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前面从uboot启动了内核和文件系统，但是步骤有点多，特别是进uboot之后，都要手动设置一次bootargs
简化一下这个步骤，从代码里面设置好这个内容
打开uboot下源码include/configs/vexpress_ca9x4.h
增加代码
#define CONFIG_BOOTCOMMAND "load mmc 0:1 0x60008000 zImage;"\
"load mmc 0:1 0x61000000 vexpress-v2p-ca9.dtb;"\
"setenv bootargs 'root=/dev/mmcblk0p2 rw rootfstype=ext4 rootwait earlycon console=ttyAMA0 init=/linuxrc ignore_loglevel';"\
"bootz 0x60008000 - 0x61000000;"重新编译
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j8
重新启动qemu
qemu-system-arm -M vexpress-a9 -m 512M -smp 1 -nographic -kernel ${uboot_image} -sd ./uboot.disk
下面是终端打印信息
U-Boot 2019.10-dirty (Jun 06 2021 - 16:17:33 +0800)
DRAM: 512 MiB
WARNING: Caches not enabled
Flash: 128 MiB
MMC: MMC: 0
*** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial
Net: smc911x-0
Hit any key to stop autoboot: 0
4882904 bytes read in 998 ms (4.7 MiB/s)
14163 bytes read in 47 ms (293.9 KiB/s)
Kernel image @ 0x60008000 [ 0x000000 - 0x4a81d8 ]
## Flattened Device Tree blob at 61000000
Booting using the fdt blob at 0x61000000
Loading Device Tree to 7fe82000, end 7fe88752 ... OK
Starting kernel ...
Booting Linux on physical CPU 0x0
Linux version 5.10.7 (jun@jun-virtual-machine) (arm-linux-gnueabihf-gcc (GCC) 10.2.1 20210407 [releases/gcc-10 revision bab1d20e09d385f2b92d066cd11971e200b0a18a], GNU ld (Linaro_Binutils-2021.04) 2.35.2.20210110) #1 SMP Sun Jun 6 13:22:44 CST 2021
CPU: ARMv7 Processor [410fc090] revision 0 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, VIPT nonaliasing instruction cache
OF: fdt: Machine model: V2P-CA9
OF: fdt: Ignoring memory block 0x80000000 - 0x80000004
Malformed early option 'earlycon'
printk: debug: ignoring loglevel setting.
Memory policy: Data cache writeback
Reserved memory: created DMA memory pool at 0x4c000000, size 8 MiB
OF: reserved mem: initialized node vram@4c000000, compatible id shared-dma-pool
cma: Reserved 16 MiB at 0x7ec00000
Zone ranges:
Normal [mem 0x0000000060000000-0x000000007fffffff]
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000060000000-0x000000007fffffff]
Initmem setup node 0 [mem 0x0000000060000000-0x000000007fffffff]
On node 0 totalpages: 131072
Normal zone: 1024 pages used for memmap
Normal zone: 0 pages reserved
Normal zone: 131072 pages, LIFO batch:31
CPU: All CPU(s) started in SVC mode.
percpu: Embedded 19 pages/cpu s46156 r8192 d23476 u77824
pcpu-alloc: s46156 r8192 d23476 u77824 alloc=19*4096
pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3
Built 1 zonelists, mobility grouping on. Total pages: 130048
Kernel command line: root=/dev/mmcblk0p2 rw rootfstype=ext4 rootwait earlycon console=ttyAMA0 init=/linuxrc ignore_loglevel
printk: log_buf_len individual max cpu contribution: 4096 bytes
printk: log_buf_len total cpu_extra contributions: 12288 bytes
printk: log_buf_len min size: 16384 bytes
printk: log_buf_len: 32768 bytes
printk: early log buf free: 14516(88%)
Dentry cache hash table entries: 65536 (order: 6, 262144 bytes, linear)
Inode-cache hash table entries: 32768 (order: 5, 131072 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 490828K/524288K available (8192K kernel code, 584K rwdata, 1712K rodata, 1024K init, 184K bss, 17076K reserved, 16384K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
rcu: Hierarchical RCU implementation.
rcu: RCU event tracing is enabled.
rcu: RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=4.
rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
GIC CPU mask not found - kernel will fail to boot.
GIC CPU mask not found - kernel will fail to boot.
L2C: platform modifies aux control register: 0x02020000 -> 0x02420000
L2C: DT/platform modifies aux control register: 0x02020000 -> 0x02420000
L2C-310 enabling early BRESP for Cortex-A9
L2C-310 full line of zeros enabled for Cortex-A9
L2C-310 dynamic clock gating disabled, standby mode disabled
L2C-310 cache controller enabled, 8 ways, 128 kB
L2C-310: CACHE_ID 0x410000c8, AUX_CTRL 0x46420001
random: get_random_bytes called from start_kernel+0x380/0x538 with crng_init=0
sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 89478484971ns
clocksource: arm,sp804: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911260446275 ns
Failed to initialize '/bus@4000000/motherboard/iofpga@7,00000000/timer@12000': -22
smp_twd: clock not found -2
Console: colour dummy device 80x30
Calibrating local timer... 92.78MHz.
Calibrating delay loop... 950.27 BogoMIPS (lpj=4751360)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
CPU: Testing write buffer coherency: ok
CPU0: Spectre v2: using BPIALL workaround
CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
Setting up static identity map for 0x60100000 - 0x60100060
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...
smp: Brought up 1 node, 1 CPU
SMP: Total of 1 processors activated (950.27 BogoMIPS).
CPU: All CPU(s) started in SVC mode.
devtmpfs: initialized
VFP support v0.3: implementor 41 architecture 3 part 30 variant 9 rev 0
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
futex hash table entries: 1024 (order: 4, 65536 bytes, linear)
NET: Registered protocol family 16
DMA: preallocated 256 KiB pool for atomic coherent allocations
cpuidle: using governor ladder
hw-breakpoint: debug architecture 0x4 unsupported.
Serial: AMBA PL011 UART driver
SCSI subsystem initialized
libata version 3.00 loaded.
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
Advanced Linux Sound Architecture Driver Initialized.
clocksource: Switched to clocksource arm,sp804
NET: Registered protocol family 2
tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 6144 bytes, linear)
TCP established hash table entries: 4096 (order: 2, 16384 bytes, linear)
TCP bind hash table entries: 4096 (order: 3, 32768 bytes, linear)
TCP: Hash tables configured (established 4096 bind 4096)
UDP hash table entries: 256 (order: 1, 8192 bytes, linear)
UDP-Lite hash table entries: 256 (order: 1, 8192 bytes, linear)
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.
hw perfevents: enabled with armv7_cortex_a9 PMU driver, 5 counters available
workingset: timestamp_bits=30 max_order=17 bucket_order=0
squashfs: version 4.0 (2009/01/31) Phillip Lougher
jffs2: version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
9p: Installing v9fs 9p2000 file system support
io scheduler mq-deadline registered
io scheduler kyber registered
i2c i2c-0: Added multiplexed i2c bus 2
physmap-flash 40000000.flash: physmap platform flash device: [mem 0x40000000-0x43ffffff]
40000000.flash: Found 2 x16 devices at 0x0 in 32-bit bank. Manufacturer ID 0x000000 Chip ID 0x000000
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
erase region 0: offset=0x0,size=0x40000,blocks=256
physmap-flash 40000000.flash: physmap platform flash device: [mem 0x44000000-0x47ffffff]
40000000.flash: Found 2 x16 devices at 0x0 in 32-bit bank. Manufacturer ID 0x000000 Chip ID 0x000000
Intel/Sharp Extended Query Table at 0x0031
Using buffer write method
erase region 0: offset=0x0,size=0x40000,blocks=256
Concatenating MTD devices:
(0): "40000000.flash"
(1): "40000000.flash"
into device "40000000.flash"
physmap-flash 48000000.psram: physmap platform flash device: [mem 0x48000000-0x49ffffff]
libphy: Fixed MDIO Bus: probed
libphy: smsc911x-mdio: probed
smsc911x 4e000000.ethernet eth0: MAC Address: 52:54:00:12:34:56
isp1760 4f000000.usb: bus width: 32, oc: digital
isp1760 4f000000.usb: NXP ISP1760 USB Host Controller
isp1760 4f000000.usb: new USB bus registered, assigned bus number 1
isp1760 4f000000.usb: Scratch test failed.
isp1760 4f000000.usb: can't setup: -19
isp1760 4f000000.usb: USB bus 1 deregistered
usbcore: registered new interface driver usb-storage
ledtrig-cpu: registered to indicate activity on CPUs
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
NET: Registered protocol family 17
9pnet: Installing 9P2000 support
oprofile: using arm/armv7-ca9
Registering SWP/SWPB emulation handler
aaci-pl041 10004000.aaci: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 28
aaci-pl041 10004000.aaci: FIFO 512 entries
mmci-pl18x 10005000.mmci: Got CD GPIO
mmci-pl18x 10005000.mmci: Got WP GPIO
mmci-pl18x 10005000.mmci: mmc0: PL181 manf 41 rev0 at 0x10005000 irq 29,30 (pio)
10009000.uart: ttyAMA0 at MMIO 0x10009000 (irq = 33, base_baud = 0) is a PL011 rev1
printk: console [ttyAMA0] enabled
1000a000.uart: ttyAMA1 at MMIO 0x1000a000 (irq = 34, base_baud = 0) is a PL011 rev1
1000b000.uart: ttyAMA2 at MMIO 0x1000b000 (irq = 35, base_baud = 0) is a PL011 rev1
1000c000.uart: ttyAMA3 at MMIO 0x1000c000 (irq = 36, base_baud = 0) is a PL011 rev1
rtc-pl031 10017000.rtc: registered as rtc0
rtc-pl031 10017000.rtc: setting system clock to 2021-06-06T08:20:08 UTC (1622967608)
drm-clcd-pl111 1001f000.clcd: assigned reserved memory node vram@4c000000
drm-clcd-pl111 1001f000.clcd: using device-specific reserved memory
drm-clcd-pl111 1001f000.clcd: core tile graphics present
drm-clcd-pl111 1001f000.clcd: this device will be deactivated
drm-clcd-pl111 1001f000.clcd: Versatile Express init failed - -19
drm-clcd-pl111 10020000.clcd: DVI muxed to daughterboard 1 (core tile) CLCD
mmc0: new SD card at address 4567
mmcblk0: mmc0:4567 QEMU! 1.00 GiB
drm-clcd-pl111 10020000.clcd: initializing Versatile Express PL111
drm-clcd-pl111 10020000.clcd: found bridge on endpoint 0
drm-clcd-pl111 10020000.clcd: Using non-panel bridge
[drm] Initialized pl111 1.0.0 20170317 for 10020000.clcd on minor 0
input: AT Raw Set 2 keyboard as /devices/platform/bus@4000000/bus@4000000:motherboard/bus@4000000:motherboard:iofpga@7,00000000/10006000.kmi/serio0/input/input0
random: fast init done
mmcblk0: p1 p2
Console: switching to colour frame buffer device 128x48
drm-clcd-pl111 10020000.clcd: [drm] fb0: pl111drmfb frame buffer device
ALSA device list:
#0: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 28
input: ImExPS/2 Generic Explorer Mouse as /devices/platform/bus@4000000/bus@4000000:motherboard/bus@4000000:motherboard:iofpga@7,00000000/10007000.kmi/serio1/input/input2
EXT4-fs (mmcblk0p2): recovery complete
EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
VFS: Mounted root (ext4 filesystem) on device 179:2.
devtmpfs: mounted
Freeing unused kernel memory: 1024K
Run /linuxrc as init process
with arguments:
/linuxrc
with environment:
HOME=/
TERM=linux
random: crng init done
EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
Starting syslogd: OK
Starting klogd: OK
Running sysctl: OK
Initializing random number generator: OK
Saving random seed: OK
Starting network: Generic PHY 4e000000.ethernet-ffffffff:01: attached PHY driver [Generic PHY] (mii_bus:phy_addr=4e000000.ethernet-ffffffff:01, irq=POLL)
smsc911x 4e000000.ethernet eth0: SMSC911x/921x identified at 0xa08b0000, IRQ: 26
udhcpc: started, v1.33.0
udhcpc: sending discover
udhcpc: sending select for 10.0.2.15
udhcpc: lease of 10.0.2.15 obtained, lease time 86400
deleting routers
adding dns 10.0.2.3
OK
Welcome to Buildroot
jun login: root
Password:
# cd ..
# ls
THIS_IS_NOT_YOUR_ROOT_FILESYSTEM opt
bin proc
dev root
etc run
lib sbin
lib32 sys
linuxrc tmp
lost+found usr
media var
mnt
#