[oe] Kernel boot problems
Bernard Mentink
Bernard_Mentink at trimble.com
Thu Jul 28 20:51:24 UTC 2011
Many thanks for that,
I had a look through the buffer and I see pretty much normal bootup text
... It just isn't coming out of the serial port ..
The only error I saw was the following:
-----------------------------------------
8030cf80: 00000000 00000001 3a534656 6e614320 ........VFS: Can
8030cf90: 20746f6e 6e65706f 6f6f7220 65642074 not open root de
8030cfa0: 65636976 6e282220 296c6c75 726f2022 vice "(null)" or
8030cfb0: 6b6e7520 6e776f6e 6f6c622d 32286b63 unknown-block(2
8030cfc0: 64646100 66663d72 66666666 303a6666 .addr=ffffffff:0
8030cfd0: 69202c31 2d3d7172 000a2931 20393830 1, irq=-1)..089
8030cfe0: 30373178 20000a29 30307830 63313938 x170).. 0x00891c
8030cff0: 2030000a 7830202d 65666666 30303030 ..0 - 0xfffe0000
8030d000: 28202020 36393820 29426b20 2020200a ( 896 kB).
8030d010: 414d4420 20202020 30203a20 63666678 DMA : 0xffc
8030d020: 30303030 202d2030 66667830 30303065 00000 - 0xffe000
8030d030: 20203030 20202820 4d203220 200a2942 00 ( 2 MB).
8030d040: 76202020 6c6c616d 3a20636f 63783020 vmalloc : 0xc
8030d050: 30303834 20303030 7830202d 30303466 4800000 - 0xf400
8030d060: 30303030 28202020 30363720 29424d20 0000 ( 760 MB)
8030d070: 2020200a 776f6c20 206d656d 30203a20 . lowmem : 0
8030d080: 30306378 30303030 202d2030 34637830 xc0000000 - 0xc4
8030d090: 30303030 20203030 20202820 4d203436 000000 ( 64 M
8030d0a0: 200a2942 6d202020 6c75646f 3a207365 B). modules :
8030d0b0: 62783020 30303066 20303030 7830202d 0xbf000000 - 0x
8030d0c0: 30303063 30303030 28202020 36312020 c0000000 ( 16
8030d0d0: 29424d20 2020200a 2e202020 74696e69 MB). .init
8030d0e0: 30203a20 30306378 30303830 202d2030 : 0xc0008000 -
8030d0f0: 30637830 30653130 20203030 20202820 0xc001e000 (
8030d100: 6b203838 200a2942 20202020 65742e20 88 kB). .te
8030d110: 3a207478 63783020 65313030 20303030 xt : 0xc001e000
8030d120: 7830202d 65323063 30303031 28202020 - 0xc02e1000 (
8030d130: 38323832 29426b20 2020200a 2e202020 2828 kB). .
8030d140: 61746164 30203a20 32306378 30303666 data : 0xc02f600
8030d150: 202d2030 30637830 36633033 20203065 0 - 0xc030c6e0
8030d160: 20202820 6b203039 000a2942 00000000 ( 90 kB)......
--------------------------------------------
A bit futher down the buffer I saw normal printout ..
______________________________________________
8030d380: 00000000 00000000 00000000 00000000 ................
8030d390: 00000000 00000000 00000000 4c3e353c ............<5>L
8030d3a0: 78756e69 72657620 6e6f6973 362e3220 inux version 2.6
8030d3b0: 2e36332e 62282031 746e656d 406b6e69 .36.1 (bmentink@
8030d3c0: 68637241 29786f42 63672820 65762063 ArchBox) (gcc ve
8030d3d0: 6f697372 2e34206e 20332e35 31313032 rsion 4.5.3 2011
8030d3e0: 31313330 72702820 6c657265 65736165 0311 (prerelease
8030d3f0: 47282029 20294343 31232029 45525020 ) (GCC) ) #1 PRE
8030d400: 54504d45 69724620 6c754a20 20393220 EMPT Fri Jul 29
8030d410: 303a3830 36313a31 535a4e20 30322054 08:01:16 NZST 20
8030d420: 3c0a3131 50433e34 41203a55 36764d52 11.<4>CPU: ARMv6
8030d430: 6d6f632d 69746170 20656c62 636f7270 -compatible proc
8030d440: 6f737365 345b2072 62373031 5d343633 essor [4107b364]
8030d450: 76657220 6f697369 2034206e 4d524128 revision 4 (ARM
8030d460: 45543676 202c294a 303d7263 33356330 v6TEJ), cr=00c53
8030d470: 0a663738 433e343c 203a5550 54504956 87f.<4>CPU: VIPT
8030d480: 6e6f6e20 61696c61 676e6973 74616420 nonaliasing dat
8030d490: 61632061 2c656863 50495620 6f6e2054 a cache, VIPT no
8030d4a0: 696c616e 6e697361 6e692067 75727473 naliasing instru
8030d4b0: 6f697463 6163206e 0a656863 4d3e343c ction cache.<4>M
8030d4c0: 69686361 203a656e 69676f4c 20445063 achine: LogicPD
8030d4d0: 584d2e69 53203133 3c0a4d4f 654d3e34 i.MX31 SOM.<4>Me
8030d4e0: 79726f6d 6c6f7020 3a796369 43434520 mory policy: ECC
8030d4f0: 73696420 656c6261 44202c64 20617461 disabled, Data
8030d500: 68636163 72772065 62657469 0a6b6361 cache writeback.
8030d510: 4f3e373c 6f6e206e 30206564 746f7420 <7>On node 0 tot
8030d520: 61706c61 3a736567 33363120 3c0a3438 alpages: 16384.<
8030d530: 72663e37 615f6565 5f616572 74696e69 7>free_area_init
8030d540: 646f6e5f 6e203a65 2065646f 70202c30 _node: node 0, p
8030d550: 74616467 33306320 64306330 6e202c38 gdat c030c0d8, n
8030d560: 5f65646f 5f6d656d 2070616d 32333063 ode_mem_map c032
8030d570: 30303031 3e373c0a 6f4e2020 6c616d72 1000.<7> Normal
8030d580: 6e6f7a20 31203a65 70203832 73656761 zone: 128 pages
8030d590: 65737520 6f662064 656d2072 70616d6d used for memmap
8030d5a0: 3e373c0a 6f4e2020 6c616d72 6e6f7a20 .<7> Normal zon
8030d5b0: 30203a65 67617020 72207365 72657365 e: 0 pages reser
8030d5c0: 0a646576 203e373c 726f4e20 206c616d ved.<7> Normal
----------------------------------------------------------------------
I am not sure why it is not printing out the port, my boot param =
"console=ttymxc0,115200"
And the relevent part of conf/machine/mx31ads.conf = SERIAL_CONSOLE =
"115200 ttymxc0"
Any idea's?
Cheers,
Bernie
------------------------------------------------------------------------
------------------
I want to die peacefully in my sleep, like my grandfather, not screaming
and yelling like the passengers in his car.
-----Original Message-----
From: Gary Thomas [mailto:gary at mlbassoc.com]
Sent: Thursday, 28 July 2011 11:22 p.m.
To: openembedded-devel at lists.openembedded.org
Cc: Bernard Mentink
Subject: Re: [oe] Kernel boot problems
On 2011-07-27 20:20, Bernard Mentink wrote:
>
> Hi Guys,
>
> I have got a bit further with my efforts to boot linux on an imx31
> based platform using u-boot.
>
> My console output is now:
>
> ----------------------------------------------------------------
> uboot> bootm 80100000
> ## Booting kernel from Legacy Image at 80100000 ...
> Image Name: Angstrom/2.6.36/mx31ads
> Created: 2011-07-28 2:03:27 UTC
> Image Type: ARM Linux Kernel Image (uncompressed)
> Data Size: 1586172 Bytes = 1.5 MiB
> Load Address: 8f000000
> Entry Point: 8f000000
> Verifying Checksum ... OK
> Loading Kernel Image ... OK
> OK
>
> Starting kernel ...
>
> Uncompressing Linux... done, booting the kernel.
> -------------------------------------------------------------------
>
> So it seems to be getting to the 1st part of the kernel boot process,
> then hangs (I presume the last line comes from kernel code.) I don't
> know if the kernel is hanging, or if I don't have any more serial out
> ....
> I am passing "console=ttymxc0,115200" to the kernel ..
> Can someone confirm:
> A) If I have the correct Entry point, or does this need to be offset
> into the kernel? ..
> B) Is the serial console parameters correct?
> C) What is the correct way to set up the memory map? (my ram starts at
> 0x80000000, ends at 0x8fffffff)
> D) Is there a way to debug initial kernel stuff with serial output?
> In the above, I have decompressed the kernel to the top of the 256M
ram,
> but have only advertised 120M via the bootloader ... for now, not
> knowing what is correct and not wanting the kernel to stomp all over
> itself running in ram.
Analyzing this failure can be hard. If you have some sort of JTAG setup
you might be able to break in at this point, figure out where it's
hanging up, etc.
Even if you don't have JTAG, there might be some crumbs left around for
you to look at. Linux keeps everything that goes to the "console" in a
circular buffer __log_buf[]. Look up that symbol in System.map (which
will be found in your linux build tree). Here's the tricky part - the
map will show a logical address, but U-Boot only knows physical
addresses.
Normally the mapping is pretty easy, e.g. on my OMAP/3530 I might see:
$ grep __log_buf linux-2.6.37/System.map
c0527058 b __log_buf
So in U-Boot, I would look at the buffer like this:
U-Boot> md 0x80527058
80527058: 4c3e353c 78756e69 72657620 6e6f6973 <5>Linux version
80527068: 362e3220 2e37332e 67282033 6d6f6874 2.6.37.3 (gthom
80527078: 74407361 6e617469 67282029 76206363 as at titan) (gcc v
80527088: 69737265 34206e6f 312e362e 31303220 ersion 4.6.1 201
80527098: 32363031 70282037 65726572 7361656c 10627 (prereleas
805270a8: 28202965 29434347 23202920 72462031 e) (GCC) ) #1 Fr
805270b8: 754a2069 3232206c 3a393020 303a3135 i Jul 22 09:51:0
...
Keep looking through this buffer until it stops with useful characters.
That may tell you where the kernel got hung up and why. If you find
only garbage, it may be more difficult to tell.
Note: hopefully your board has a RESET button which you can use to get
back into U-Boot once the kernel boot process hangs. Power cycling to
reset the board won't work as the contents of RAM will likely be
destroyed.
--
------------------------------------------------------------
Gary Thomas | Consulting for the
MLB Associates | Embedded world
------------------------------------------------------------
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