol family 17
input: AT Raw Set 2 keyboard as /devices/platform/amba/amba:fpga/10006000.kmi/serio0/input/input0
drm-clcd-pl111 dev:20: set up callbacks for Versatile PL110
drm-clcd-pl111 dev:20: set up callbacks for Versatile PL110
rtc-ds1307 0-0068: setting system clock to 2018-08-22 23:24:34 UTC (1534980274) Freeing unused kernel memory: 176K This architecture does not have kernel memory protection.
Hello World!random: fast init done
input: ImExPS/2 Generic Explorer Mouse as /devices/platform/amba/amba:fpga/10007000.kmi/serio1/input/input2
drm-clcd-pl111 dev:20: set up callbacks for Versatile PL110

Hello World!
Hello World!

Answer 1

尝试使用以下命令。

qemu-arm系统-M -m 256 m -nographic -kernel arch/arm/boot/uImage -append "console=ttyS0“