[U-Boot-Users] questions booting Linux on a mpc8247

[U-Boot-Users] questions booting Linux on a mpc8247

[Jim Fridlund]

Hi all. I am trying to load Linux on a board with a mpc8247
processor using u-boot-1.1.4 and I'm running into a problems
booting a multi-boot image (Linux kernel + ram disk).

I can load the image via TFTP, but it hangs when I try to
run bootm. I searched in Google, but I couldn't find anything
related to what I'm seeing so I'm hoping I can get some help
from the u-boot community. What I see here is that u-boot gets
a 0x200 exception because it is trying to load the ram disk
image to memory out of range. My board has 128M of memory. Here
is a snippet:

U-Boot 1.1.4 (May 10 2006 - 11:38:41)

MPC8247 Reset Status: Check Stop, External Soft, External Hard

MPC8247 Clock Configuration
 - Bus-to-Core Mult 4x, VCO Div 2, 60x Bus Freq  25-75 , Core Freq 100-300
 - dfbrg 1, corecnf 0x1a, busdf 5, cpmdf 1, plldf 0, pllmf 5
 - vco_out  399999996, scc_clk   99999999, brg_clk   24999999
 - cpu_clk  266666664, cpm_clk  199999998, bus_clk   66666666
 - pci_clk   66666666

CPU:   MPC8247 (HiP7 Rev 14, Mask 1.0 1K50M) at 266.666 MHz
Board: MPC 8247
I2C:   ready
DRAM:  128 MB
FLASH: 512 kB
Using default environment

In:    serial
Out:   serial
Err:   serial
Net:   FCC1 ETHERNET
IDE:   Bus 0: OK
  Device 0: Model: TOSHIBA THNCF256MMA Firm: 3.10 Ser#: STCB52M6300ZC49843C5
            Type: Removable Hard Disk
            Capacity: 244.5 MB = 0.2 GB (500736 x 512)

Type "run flash_nfs" to mount root filesystem over NFS

=> tftp
Using FCC1 ETHERNET device
TFTP from server 172.16.86.50; our IP address is 172.16.86.177
Filename 'jim/uImage'.
Load address: 0x100000
Loading: #################################################################
...
done
Bytes transferred = 7326900 (6fccb4 hex)
=> bootm
## Booting image at 00100000 ...
   Image Name:   Linux with ramdisk
   Created:      2006-05-10  22:01:21 UTC
   Image Type:   PowerPC Linux Multi-File Image (uncompressed)
   Data Size:    7326836 Bytes =  7 MB
   Load Address: 00000000
   Entry Point:  00000000
   Contents:
   Image 0:  2559077 Bytes =  2.4 MB
   Image 1:  4767744 Bytes =  4.5 MB
   Verifying Checksum ... OK
OK
   Loading Ramdisk to 84344000, end 07f74064 ...

It verifies the image correctly, but the board hangs with a
0x200 exception trying to load the ram disk at 0x84344000
which is out of range. I don't know how u-boot calculates
where it stores the kernel and ram disk at the moment (this
is all magic to me). If I create an image where I specify the
load address, say 16M (0x01000000), it is able to load the ram
disk ok but hangs shortly with exception 0x200.

I generate the multi-boot image by running the following mkimage
command:

$ ./u-boot-1.1.4/tools/mkimage -A ppc -O Linux -T multi -C none -n
'Linux with ramdisk' -d vmlinux:rootfs.powerpc.ext2 uImage.img

Unfortunately, I haven't figured out how to debug u-boot after
it copies the code from rom to memory so progress has slowed.
I am using Vision Probe to debug. I can debug the code prior to
copying itself into memory, but I lose symbols once it relocates
to memory. Does anyone have any advice on how to tackle this? I
saw the GDB serial debug tutorial, but I don't have another serial
port unfortunately.

I also have a question regarding tool chain. I am using uClibC's
buildroot to build a compiler toolchain. At the moment, I am using
gcc 3.4.2 and Linux 2.4.31. I tried using gcc 4.0.2 initially, but
I had a problem with it trying to generate the proper code for
building u-boot. It appears that u-boot is using register r29 as
a global pointer and we had the following code in
./cpu/mpc8260/cpu_init.c:

void cpu_init_f (volatile immap_t * immr)
{
        DECLARE_GLOBAL_DATA_PTR;
        ...

        /* Pointer is writable since we allocated a register for it */
        gd = (gd_t *) (CFG_INIT_RAM_ADDR + CFG_GBL_DATA_OFFSET);
}

For the PPC, DECLARE_GLOBAL_DATA_PTR is defined as:

#define DECLARE_GLOBAL_DATA_PTR     register volatile gd_t *gd asm ("r29")

As far as I can tell, the above statement is trying to assign
r29 the value of CFG_INIT_RAM_ADDR + CFG_GBL_DATA_OFFSET which
is basically an offset in the PPC's internal memory for storing
global data structure. However, gcc 4.0.2 would not generate code
that sets r29 correctly. I temporarily worked around it by adding
a couple of lines in start.S:

        /* Hack to initialize R29 since cpu_init_f code isn't working. */
        lis     r29,(CFG_INIT_RAM_ADDR + CFG_GBL_DATA_OFFSET)@h
        ori     r29, r29, (CFG_INIT_RAM_ADDR + CFG_GBL_DATA_OFFSET)@l

Is anyone using gcc 4.x to build? I reverted to gcc 3.4.2 just to
be on the safe side. Also, I noticed that Linux 2.6.x kernel doesn't
have much support for embedded mpc82xx so I ended up using Linux 2.4.31
which is the most current version that works with uClibC's buildroot.
Is there anyone doing embedded PPC development based on 2.6 kernel and
gcc 4.x? I sure would like to hear your inputs.

Lastly, is there anyone working on a TIPC implementation in u-boot?
I read the white paper on TIPC and it would seem like a nice solution
to have on a distributed/embedded cluster environment such as a
chassis where there is a single control card with multiple dummy
line cards (flashless) on a custom backplane.

Any help or pointers would be greatly appreciated. Thanks in advance.
--
Jim

[U-Boot-Users] questions booting Linux on a mpc8247

[Sam Song]

Jim Fridlund <jim@code4fun.us> wrote:
[snip] 
> I can load the image via TFTP, but it hangs when I
> try to run bootm. I searched in Google, but I 

If you can boot kernel via NFS, the problem must be
your bootargs settings in u-boot. Try to type
the cmdline to here for check.

Regards,

Sam




		
___________________________________________________________ 
????????-3.5G???20M??? 
http://cn.mail.yahoo.com

[U-Boot-Users] questions booting Linux on a mpc8247

[Jim Fridlund]

Hi Sam,

Ultimately, I would like to load a multi-boot image
kernel + ram disk in a single file off the compact
flash (IDE) drive. At the moment, I just got the IDE
driver working. I had some problems with endian issue
as my IDE interface is basically implemented as a CPLD.
Even though I'm a big endian system, the IDE registers
are little endian so I had to add special CFG arguments
to get the IDE to recognize the drive. I'm also having
problems trying to access the DOS file system. This is
something I can pursue once I get linux bootstrapped
though.

When I started with u-boot, I looked at the various
boards in the list. I used IDS8247 as a reference since
it was the same PPC8247. I realize I probably don't
have the boot parameters set up correctly (I don't
have NVRAM environment), but I figure I should still
be allowed to boot.

Here is my hardcoded info in the board specific header:

#define CONFIG_EXTRA_ENV_SETTINGS                                       \
        "netdev=eth0\0"                                                 \
        "nfsargs=setenv bootargs root=/dev/nfs rw "                     \
                "nfsroot=${serverip}:${rootpath}\0"                     \
        "ramargs=setenv bootargs root=/dev/ram rw "                     \
        "console=ttyS0,57600\0"                                         \
        "addip=setenv bootargs ${bootargs} "                            \

"ip=172.16.86.177:172.16.86.50:172.16.86.254:255.255.255.0"
\
                ":jim-r100:eth0:off panic=1\0"                  \
        "flash_nfs=run nfsargs addip;"                                  \
                "bootm ${kernel_addr}\0"                                \
        "flash_self=run ramargs addip;"                                 \
                "bootm ${kernel_addr} ${ramdisk_addr}\0"                \
        "net_nfs=tftp 200000 ${bootfile};run nfsargs addip;bootm\0"     \
        "rootpath=/opt/eldk/ppc_82xx\0"                                 \
        "bootfile=jim/uImage\0"                                         \
        "kernel_addr=ff800000\0"                                        \
        "ramdisk_addr=ffa00000\0"                                       \
        "ethaddr=00:01:47:01:02:03\0"                                   \
        "ipaddr=172.16.86.177\0"                                        \
        "serverip=172.16.86.50\0"                                       \
        "verify=y\0"                                                    \
        ""
#define CONFIG_BOOTCOMMAND      "run flash_self"

Thanks.
--
Jim

Sam Song wrote:
> Jim Fridlund <jim@code4fun.us> wrote:
> [snip] 
>> I can load the image via TFTP, but it hangs when I
>> try to run bootm. I searched in Google, but I 
> 
> If you can boot kernel via NFS, the problem must be
> your bootargs settings in u-boot. Try to type
> the cmdline to here for check.
> 
> Regards,
> 
> Sam

[U-Boot-Users] questions booting Linux on a mpc8247

[Sam Song]

Jim Fridlund <jim@code4fun.us> wrote:
>         "ramargs=setenv bootargs root=/dev/ram rw " 
>                    \
>         "console=ttyS0,57600\0"                     

Well, pls try 

=> tftp 200000
=> setenv kernel_addr 200000
=> tftp 1200000 <ramdisk>
=> setenv ramdisk_addr 1200000
=> run flash_self

You cannot boot kernel at 0x100000.

Best regards,

Sam


		
___________________________________________________________ 
??????-3.5G???20M?? 
http://cn.mail.yahoo.com/

[U-Boot-Users] questions booting Linux on a mpc8247

[Jim Fridlund]

Hi Sam,

I'm a little closer. ;-) The Vision Probe failed
trying to run code at PC=0x00000000.

=> printenv
bootcmd=run flash_self
baudrate=57600
loads_echo=1
preboot=echo;echo Type "run flash_nfs" to mount root filesystem over
NFS;echo
netdev=eth0
nfsargs=setenv bootargs root=/dev/nfs rw nfsroot=${serverip}:${rootpath}
ramargs=setenv bootargs root=/dev/ram rw console=ttyS0,57600
addip=setenv bootargs ${bootargs}
ip=172.16.86.177:172.16.86.50:172.16.86.254:255.255.255.0:jim-r100:eth0:off
panic=1
flash_nfs=run nfsargs addip;bootm ${kernel_addr}
flash_self=run ramargs;bootm ${kernel_addr} ${ramdisk_addr}
net_nfs=tftp 200000 ${bootfile};run nfsargs addip;bootm
rootpath=/opt/eldk/ppc_82xx
bootfile=jim/uImage
kernel_addr=20000
ramdisk_addr=1200000
ethaddr=00:01:47:01:02:03
ipaddr=172.16.86.177
serverip=172.16.86.50
verify=y
stdin=serial
stdout=serial
stderr=serial
ethact=FCC1 ETHERNET
bootcount=49

Environment size: 798/65532 bytes
=> tftp 20000 jim/uImage.img
Using FCC1 ETHERNET device
TFTP from server 172.16.86.50; our IP address is 172.16.86.177
Filename 'jim/uImage.img'.
Load address: 0x20000
Loading: #################################################################
...
done
Bytes transferred = 2559141 (270ca5 hex)
=> tftp 1200000 jim/ram.img
Using FCC1 ETHERNET device
TFTP from server 172.16.86.50; our IP address is 172.16.86.177
Filename 'jim/ram.img'.
Load address: 0x1200000
Loading: #################################################################
...
done
Bytes transferred = 4767808 (48c040 hex)
=> run flash_self
## Booting image at 00020000 ...
   Image Name:   Linux
   Created:      2006-05-11   5:12:04 UTC
   Image Type:   PowerPC Linux Kernel Image (uncompressed)
   Data Size:    2559077 Bytes =  2.4 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
OK
## Loading RAMDisk Image at 01200000 ...
   Image Name:   Ramdisk
   Created:      2006-05-11   5:13:09 UTC
   Image Type:   PowerPC Linux RAMDisk Image (uncompressed)
   Data Size:    4767744 Bytes =  4.5 MB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
   Loading Ramdisk to 07ae7000, end 07f73000 ... OK

This is the disassembled output at address 0 from the
Vision probe.

 $00000000   dc.l           0x7f454c46
 $00000004   dc.l           0x1020100
 $00000008   dc.l           0x0
 $0000000C   dc.l           0x0
 $00000010   dc.l           0x20014
 $00000014   dc.l           0x1
 $00000018   lfs            F0,0x0(R0)
 $0000001C   dc.l           0x34
 $00000020   dc.l           0x1e8634
 $00000024   dc.l           0x0
 $00000028   dc.l           0x340020
 $0000002C   dc.l           0x20028
 $00000030   dc.l           0x1b0018

It doesn't look like valid code and it sure
does not match the code that I'm expecting from
the vmlinux ELF image.

$ ${CROSS_COMPILE}objdump -d vmlinux  | head -20

vmlinux:     file format elf32-powerpc

Disassembly of section .text:

c0000000 <_start>:
c0000000:       60 00 00 00     nop
c0000004:       60 00 00 00     nop
c0000008:       60 00 00 00     nop

c000000c <__start>:
c000000c:       7c 7f 1b 78     mr      r31,r3
c0000010:       7c 9e 23 78     mr      r30,r4
c0000014:       7c bd 2b 78     mr      r29,r5
c0000018:       7c dc 33 78     mr      r28,r6
c000001c:       7c fb 3b 78     mr      r27,r7
c0000020:       3b 00 00 00     li      r24,0
c0000024:       48 1c 5c 21     bl      c01c5c44 <early_init>
c0000028:       48 00 37 11     bl      c0003738 <mmu_off>

For sure, the code at address 0 doesn't match
code at c0000000. So, I'm still probably not
doing something correctly in u-boot.

$ ${CROSS_COMPILE}nm --numeric-sort vmlinux | head -20
         w __start___kallsyms
         w __stop___kallsyms
00000005 a LG_CACHELINE_BYTES
0000000c a Hash_bits
0000001f a CACHELINE_MASK
00000020 a CACHELINE_BYTES
0003ffc0 a Hash_msk
c0000000 T _start
c0000000 T _stext
c000000c T __start
c000002c t __after_mmu_off
c0000064 t turn_on_mmu
c00000c4 T __secondary_hold
c0000100 t Reset
c0000190 t i0x100
c0000200 t MachineCheck
c0000290 t i0x200
c0000300 t DataAccess
c00003bc t i0x300
c0000400 t InstructionAccess

I'm a couple steps closer though. So, is multi-image boot
not supported?

Thanks again for your help.
--
Jim

Sam Song wrote:
> Jim Fridlund <jim@code4fun.us> wrote:
>>         "ramargs=setenv bootargs root=/dev/ram rw " 
>>                    \
>>         "console=ttyS0,57600\0"                     
> 
> Well, pls try 
> 
> => tftp 200000
> => setenv kernel_addr 200000
> => tftp 1200000 <ramdisk>
> => setenv ramdisk_addr 1200000
> => run flash_self
> 
> You cannot boot kernel at 0x100000.
> 
> Best regards,
> 
> Sam
> 
> 
> 		
> ___________________________________________________________ 
> ??????-3.5G???20M?? 
> http://cn.mail.yahoo.com/

[U-Boot-Users] questions booting Linux on a mpc8247

[Jim Fridlund]

Jim Fridlund wrote:
>  $00000000   dc.l           0x7f454c46
>  $00000004   dc.l           0x1020100
>  $00000008   dc.l           0x0
>  $0000000C   dc.l           0x0
>  $00000010   dc.l           0x20014
>  $00000014   dc.l           0x1
>  $00000018   lfs            F0,0x0(R0)
>  $0000001C   dc.l           0x34
>  $00000020   dc.l           0x1e8634
>  $00000024   dc.l           0x0
>  $00000028   dc.l           0x340020
>  $0000002C   dc.l           0x20028
>  $00000030   dc.l           0x1b0018

I just realized that the byte patterns above matches
exactly what my vmlinux ELF image. Here is the hex
dump:

00000000  7f 45 4c 46  01 02 01 00  00 00 00 00  00 00 00 00
.ELF............
00000010  00 02 00 14  00 00 00 01  c0 00 00 00  00 00 00 34
...............4
00000020  00 1e 86 34  00 00 00 00  00 34 00 20  00 02 00 28
...4.....4. ...(
00000030  00 1b 00 18  00 00 00 01  00 01 00 00  c0 00 00 00
................
00000040  c0 00 00 00  00 1d 60 b4  00 20 8c 3c  00 00 00 07  ......`..
.<....
00000050  00 01 00 00  64 74 e5 51  00 00 00 00  00 00 00 00
....dt.Q........
00000060  00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 07
................

So, u-boot appears to have extracted the image correctly
and relocated it to address 0, but I'm thinking I probably
need to install a pure binary instead of an ELF image?
Does u-boot understand ELF or does it only expect a pure
binary?

Thanks again!
--
Jim

[U-Boot-Users] questions booting Linux on a mpc8247

[Wolfgang Denk]

In message <4462ACC9.8060206@code4fun.us> you wrote:
> 
> I can load the image via TFTP, but it hangs when I try to
> run bootm. I searched in Google, but I couldn't find anything

Maybe reading the FAQ helps?

See http://www.denx.de/wiki/view/DULG/LinuxUncompressingError

> related to what I'm seeing so I'm hoping I can get some help
> from the u-boot community. What I see here is that u-boot gets
> a 0x200 exception because it is trying to load the ram disk
> image to memory out of range. My board has 128M of memory. Here
> is a snippet:

Yes, this is a consequence of the image overwriting itself.

> I also have a question regarding tool chain. I am using uClibC's
> buildroot to build a compiler toolchain. At the moment, I am using
> gcc 3.4.2 and Linux 2.4.31. I tried using gcc 4.0.2 initially, but
> I had a problem with it trying to generate the proper code for
> building u-boot. It appears that u-boot is using register r29 as
> a global pointer and we had the following code in
> ./cpu/mpc8260/cpu_init.c:

Please use current U-Boot code, where such issues have been fixed.

> Is anyone using gcc 4.x to build? I reverted to gcc 3.4.2 just to

Yes, we do. ELDK 4.0 uses gcc-4.0, and this works fine.

> Is there anyone doing embedded PPC development based on 2.6 kernel and
> gcc 4.x? I sure would like to hear your inputs.

ELDK-4.0 is based on a 2.6 kernel, and includes support for a  couple
of MPC82xx boards.

> Lastly, is there anyone working on a TIPC implementation in u-boot?

No. U-Boot isa boot loader, not an OS.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Software entities are more complex for their size  than  perhaps  any
other human construct because no two parts are alike. If they are, we
make  the  two  similar parts into a subroutine -- open or closed. In
this respect, software  systems  differ  profoundly  from  computers,
buildings, or automobiles, where repeated elements abound.
                                                   - Fred Brooks, Jr.

[U-Boot-Users] questions booting Linux on a mpc8247

[Wolfgang Denk]

In message <20060511045400.58716.qmail@web15902.mail.cnb.yahoo.com> you wrote:
> 
> You cannot boot kernel at 0x100000.

You can, if it's small enough.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"A verbal contract isn't worth the paper it's printed on."
- Samuel Goldwyn

[U-Boot-Users] questions booting Linux on a mpc8247

[Wolfgang Denk]

In message <4462CFFE.3010404@code4fun.us> you wrote:
> 
> I'm a little closer. ;-) The Vision Probe failed
> trying to run code at PC=0x00000000.

Maybe you try again after disconnecting your Vision Probe.

> I'm a couple steps closer though. So, is multi-image boot
> not supported?

Of course it is. It's working fine here.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Physician: One upon whom we set our hopes when ill and our dogs  when
well.                                                - Ambrose Bierce

[U-Boot-Users] questions booting Linux on a mpc8247

[Wolfgang Denk]

In message <4462D187.5090501@code4fun.us> you wrote:
>
> I just realized that the byte patterns above matches
> exactly what my vmlinux ELF image. Here is the hex
> dump:

Which means you did you build the image correctly. RTFM.

> So, u-boot appears to have extracted the image correctly

Yes, U-Boot works fine, but it cannot fix operator errors.

> Does u-boot understand ELF or does it only expect a pure
> binary?

RTFM!

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
If it happens once, it's a bug.
If it happens twice, it's a feature.
If it happens more than twice, it's a design philosophy.

[U-Boot-Users] questions booting Linux on a mpc8247

[Sam Song]

--- Wolfgang Denk <wd@denx.de> wrote:
> Jim Fridlund <jim@code4fun.us> wrote:
> > Does u-boot understand ELF or does it only expect
> > a pure binary?
> 
> RTFM!

Pls try the binary image instead. U-Boot can boot
binary image by default.It locates at 
arch/ppc/boot/images/ in kernel code. I just noticed
that you used ELF kernel. Wrong way...

Regards,

Sam


		
___________________________________________________________ 
????????-3.5G???20M??? 
http://cn.mail.yahoo.com

[U-Boot-Users] questions booting Linux on a mpc8247

[Sam Song]

--- Wolfgang Denk <wd@denx.de> wrote:
> > You cannot boot kernel at 0x100000.
> 
> You can, if it's small enough.
> 

Thanks for this correction. Well, for kernel
boot address, 0x200000 is a better choice than
0x100000 usually.

Sam


		
___________________________________________________________ 
????????-3.5G???20M??? 
http://cn.mail.yahoo.com