Re: new board

Stefano Martini
2004-04-28T13:30:42Z

Thanks for the help,

I have defined all the memory regions for my board in
the file interp.c:

sim_do_command(sd,"memory region ......")

When I start the run program (mipsel-elf-run --board .....) to execute
a example program I get the following error messages:

mips-core: 1 byte read to unmapped address 0x0 at 0x800ab230
mips-core: 4 byte read to unmapped address 0x0 at 0x0
mips-core: 4 byte read to unmapped address 0x0 at 0x0
mips-core: 4 byte read to unmapped address 0x0 at 0x0
mips-core: 4 byte read to unmapped address 0x0 at 0x0
mips-core: 4 byte read to unmapped address 0x0 at 0x0

I have no address in region 0x0. Is this a problem
related to virtual and physical addresses?

I think "physical address" is an address generated by the
processor to access a memory region.
What is a virtual address?

Thanks in advance.
Stefano

----- Original Message -----
From: cgd@broadcom.com
To: Stefano Martini
Cc: GDB
Sent: Monday, April 26, 2004 7:56 PM
Subject: Re: new board

Unfortunately, as you've discovered, there's not much documentation
related to the simulator(s)...

At Mon, 26 Apr 2004 09:57:12 +0200, Stefano Martini wrote:
> I have seen two interesting commands:
>
> sim_do_command(sd,"memory region .....")
>
> sim_do_commandf(sd,"memory alias....");
>
> Which are the differences between sim_do_command and
> sim_do_commandf ?

looking at the changelogs:

* sim-utils.c (sim_do_commandf): New function, printf version of
sim_do_command.

That difference seems borne out by their usage.

> And more, which are the differences between memory region
> and memory alias?

memory region creates a region of memory to be used by the simulator.

memory alias creates a region in the address space that aliases an
existing region of memory.

As you can see from some of the code already there, this is used to
mock-up kseg1. (This method is, IMO, not ideal.)

chris