[okl4-developer] Help with SoC Porting

Kumar Sanghvi divinekumar at gmail.com
Thu Sep 17 09:06:20 EST 2009 

Hi All,

I need some help with SoC porting part.
I have written some code for OKL4 3.0 port for Beagleboard. The code is
compiling fine and generating images.
I try to load the image in Qemu-omap3 simulator and it exits with below
error message:-
"Unassigned mem writew 48070008 = 0xffff pc 80e9b298"

I try to load the image on Beagleboard and nothing comes on serial terminal.

It is very possible that my serial code is not written correctly. But, since
the simulator is exiting with some memory related messages, I am doubtful if
I have set the parameters for
-memory[physical], memory[virtual] and vbase_address correctly.



Following is the build command-line. The below error message comes if I
don't specify or wrongly specify values for memory[virtual] and
vbase_address in arch/arm/tools/machines.py for the cortexa8 definition:-
========================================================================================================================================================
[root at localhost okl4_3.0-armv6]# ./tools/build.py MACHINE=beagle
PROJECT=examples EXAMPLE=hello TOOLCHAIN=gnu_arm_eabi_toolchain
pistachio.TOOLCHAIN=gnu_arm_toolchain PYFREEZE=false kdb_serial=true
kdb_breakin=false debug_trace=5 verbose_init=true
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
[ELF ] build/images/image.elf
Error:
Now printing a traceback.

Traceback (most recent call last):
  File "tools/pyelf/elfweaver.py", line 79, in ?
    main(sys.argv)
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/main.py",
line 108, in main
    __commands__[args[1]](args[2:])
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/merge.py",
line 270, in merge_cmd
    merge(spec_file, options)
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/merge.py",
line 166, in merge
    namespace, image)
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/merge.py",
line 103, in collect_image_objects
    pool.collect_xml(el, machine, pools)
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/pools.py",
line 128, in collect_xml
    pools.add_physical_memory(self.name, machine, src=src, base=base,
size=size)
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/pools.py",
line 574, in add_physical_memory
    self.physical_pools[physpool].add_memory(base, size, mem_type)
  File
"/home/kumar/Hypervisor/OKL/experimental-okl4-30-beagleboard-porting/okl4_3.0-armv6/tools/pyelf/weaver/allocator.py",
line 352, in add_memory
    assert size % self.min_alloc == 0
AssertionError

scons: *** [build/images/image.elf] Error 1
scons: building terminated because of errors.
========================================================================================================================================================

I then set the following values and build compiles fine generating image

=>platform/omap3530/tools/machines.py:
   memory[physical] = [Region(0x80000000, 0x82000000)]

=>arch/arm/tools/machines.py
   class armv7(arm):
    memory = arm.memory.copy()
    #memory['virtual'] = [Region(0x1000, 0xe0000000)] # Trap NULL pointer
derefs.
    base_vaddr = 0x10000000
    memory['virtual'] = [Region(0x1000, 0xd0000000)] # Trap NULL pointer
derefs.
    #memory['virtual'] = [Region(0x80000000, 0xd0000000)] # Trap NULL
pointer derefs.
    #memory['virtual'] = [Region(0x1000, 0xe0000000)] # Trap NULL pointer
derefs.

   class armv7a(armv7):
    cpp_defines = armv7.cpp_defines + [("__ARMv__", 7), "__ARMv7A__"]
    arch_version = 7

   class cortexa8(armv7a):
        c_flags = armv7a.c_flags
        cpu = "cortexa8"


======================================================================================================================================================================
I have attached readelf output for the generated elf image with this mail.


=======================================================================================================================================================================

Below is sequence of output from qemu-omap3 simulator

omap3-sim output:-

omap_venc_write: Bad register 0x48050c00
omap_venc_write: Bad register 0x48050c04
omap_venc_write: Bad register 0x48050c8c
omap_venc_write: Bad register 0x48050c98
omap_venc_write: Bad register 0x48050c9c
omap_venc_write: Bad register 0x48050cac
omap_venc_write: Bad register 0x48050cbc
omap_venc_write: Bad register 0x48050cc0
omap_diss_write: Bad register 0x48050044
omap_diss_write: Bad register 0x48050048
omap_diss_write: Read-only register 0x48050050
omap_diss_write: Read-only register 0x48050058
omap_disc_write: Bad register 0x48050414
omap_disc_write: Bad register 0x480504a8

At this point, u-boot prompt is available and I give below command at u-boot
prompt:-
beagleboard#mmcinit;fatload mmc 0 80000000 image.elf;go 80000000

The simulator simply exits with below line:-
Unassigned mem writew 48070008 = 0xffff pc 80e9b298
   //This error message might indicate something
[root at localhost arm-softmmu]#

==============================================================================================================================================================


So, at this point, below are some possible failure points:-
1. Parameters for memory[physical],memory[virtual] and base_vaddress are
wrongly given, so memory layout is not proper in the generated elf file.
2. u-boot arguments given are wrong.
3. Serial code written in platform/omap3530/pistachio/kdb/console.c is
wrong, as nothing is coming on screen.
4. If serial code is fine, and considering that build is made with
'verbose_init=true', atleast some output should come from
arch/arm/pistachio/src/init.cc file.
   But as nothing is coming on screen, not sure what is happenning.

Really not able to make out where to start debugging / troubleshooting at
this point.
Please help with any suggestions / advise.

Thanks,
Kumar.
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