external sdram and gdb tool

[Tom]

Hi,

I have some project where I store my entire program in the external
sdram (by redirecting every section in the linker script to the
sdram). When I download the program to the board, it doesn't work.
When I run the program in the debugger tool, it works. Does anybody
know an answer to this problem ?

regards,

Tom

 

[Ryan Laity]

Hi Tom,

How are you populating the SDRAM with your .elf file when not using the
debugger? Perhaps you're doing this properly, but you didn't mention it
here so I have to ask. When downloading the .bit file via iMPACT, the
only .elf data that you can possibly have is that in the Block RAM. If
you're not moving the .elf into SDRAM then that's the problem; you will
need a bootloader of some sort to move the data from a static location
(Flash, etc.) into SDRAM.

If you are already loading the .elf into SDRAM, then use the XMD tool to
check the validity of the .elf file in memory. What I typically do is
run an object dump (either mb-objdump or powerpc-eabi-objdump) on the
..elf file (I typically use the -S option) and pipe that out to a text
file. Next, connect to the device via XMD (ppcconnect or mbconnect) and
do mwr's from the base address of your SDRAM. If you do something like
mwr 0xF0000000 20, it will dump the 20 addresses after 0xF0000000
(obviously change this to match your SDRAM base address) and you can
check them against the .elf file. The boot section of the .elf is at
the bottom of the file so look there to start. This will check that
your bootloader is doing its job properly and that your system is able
to read from the static location (Flash, etc.) properly (we already know
that it can write to SDRAM properly because it works with the debugger).

I hope this information helps. If not, please post a follow up or open
a case with Support.


Ryan Laity
Xilinx Applications


Tom wrote:

Hi,

I have some project where I store my entire program in the external
sdram (by redirecting every section in the linker script to the
sdram). When I download the program to the board, it doesn't work.
When I run the program in the debugger tool, it works. Does anybody
know an answer to this problem ?

regards,

Tom

 

[Tom]

Hi Ryan,

I tried to connect with ppcconnect to the board, and then i downloaded
the program. Then I started the processor and the program worked.

ppcconnect
dow ppc405_0/code/executable.elf
con

Correct me if I am wrong, but is this what the bootloader should do ?
Could you be more specific about the bootloader?

Thanks,

Tom


On Wed, 26 Nov 2003 10:01:29 -0700, Ryan Laity
<ryan_dot_laity@x-i-l-i-n-x_pleasenospam_dot_com> wrote:

Hi Tom,

How are you populating the SDRAM with your .elf file when not using the
debugger? Perhaps you're doing this properly, but you didn't mention it
here so I have to ask. When downloading the .bit file via iMPACT, the
only .elf data that you can possibly have is that in the Block RAM. If
you're not moving the .elf into SDRAM then that's the problem; you will
need a bootloader of some sort to move the data from a static location
(Flash, etc.) into SDRAM.

If you are already loading the .elf into SDRAM, then use the XMD tool to
check the validity of the .elf file in memory. What I typically do is
run an object dump (either mb-objdump or powerpc-eabi-objdump) on the
.elf file (I typically use the -S option) and pipe that out to a text
file. Next, connect to the device via XMD (ppcconnect or mbconnect) and
do mwr's from the base address of your SDRAM. If you do something like
mwr 0xF0000000 20, it will dump the 20 addresses after 0xF0000000
(obviously change this to match your SDRAM base address) and you can
check them against the .elf file. The boot section of the .elf is at
the bottom of the file so look there to start. This will check that
your bootloader is doing its job properly and that your system is able
to read from the static location (Flash, etc.) properly (we already know
that it can write to SDRAM properly because it works with the debugger).

I hope this information helps. If not, please post a follow up or open
a case with Support.


Ryan Laity
Xilinx Applications


Tom wrote:

Hi,

I have some project where I store my entire program in the external
sdram (by redirecting every section in the linker script to the
sdram). When I download the program to the board, it doesn't work.
When I run the program in the debugger tool, it works. Does anybody
know an answer to this problem ?

regards,

Tom

 

[Tom]

Of course I downloaded the program first with XPS, and then I
downloaded it a second time with xmd.

I also checked the boot section:

f1000ca0 <_boot0>:
f1000ca0: 3c 00 f1 00 lis r0,-3840
f1000ca4: 60 00 00 68 ori r0,r0,104
f1000ca8: 7c 08 03 a6 mtlr r0
f1000cac: 4e 80 00 20 blr
Disassembly of section .boot:

f1000cb0 <_boot>:
f1000cb0: 4b ff ff f0 b f1000ca0 <__stack>


Tom


On Thu, 27 Nov 2003 13:40:22 +0100, Tom <t_t_1232000@yahoo.com> wrote:

Hi Ryan,

I tried to connect with ppcconnect to the board, and then i downloaded
the program. Then I started the processor and the program worked.

ppcconnect
dow ppc405_0/code/executable.elf
con

Correct me if I am wrong, but is this what the bootloader should do ?
Could you be more specific about the bootloader?

Thanks,

Tom


On Wed, 26 Nov 2003 10:01:29 -0700, Ryan Laity
ryan_dot_laity@x-i-l-i-n-x_pleasenospam_dot_com> wrote:

Hi Tom,

How are you populating the SDRAM with your .elf file when not using the
debugger? Perhaps you're doing this properly, but you didn't mention it
here so I have to ask. When downloading the .bit file via iMPACT, the
only .elf data that you can possibly have is that in the Block RAM. If
you're not moving the .elf into SDRAM then that's the problem; you will
need a bootloader of some sort to move the data from a static location
(Flash, etc.) into SDRAM.

If you are already loading the .elf into SDRAM, then use the XMD tool to
check the validity of the .elf file in memory. What I typically do is
run an object dump (either mb-objdump or powerpc-eabi-objdump) on the
.elf file (I typically use the -S option) and pipe that out to a text
file. Next, connect to the device via XMD (ppcconnect or mbconnect) and
do mwr's from the base address of your SDRAM. If you do something like
mwr 0xF0000000 20, it will dump the 20 addresses after 0xF0000000
(obviously change this to match your SDRAM base address) and you can
check them against the .elf file. The boot section of the .elf is at
the bottom of the file so look there to start. This will check that
your bootloader is doing its job properly and that your system is able
to read from the static location (Flash, etc.) properly (we already know
that it can write to SDRAM properly because it works with the debugger).

I hope this information helps. If not, please post a follow up or open
a case with Support.


Ryan Laity
Xilinx Applications


Tom wrote:

Hi,

I have some project where I store my entire program in the external
sdram (by redirecting every section in the linker script to the
sdram). When I download the program to the board, it doesn't work.
When I run the program in the debugger tool, it works. Does anybody
know an answer to this problem ?

regards,

Tom