Thanks Ali, that was it!
As I suspected, my .config file attempts where way off from what they
should have been. The .config file you sent me appears to be working
great so far.
Also, thanks for letting me know that the debugger function is
'debugger()' not 'Debugger()'. Unfortunately, I'm still encountering
problems when calling the kernel debugger from the user-level debugger
on M5. So the calls to 'debugger()' don't encounter a symbol not
found
error, but they don't break into the kernel debugger either. Instead,
nothing seems to happen. Actually after examining the function
debugger() in src/base/remote_gdb.cc, I'm not sure how the gdb is ever
called. It appears the current_debugger static int is set to -1 and
there is no possibility to set the current_debugger variable to a
different value. Thus the debugger loop is not executed and the
kernel
gdb session is never called. Is my understanding correct, or does
some
external object change the value of current_debugger? Below is the
specific code I'm referring to.
Thanks again for all your help. I really appreciate it.
Brad
void
debugger()
{
static int current_debugger = -1;
if (current_debugger >= 0 && current_debugger < debuggers.size()) {
BaseRemoteGDB *gdb = debuggers[current_debugger];
if (!gdb->isattached()) {
gdb->listener->accept();
}
if (gdb->isattached()) {
gdb->trap(SIGILL);
}
}
}
-----Original Message-----
From: Ali Saidi [mailto:[EMAIL PROTECTED]
Sent: Monday, June 02, 2008 6:29 PM
To: Beckmann, Brad
Subject: Re: [m5-users] Config File for Linux 2.6.22
On Jun 2, 2008, at 8:16 PM, Beckmann, Brad wrote:
Hi Ali,
I've been having problems creating a build of Linux 2.6.22 that
matches with the supported Tsunami platform in M5. I think the
source
of problems is incorrectly configuring the VGA device and I want to
go
back to the configuration question (see below) that I asked a few
weeks ago.
I noticed that the M5 patches make changes to the following files:
arch/alpha/Kconfig, arch/alpha/kernel/console.c, and
arch/alpha/kernel/proto.h. In particular, these changes appear to
allow the DUMMY_CONSOLE to be built without the VGA_HOSE being
defined. To avoid the define dependencies on VGA_HOSE, the changes
also switch some "#ifdef CONFIG_VGA_HOSE" lines to "#ifdef
CONFIG_VGA_HOSE1". Is my understanding correct?
Yea, some dependence was introduced in the 2.6.22 kernel that I really
haven't looked at, but that required a VGA adapter to be added to
configuration. Since we don't even support probing of the VGA device,
that had to be removed.
The problem with these changes is they appear incomplete without the
necessary changes to the config files. Specifically, I assume one
needs to remove the dependency between VGA_HOSE and ALPHA_GENERIC in
Kconfig.
Therefore, CONFIG_DUMMY_CONSOLE, CONFIG_ALPHA_GENERIC, and
CONFIG_ALPHA_LEGACY_START_ADDRESS are defined, while
CONFIG_VGA_CONSOLE, CONFIG_VGA_HOSE, and CONFIG_VGA_HOSE1 are not
defined. The result is the kernel builds with empty implementations
of the
find_console_vga_hose() and locate_and_init_vga() functions. Is my
configuration assumption correct?
Well, all you need to do is not enable any VGA adapters in your kernel
configuration file and there isn't a problem.
So with the above configuration, I encounter a M5 assertion check
that
appears to be caused by an incorrectly "faked" device. In
particular,
the following trace indicates the faulting address is 0x801fc0001ef
which maps in between the fake_ata0 and fake_ata1 devices. I have a
sucpicion that this error is caused by the vga device not really
being
removed, but I'm not sure. What is your opinion?
1942464295500: testsys.membus: recvAtomic: packet src 3 dest -1 addr
0x801fc0001ef cmd ReadReq
1942464295500: testsys.membus: Unable to find destination for addr:
0x801fc0001ef, will use default port
1942464295500: testsys.membus.responder: Device
testsys.membus.responder
read to bad address va=0x801fc0001ef size=1
The VGA device has a BadDevice where it is, I don't know why you're
seeing that.
Finally, I wanted to get a stack trace of the kernel when this error
occurs, but I'm having a problem calling the Linux kernel debugger
from
the user-level debugger on M5. The website
(http://www.m5sim.org/wiki/index.php/Debugging_M5) indicates the
kernel
debugger can be called by a 'call Debugger()' command, but I think
that
is assuming the Debugger() function is defined? Who defines the
Debugger function, because I receive a 'No symbol "Debugger" in
current
context.' Error when I try to call the Debugger function from the M5
debugger.
The case on the webpage is wrong, it should be debugger(). The
function is defined in remote_gdb.cc although you would need to
schedule a break cycle (schedBreakCycle() from within the gdb instance
that is debugging m5 would work), before you hit that error.
I've attached a linux 2.6.22 config file I just created. It builds and
successfully boots to the bash prompt.
Ali
