请教各位大神：
我参考移植手册，移植linux4.4版本时，系统一直卡在Freeing unused kernel memory，不知卡在什么地方，请大神分析分析。。
##### FriendlyARM BIOS 2.0 for 2440 #####
[x] format NAND FLASH for Linux
[v] Download vivi
[k] Download linux kernel
[y] Download root_yaffs image
[a] Absolute User Application
[n] Download Nboot for WinCE
[l] Download WinCE boot-logo
[w] Download WinCE NK.bin
[d] Download & Run
[z] Download zImage into RAM
[g] Boot linux from RAM
[f] Format the nand flash
Boot the system
[s] Set the boot parameters
Backup NAND Flash to HOST through USB(upload)
[r] Restore NAND Flash from HOST through USB
[q] Goto shell of vivi
Version: 1138-2K
Enter your selection: b
Copy linux kernel from 0x00060000 to 0x30008000, size = 0x00500000 ... pos = 5242880, good pos = 560000
done
zImage magic = 0x016f2818
Setup linux parameters at 0x30000100
linux command line is: "noinitrd root=/dev/mtdblock3 init=/linuxrc console=ttySAC0"
MACH_TYPE = 1999
NOW, Booting Linux......
Uncompressing Linux... done, booting the kernel.
Warning: Neither atags nor dtb found
s3c24xx_serial_console_setup: co=c0539bf4 (0), 115200
s3c24xx_serial_probe(c054a858) 0
s3c24xx_serial_probe: initialising port c0539c2c...
s3c24xx_serial_init_port: port=c0539c5c, platdev=c054a858
resource [mem 0x50000000-0x50003fff])
port: map=0x50000000, mem=f7000000, irq=74 (74,75), clock=1
s3c24xx_serial_probe: adding port
s3c24xx_serial_console_setup: co=c0539bf4 (0), 115200
s3c24xx_serial_console_setup: port=c0539c5c (0)
s3c24xx_serial_console_setup: baud 115200
udivslot = 54aa (div 7)
config: 8bits/char
setting ulcon to 00000003, brddiv to 26, udivslot 000054aa
uart: ulcon = 0x00000003, ucon = 0x00000bc5, ufcon = 0x00000051
Booting Linux on physical CPU 0x0
Linux version 4.4.19 (alex@alex-virtual-machine) (gcc version 4.8.3 20140320 (prerelease) (Sourcery CodeBench Lite 2014.05-29) ) #60 Sun Sep 11 11:45:01 CST 2016
CPU: ARM920T [41129200] revision 0 (ARMv4T), cr=c000717f
CPU: VIVT data cache, VIVT instruction cache
Machine: ALEX2440
Warning: Neither atags nor dtb found
Memory policy: Data cache writeback
CPU S3C2440A (id 0x32440001)
Built 1 zonelists in Zone order, mobility grouping off. Total pages: 4064
Kernel command line: noinitrd root=/dev/mtdblock3 rw init=/linuxrc console=ttySAC0,115200 console=tty0
alex:str=/linuxrc
PID hash table entries: 64 (order: -4, 256 bytes)
Dentry cache hash table entries: 2048 (order: 1, 8192 bytes)
Inode-cache hash table entries: 1024 (order: 0, 4096 bytes)
Memory: 10508K/16384K available (3944K kernel code, 169K rwdata, 1096K rodata, 172K init, 249K bss, 5876K reserved, 0K cma-reserved)
Virtual kernel memory layout:
vector : 0xffff0000 - 0xffff1000 ( 4 kB)
fixmap : 0xffc00000 - 0xfff00000 (3072 kB)
vmalloc : 0xc1800000 - 0xff800000 ( 992 MB)
lowmem : 0xc0000000 - 0xc1000000 ( 16 MB)
modules : 0xbf000000 - 0xc0000000 ( 16 MB)
.text : 0xc0008000 - 0xc04f43b8 (5041 kB)
.init : 0xc04f5000 - 0xc0520000 ( 172 kB)
.data : 0xc0520000 - 0xc054a580 ( 170 kB)
.bss : 0xc054a580 - 0xc0588b50 ( 250 kB)
SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
alex:after mm init!
alex:before trace init!
NR_IRQS:103
S3C2440: IRQ Support
irq: clearing pending status 00000003
irq: clearing pending status 00000002
sched_clock: 16 bits at 1012kHz, resolution 987ns, wraps every 32362962ns
clocksource: samsung_clocksource_timer: mask: 0xffff max_cycles: 0xffff, max_idle_ns: 28803037 ns
alex:after kmem cache init!
Console: colour dummy device 80x30
console [tty0] enabled
alex:after locking test!
Calibrating delay loop... 201.52 BogoMIPS (lpj=503808)
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
alex:after check bugs!
alex:after rest init!
alex:before kernel thread init!
alex:complete kthreads!
alex:in kernel init!
Setting up static identity map for 0x30008200 - 0x30008258
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 9556302231375000 ns
NET: Registered protocol family 16
DMA: preallocated 256 KiB pool for atomic coherent allocations
cpuidle: using governor ladder
cpuidle: using governor menu
S3C2440: Initialising architecture
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
s3c-i2c s3c2440-i2c.0: slave address 0x10
s3c-i2c s3c2440-i2c.0: bus frequency set to 98 KHz
s3c-i2c s3c2440-i2c.0: i2c-0: S3C I2C adapter
Advanced Linux Sound Architecture Driver Initialized.
clocksource: Switched to clocksource samsung_clocksource_timer
NET: Registered protocol family 2
TCP established hash table entries: 1024 (order: 0, 4096 bytes)
TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
TCP: Hash tables configured (established 1024 bind 1024)
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.
futex hash table entries: 256 (order: -1, 3072 bytes)
NFS: Registering the id_resolver key type
Key type id_resolver registered
Key type id_legacy registered
romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
Console: switching to colour frame buffer device 60x53
s3c2410-lcd s3c2410-lcd: fb0: s3c2410fb frame buffer device
s3c2440-uart.0: ttySAC0 at MMIO 0x50000000 (irq = 74, base_baud = 0) is a S3C2440
console [ttySAC0] enabled
s3c24xx_serial_probe(c0527eb0) 1
s3c24xx_serial_probe: initialising port c0539d5c...
s3c24xx_serial_init_port: port=c0539d8c, platdev=c0527eb0
resource [mem 0x50004000-0x50007fff])
port: map=0x50004000, mem=f7004000, irq=77 (77,78), clock=1
s3c24xx_serial_probe: adding port
s3c2440-uart.1: ttySAC1 at MMIO 0x50004000 (irq = 77, base_baud = 0) is a S3C2440
s3c24xx_serial_probe(c0527d38) 2
s3c24xx_serial_probe: initialising port c0539e8c...
s3c24xx_serial_init_port: port=c0539ebc, platdev=c0527d38
resource [mem 0x50008000-0x5000bfff])
port: map=0x50008000, mem=f7008000, irq=80 (80,81), clock=1
s3c24xx_serial_probe: adding port
s3c2440-uart.2: ttySAC2 at MMIO 0x50008000 (irq = 80, base_baud = 0) is a S3C2440
brd: module loaded
s3c24xx-nand s3c2440-nand: Tacls=3, 29ns Twrph0=7 69ns, Twrph1=3 29ns
s3c24xx-nand s3c2440-nand: NAND soft ECC
nand: device found, Manufacturer ID: 0xec, Chip ID: 0xd3
nand: Samsung NAND 1GiB 3,3V 8-bit
nand: 1024 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
Scanning device for bad blocks
Bad eraseblock 4321 at 0x000021c20000
Creating 5 MTD partitions on "NAND":
0x000000000000-0x000000040000 : "bootloader"
0x000000040000-0x000000060000 : "param"
0x000000060000-0x000000560000 : "Kernel"
0x000000560000-0x000040560000 : "root"
mtd: partition "root" extends beyond the end of device "NAND" -- size truncated to 0x3faa0000
0x000000000000-0x000040000000 : "nand"
eth0: dm9000e at c190c300,c190e304 IRQ 55 MAC: 08:90:90:90:90:90 (chip)
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci-s3c2410: OHCI S3C2410 driver
s3c2410-ohci s3c2410-ohci: OHCI Host Controller
s3c2410-ohci s3c2410-ohci: new USB bus registered, assigned bus number 1
s3c2410-ohci s3c2410-ohci: irq 42, io mem 0x49000000
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
mousedev: PS/2 mouse device common for all mice
i2c /dev entries driver
s3c2410-wdt s3c2410-wdt: watchdog inactive, reset disabled, irq disabled
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
hidraw: raw HID events driver (C) Jiri Kosina
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
NET: Registered protocol family 17
Key type dns_resolver registered
hctosys: unable to open rtc device (rtc0)
ALSA device list:
No soundcards found.
yaffs: dev is 32505859 name is "mtdblock3" rw
yaffs: passed flags ""
VFS: Mounted root (yaffs filesystem) on device 31:3.
Freeing unused kernel memory: 172K (c04f5000 - c0520000)
