NewBie: Using qemu-omap3 from maemo

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1

Hello.

I want to build a microkernel+app on the beagleboard and on an emulator.

So far I tried creating a .bin which I can:
- upload and test on my real beagleboard (and it works)
- load it into the qemu-system-arm -M beagle -mtdblock <my.bin> that is generated based on the http://code.google.com/p/qemu-omap3 emulator

I use the steps from http://code.google.com/p/qemu-omap3/wiki/UserManual, with the difference that I do not need to load Linux + RootFS, just kernel: so I use

./qemu-system-arm -M beagle -mtdblock beagle-nand.bin


and once in the emulated Uboot console type:




<br>nand read 0x80000000 0x280000 0x400000<br>go 0x80000000<br><br>

I use something similar on the real hardware (mmcinit,fatload, go) and it works.

But is crashing the original qemu -omap3 emulator.

I thought on using the emulator from maemo: garage: Exiting with error and see if the emulation crashes in the same way.



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So I built the qemu emulator from maemo (succesfully in ubuntu 9.04 desktop) and am attempting to to the same steps:
- load my bin into the maemo qemu-system-arm via:

qemu-system-arm -M beagle -mtdblock<my.bin>




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I try to connect Using Remote Desktop viewer in ubuntu 9.04 desktop edition to 127.0.0.1:5900.
I see nothing in the VNC viewer.
Ctrl-Alt-1, Ctrl-Alt-2, Ctrl-Alt-3 do nothing.
I see nothin (no Xloader/UBoot output) in the terminal:

gabi@gabi-linux:/proj/git/vmxdroid/okl4$ qemu-system-arm-beagle-maemo -M beagle -mtdblock build_bgktest/images/beagle-nand.bin
VNC server running on `127.0.0.1:5900’
omap_venc_write: Bad register 0x0000000c (value 0x00000000)
omap_venc_write: Bad register 0x00000018 (value 0x00000000)
omap_venc_write: Bad register 0x0000008c (value 0x00000000)
omap_venc_write: Bad register 0x00000098 (value 0x00000000)
omap_venc_write: Bad register 0x0000009c (value 0x00000000)
omap_venc_write: Bad register 0x000000ac (value 0x00000000)
omap_venc_write: Bad register 0x000000bc (value 0x00000000)
omap_venc_write: Bad register 0x000000c0 (value 0x00000000)




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So I try the following: nographic mode in qemu.
I see output but I can’t write into the terminal window any more (I can’t close the simulation via Ctrl-C, or interact with the emulated Uboot console):

qemu-system-arm-beagle-maemo -M beagle -mtdblock build_bgktest/images/beagle-nand.bin -nographic


Texas Instruments X-Loader 1.41
Starting OS Bootloader…


U-Boot 1.3.3 (Nov 23 2008 - 18:48:04)

OMAP3530-GP rev 2, CPU-OPP2 L3-165MHz
OMAP3 Beagle Board + LPDDR/NAND
DRAM: 128 MB
NAND: 256 MiB
*** Warning - bad CRC or NAND, using default environment

In: serial
Out: serial
Err: serial
omap_venc_write: Bad register 0x0000000c (value 0x00000000)
omap_venc_write: Bad register 0x00000018 (value 0x00000000)
omap_venc_write: Bad register 0x0000008c (value 0x00000000)
omap_venc_write: Bad register 0x00000098 (value 0x00000000)
omap_venc_write: Bad register 0x0000009c (value 0x00000000)
omap_venc_write: Bad register 0x000000ac (value 0x00000000)
omap_venc_write: Bad register 0x000000bc (value 0x00000000)
omap_venc_write: Bad register 0x000000c0 (value 0x00000000)

Hit any key to stop autoboot: 0




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I also tried the -serial stdio option for qemu-system-arm to force the implicit serial console on my virtual beagleboard into gnome terminal. No luck.

I need some help in identifying the correct command to give to be able to interact with my qemu-system-arm emulation, in order to check microkernel simulation behavior.

I hope somebody can help me.


Thank you for your help,
Gabi Voiculescu


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2

So nobody uses the maemo beagleboard port of qemu?

Thanks,
Gabi Voiculescu

3

New problem.

I began making my microkernel code compatible with the original qemu-omap3: http://code.google.com/p/qemu-omap3.

Code still works fine on the real hardware.

I had issues due to unknown or bandwidth restricted accesses in INTC, MPU_INTCPS, PRCM_WKUP_CM, PRCM_PER_CM.

Now I crash qemu in the init stage of the microkernel with the mesage:

qemu: fatal: bad error 0

I got a hit on google, and the answer was related to qemu-'s restrictions imposed on memory. I currently assume (did not have enough time to test this) that I crash in the init stage when I allocate the physical ram to the kernel and I crash beacause I do not respect the qemu memory model …

Can anybody tell me the qemu-omap3 restrictions for:

  • dram size
  • nand size

Or where I should look for them in the qemu-omap3 sources.

I currently have my build system setup for 256MB DRAM (like I saw in the Beagleboard Rev C3 spec).

Thanks,
Gabi Voiculescu

4

So nobody uses emulators to debug beagleboard code?
Hmmm.

Gabi Voiculescu

5

Sorry, printf’s and now (just recently) openocd…

Regards,

6

You clearly demonstrated how working with simulators can
be useless if the simulators can't be trusted, which is the
case here :slight_smile:

Laurent