PRODUCT FAQs

MT7688/MT7628, openwrt starts the kernel panic, the problem is solved

Using sdk4.3, I found that there has been a problem with the sd card driver, and I have no clue. Change the op.
After compiling the MT7628 image according to the default configuration in the op, it is found that it cannot be mounted on the 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

How can I not find it? At first, there was no mtdblock5 sentence, and then two problems were found:
1. The uboot of MT7628 does not pass cmdargs to the kernel at all.
2. The dts file of the kernel does not have root=xxxx.
Just a simple sentence:
/target/linux/ramips/dts/mt7628an.dtsi
chosen {
bootargs = "console=ttyS0,57600";
};
Later increase =/dev/mtdblock5, the problem is solved.

Continue to see later what is the problem with the MTK MSDC driver?

After startup, the printed information is as follows:

1. U-Boot 1.1.3 (Sep 15 2014 - 10:02:31)
2.
3.Board: Ralink APSoC DRAM: 64 MB
4. relocate_code Pointer at: 83fb8000
5.********************************
6. Software System Reset Occurred
7.********************************
8.flash manufacture id: ef, device id 40 17
9. Find flash: W25Q64BV
10. raspi_read: from:40035 len:1
11.0x893
12.raspi_read: from:30000 len:1000
13.0x7deaa
14.raspi_read: from:30000 len:1000
15.0x7dea6
16.==============================================
17.Ralink UBoot Version: 4.3.S.0
18.--------------------------------------------
19.ASIC 7628_MP (Port5<->None)
20.DRAM component: 512 Mbits DDR, width 16
21.DRAM bus: 16 bit
22.Total memory: 64 MBytes
23.Flash component: SPI Flash
24. Date: Sep 15 2014 Time: 10:02:31
25.==============================================
26.icache: sets:512, ways:4, linesz:32,total:65536
27.dcache: sets:256, ways:4, linesz:32,total:32768
28.
29. ##### The CPU freq = 575 MHZ ####
30. estimate memory size =64 Mbytes
31. RESET MT7628
32.Please choose the operation:
33. 1: Load system code to SDRAM via TFTP.
34. 2: Load system code then write to Flash via TFTP.
35. 3: Boot system code via Flash (default).
36. 4: Entr boot command line interface.
37. 7: Load Boot Loader code then write to Flash via Serial.
38. 9: Load Boot Loader code then write to Flash via TFTP.
39.default: 3 0
40.  
41.3: System Boot system code via Flash.
42.## Booting image at bc050000 …
43.raspi_read: from:50000 len:40
44.0x1f9f
45. Image Name: MIPS OpenWrt Linux-3.18.7
46. ​​Image Type: MIPS Linux Kernel Image (lzma compressed)
47. Data Size: 1185261 Bytes = 1.1 MB
48. Load Address: 80000000
49. Entry Point: 80000000
50.raspi_read: from:50040 len:1215ed
51.0x8e51ad9
52. Verifying Checksum... OK
53. Uncompressing Kernel Image... OK
54.No initrd
55.## Transferring control to Linux (at address 80000000) …
56.## Giving linux memsize in MB, 64
57.
58.Starting kernel...
59.
60.[ 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
61.[ 0.000000] Board has DDR2
62.[ 0.000000] Analog PMU set to hw control
63.[ 0.000000] Digital PMU set to hw control
64.[ 0.000000] SoC Type: Ralink MT7628AN ver:1 eco:2
65.[ 0.000000] bootconsole [early0] enabled
66.[ 0.000000] CPU0 revision is: 00019655 (MIPS 24KEc)
67.[ 0.000000] MIPS: machine is Mediatek MT7628AN evaluation board
68.[ 0.000000] Determined physical RAM map:
69.[ 0.000000] memory: 02000000 @ 00000000 (usable)
70.[ 0.000000] Initrd not found or empty - disabling initrd
71.[ 0.000000] Zone ranges:
72.[ 0.000000] Normal [mem 0x00000000-0x01ffffff]
73.[ 0.000000] Movable zone start for each node
74.[ 0.000000] Early memory node ranges
75.[ 0.000000] node 0: [mem 0x00000000-0x01ffffff]
76.[ 0.000000] Initmem setup node 0 [mem 0x00000000-0x01ffffff]
77.[ 0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
78.[ 0.000000] Primary data cache 32kB, 4-way, PIPT, no aliases, linesize 32 bytes
79.[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 8128
80.[ 0.000000] Kernel command line: console=ttyS0,57600 root=/dev/mtdblock5 rootfstype=squashfs,jffs2
81.[ 0.000000] PID hash table entries: 128 (order: -3, 512 bytes)
82.[ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes)
83.[ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes)
84.[ 0.000000] Writing ErrCtl register=0006eb40
85.[ 0.000000] Readback ErrCtl register=0006eb40
86.[ 0.000000] Memory: 28760K