MT7688/MT7628,openwrt启动 kernel panic，问题解决

前几天使用sdk4.3，发现sd卡驱动一直有问题，没头绪，换op。
op中按照默认配置编译出MT7628镜像后，发现无法挂在rootfs。
[    0.790000] VFS: Cannot open root device "mtdblock5" or unknown-block(31,5): error -2
[    0.810000] Please append a correct "root=" boot option; here are the available partitions:
[    0.830000] 1f00             192 mtdblock0  (driver?)
[    0.840000] 1f01              64 mtdblock1  (driver?)
[    0.850000] 1f02              64 mtdblock2  (driver?)
[    0.860000] 1f03            7872 mtdblock3  (driver?)
[    0.870000] 1f04            1157 mtdblock4  (driver?)
[    0.880000] 1f05            6714 mtdblock5  (driver?)
[    0.890000] 1f06            5248 mtdblock6  (driver?)
[    0.900000] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,5)
[    0.900000] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,5)
[   82.700000] random: nonblocking pool is initialized
                                  
怎么会找不到呢？起先甚至都没有mtdblock5 这一句，后来网上搜罗一番，发现两个问题：1、MT7628的uboot，根本没给kernel传递cmdargs。2、内核的dts文件，也没有root=xxxx。
只有简单的一句：
/target/linux/ramips/dts/mt7628an.dtsi               
chosen {
                bootargs = "console=ttyS0,57600";
        };
 
后来我果断增加=/dev/mtdblock5，问题解决。
                                                                                                                                         
稍后再继续看  MTK MSDC 驱动到底在闹什么鬼                                    
 启动后打印信息如下：

U-Boot 1.1.3 (Sep 15 2014 - 10:02:31)

Board: Ralink APSoC DRAM: 64 MB
relocate_code Pointer at: 83fb8000
******************************
Software System Reset Occurred
******************************
flash manufacture id: ef, device id 40 17
find flash: W25Q64BV
raspi_read: from:40035 len:1
0x893
raspi_read: from:30000 len:1000
0x7deaa
raspi_read: from:30000 len:1000
0x7dea6
============================================
Ralink UBoot Version: 4.3.S.0
--------------------------------------------
ASIC 7628_MP (Port5<->None)
DRAM component: 512 Mbits DDR, width 16
DRAM bus: 16 bit
Total memory: 64 MBytes
Flash component: SPI Flash
Date:Sep 15 2014 Time:10:02:31
============================================
icache: sets:512, ways:4, linesz:32 ,total:65536
dcache: sets:256, ways:4, linesz:32 ,total:32768

 ##### The CPU freq = 575 MHZ ####
 estimate memory size =64 Mbytes
RESET MT7628
Please choose the operation:
   1: Load system code to SDRAM via TFTP.
   2: Load system code then write to Flash via TFTP.
   3: Boot system code via Flash (default).
   4: Entr boot command line interface.
   7: Load Boot Loader code then write to Flash via Serial.
   9: Load Boot Loader code then write to Flash via TFTP.
default: 3                                                                               0

3: System Boot system code via Flash.
## Booting image at bc050000 ...
raspi_read: from:50000 len:40
0x1f9f
   Image Name: MIPS OpenWrt Linux-3.18.7
   Image Type: MIPS Linux Kernel Image (lzma compressed)
   Data Size: 1185261 Bytes = 1.1 MB
   Load Address: 80000000
   Entry Point: 80000000
raspi_read: from:50040 len:1215ed
0x8e51ad9
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK
No initrd
## Transferring control to Linux (at address 80000000) ...
## Giving linux memsize in MB, 64

Starting kernel ...

[ 0.000000] Linux version 3.18.7 (mango@mango-V) (gcc version 4.8.3 (OpenWrt/Linaro GCC 4.8-2014.04 r44581) ) #8 Wed Mar 4 09:42:31 EST 2015
[ 0.000000] Board has DDR2
[ 0.000000] Analog PMU set to hw control
[ 0.000000] Digital PMU set to hw control
[ 0.000000] SoC Type: Ralink MT7628AN ver:1 eco:2
[ 0.000000] bootconsole [early0] enabled
[ 0.000000] CPU0 revision is: 00019655 (MIPS 24KEc)
[ 0.000000] MIPS: machine is Mediatek MT7628AN evaluation board
[ 0.000000] Determined physical RAM map:
[ 0.000000] memory: 02000000 @ 00000000 (usable)
[ 0.000000] Initrd not found or empty - disabling initrd
[ 0.000000] Zone ranges:
[ 0.000000] Normal [mem 0x00000000-0x01ffffff]
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node   0: [mem 0x00000000-0x01ffffff]
[ 0.000000] Initmem setup node 0 [mem 0x00000000-0x01ffffff]
[ 0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
[ 0.000000] Primary data cache 32kB, 4-way, PIPT, no aliases, linesize 32 bytes
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 8128
[ 0.000000] Kernel command line: console=ttyS0,57600 root=/dev/mtdblock5 rootfstype=squashfs,jffs2
[ 0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
[ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
[ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.000000] Writing ErrCtl register=0006eb40
[ 0.000000] Readback ErrCtl register=0006eb40
[ 0.000000] Memory: 28760K/32768K available (2586K kernel code, 131K rwdata, 536K rodata, 192K init, 186K bss, 4008K reserved)
[ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[ 0.000000] NR_IRQS:256
[ 0.000000] intc: using register map from devicetree
[ 0.000000] CPU Clock: 580MHz
[ 0.000000] clocksource_of_init: no matching clocksources found
[ 0.000000] Calibrating delay loop... 385.84 BogoMIPS (lpj=1929216)
[ 0.060000] pid_max: default: 32768 minimum: 301
[ 0.060000] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.070000] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.080000] pinctrl core: initialized pinctrl subsystem
[ 0.090000] NET: Registered protocol family 16
[ 0.100000] rt2880-pinmux pinctrl: invalid group "jtag" for function "gpio"
[ 0.120000] mt7621_gpio 10000600.gpio: registering 32 gpios
[ 0.130000] mt7621_gpio 10000600.gpio: registering 32 gpios
[ 0.140000] mt7621_gpio 10000600.gpio: registering 32 gpios
[ 0.150000] Switched to clocksource MIPS
[ 0.160000] NET: Registered protocol family 2
[ 0.160000] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.180000] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.190000] TCP: Hash tables configured (established 1024 bind 1024)
[ 0.200000] TCP: reno registered
[ 0.210000] UDP hash table entries: 256 (order: 0, 4096 bytes)
[ 0.220000] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[ 0.230000] NET: Registered protocol family 1
[ 0.240000] futex hash table entries: 256 (order: -1, 3072 bytes)
[ 0.260000] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[ 0.270000] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
[ 0.300000] msgmni has been set to 56
[ 0.310000] io scheduler noop registered
[ 0.320000] io scheduler deadline registered (default)
[ 0.330000] drivers/phy/phy-ralink-usb.c:ralink_usb_phy_probe[147]
[ 0.340000] drivers/phy/phy-ralink-usb.c:ralink_usb_phy_probe[161]
[ 0.360000] Serial: 8250/16550 driver, 2 ports, IRQ sharing disabled
[ 0.370000] rt2880-pinmux pinctrl: invalid group "uart0" for function "uart"
[ 0.380000] console [ttyS0] disabled
[ 0.390000] 10000c00.uartlite: ttyS0 at MMIO 0x10000c00 (irq = 28, base_baud = 2500000) is a 16550A
[ 0.410000] console [ttyS0] enabled
[ 0.410000] console [ttyS0] enabled
[ 0.420000] bootconsole [early0] disabled
[ 0.420000] bootconsole [early0] disabled
[ 0.440000] m25p80 spi32766.0: found s25fl064k, expected en25q64
[ 0.450000] m25p80 spi32766.0: s25fl064k (8192 Kbytes)
[ 0.460000] m25p80 spi32766.0: using chunked io
[ 0.470000] 4 ofpart partitions found on MTD device spi32766.0
[ 0.490000] Creating 4 MTD partitions on "spi32766.0":
[ 0.500000] 0x000000000000-0x000000030000 : "u-boot"
[ 0.510000] 0x000000030000-0x000000040000 : "u-boot-env"
[ 0.520000] 0x000000040000-0x000000050000 : "factory"
[ 0.530000] 0x000000050000-0x000000800000 : "firmware"
[ 0.570000] 2 uimage-fw partitions found on MTD device firmware
[ 0.590000] 0x000000050000-0x00000017162d : "kernel"
[ 0.600000] mtd: partition "kernel" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only
[ 0.620000] 0x00000017162d-0x000000800000 : "rootfs"
[ 0.630000] mtd: partition "rootfs" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only
[ 0.660000] mtd: device 5 (rootfs) set to be root filesystem
[ 0.670000] 1 squashfs-split partitions found on MTD device rootfs
[ 0.680000] 0x0000002e0000-0x000000800000 : "rootfs_data"
[ 0.700000] ralink_soc_eth 10100000.ethernet eth0: ralink at 0xb0100000, irq 5
[ 0.720000] mt7621_wdt 10000120.watchdog: Initialized
[ 0.730000] MTK MSDC device init.
[ 0.730000] mtk-sd: MediaTek MT6575 MSDC Driver
[ 0.740000] TCP: cubic registered
[ 0.750000] NET: Registered protocol family 17
[ 0.760000] bridge: automatic filtering via arp/ip/ip6tables has been deprecated. Update your scripts to load br_netfilter if you need this.
[ 0.780000] 8021q: 802.1Q VLAN Support v1.8
[ 0.810000] VFS: Mounted root (squashfs filesystem) readonly on device 31:5.
[ 0.820000] Freeing unused kernel memory: 192K (80330000 - 80360000)
[ 2.610000] init: Console is alive
[ 2.620000] init: - watchdog -
[ 3.650000] usbcore: registered new interface driver usbfs
[ 3.660000] usbcore: registered new interface driver hub
[ 3.670000] usbcore: registered new device driver usb
[ 3.680000] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 3.700000] ehci-platform: EHCI generic platform driver
[ 3.910000] phy phy-usbphy.0: remote usb device wakeup disabled
[ 3.920000] phy phy-usbphy.0: UTMI 16bit 30MHz
[ 3.930000] ehci-platform 101c0000.ehci: EHCI Host Controller
[ 3.940000] ehci-platform 101c0000.ehci: new USB bus registered, assigned bus number 1
[ 3.960000] ehci-platform 101c0000.ehci: irq 26, io mem 0x101c0000
[ 3.990000] ehci-platform 101c0000.ehci: USB 2.0 started, EHCI 1.00
[ 4.000000] hub 1-0:1.0: USB hub found
[ 4.010000] hub 1-0:1.0: 1 port detected
[ 4.020000] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 4.030000] ohci-platform: OHCI generic platform driver
[ 4.040000] ohci-platform 101c1000.ohci: Generic Platform OHCI controller
[ 4.050000] ohci-platform 101c1000.ohci: new USB bus registered, assigned bus number 2
[ 4.070000] ohci-platform 101c1000.ohci: irq 26, io mem 0x101c1000
[ 4.140000] hub 2-0:1.0: USB hub found
[ 4.150000] hub 2-0:1.0: 1 port detected
[ 4.630000] init: - preinit -
[ 4.960000] rt305x-esw 10110000.esw: link changed 0x00
[ 5.140000] random: mktemp urandom read with 7 bits of entropy available
Press the [f] key and hit [enter] to enter failsafe mode
Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level
[ 8.010000] rt305x-esw 10110000.esw: link changed 0x01
[ 8.540000] jffs2: notice: (310) jffs2_build_xattr_subsystem: complete building xattr subsystem, 0 of xdatum (0 unchecked, 0 orphan) and 0 of xref (0 dead, 0 orphan) found.
[ 8.570000] mount_root: switching to jffs2 overlay
[ 8.610000] procd: - early -
[ 8.610000] procd: - watchdog -
[ 9.390000] procd: - ubus -
[ 10.410000] procd: - init -
Please press Enter to activate this console.
[ 11.010000] NET: Registered protocol family 10
[ 11.020000] ip6_tables: (C) 2000-2006 Netfilter Core Team
[ 11.050000] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 11.070000] nf_conntrack version 0.5.0 (452 buckets, 1808 max)
[ 11.120000] xt_time: kernel timezone is -0000
[ 11.140000] PPP generic driver version 2.4.2
[ 11.150000] NET: Registered protocol family 24
[ 13.960000] rt305x-esw 10110000.esw: link changed 0x00



BusyBox v1.22.1 (2015-03-01 08:16:00 EST) built-in shell (ash)
Enter 'help' for a list of built-in commands.

  _______                     ________        __
 | |.-----.-----.-----.| | | |.----.| |_
 | - || _ | -__| || | | || _|| _|
 |_______|| __|_____|__|__||________||__| |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 CHAOS CALMER (Bleeding Edge, r44581)
 -----------------------------------------------------
  * 1 1/2 oz Gin            Shake with a glassful
  * 1/4 oz Triple Sec       of broken ice and pour
  * 3/4 oz Lime Juice       unstrained into a goblet.
  * 1 1/2 oz Orange Juice
  * 1 tsp. Grenadine Syrup
 -----------------------------------------------------
root@OpenWrt:/# [ 15.710000] device eth0.1 entered promiscuous mode
[ 15.720000] device eth0 entered promiscuous mode
[ 15.770000] br-lan: port 1(eth0.1) entered forwarding state
[ 15.780000] br-lan: port 1(eth0.1) entered forwarding state
[ 17.030000] rt305x-esw 10110000.esw: link changed 0x01
[ 17.780000] br-lan: port 1(eth0.1) entered forwarding state
[ 78.990000] random: nonblocking pool is initialized

root@OpenWrt:/#
root@OpenWrt:/#