Benjamin Herrenschmidt writes:
> > -Memory: 255872k available (1788k kernel code, 976k data, 144k init, 0k
> > highmem)
> > +Memory: 255872k available (1776k kernel code, 0k data, 144k init, 0k
> > highmem)
>
> That is weird... (0k data)
>
> > AGP special page: 0xcffff000
> > Calibrating delay loop... 830.66 BogoMIPS (lpj=4153344)
> > Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
> > @@ -132,13 +132,7 @@
> > VFS: Mounted root (ext3 filesystem) readonly.
> > Freeing unused kernel memory: 144k init 4k chrp 8k prep
> > usb 3-2: new full speed USB device using ohci_hcd and address 2
> > -hub 3-2:1.0: USB hub found
> > -hub 3-2:1.0: 3 ports detected
> > -usb 3-2.1: new low speed USB device using ohci_hcd and address 3
> > -input: USB HID v1.10 Mouse [Logitech Apple Optical USB Mouse] on
> > usb-0001:10:1b.0-2.1
> > -usb 3-2.3: new full speed USB device using ohci_hcd and address 4
> > -input: USB HID v1.10 Keyboard [Mitsumi Electric Apple Extended USB
> > Keyboard] on usb-0001:10:1b.0-2.3
> > -input: USB HID v1.10 Device [Mitsumi Electric Apple Extended USB
> > Keyboard] on usb-0001:10:1b.0-2.3
> > +usb 3-2: can't connect bus-powered hub to this port
> > EXT3 FS on hda5, internal journal
> > Adding 1048568k swap on /dev/hda3. Priority:-1 extents:1
> > SCSI subsystem initialized
> >
> > Note: "Memory: ... 0k data ..." !? Surely that can't be correct.
>
> Not sure what's up, but it's probably something beeing miscompiled. Can
> you check if the udelay/medlay loops are correct ?
Both __delay and a few test functions using udelay/mdelay look Ok.
_However_, the 0k data message is due to a gcc-4.0 bug, and below
you'll find a test program which illustrates it.
/Mikael
/* gcc4bug.c
* Written by Mikael Pettersson <[EMAIL PROTECTED]>, 2005-02-24.
*
* This program is abstracted from arch/ppc/mm/init.c in
* the 2.6.11-rc4 Linux kernel sources.
*
* With gcc-3.4.3, gcc-3.3.5, or gcc-3.2.3, mem_init()
* correctly returns 245.
*
* With gcc-4.0.0 20050220, mem_init() erroneously returns 0.
* The error occurs with -O1, and -O2.
* Compiling at -O0, or -O3 or higher, hides the error.
*
* All gcc versions were configured for powerpc-unknown-linux-gnu.
*/
#include <stdio.h>
#define PAGE_SIZE 4096
unsigned long PAGE_OFFSET;
unsigned long high_memory;
unsigned long etext;
unsigned long init_begin;
unsigned long init_end;
unsigned long klimit;
int mem_init(void)
{
unsigned long addr;
int codepages = 0;
int datapages = 0;
int initpages = 0;
for (addr = PAGE_OFFSET; addr < high_memory; addr += PAGE_SIZE) {
if (addr < etext)
codepages++;
else if (addr >= init_begin && addr < init_end)
initpages++;
else if (addr < klimit)
datapages++;
}
printf("datapages == %d, initpages == %d, codepages == %d\n",
datapages, initpages, codepages);
return datapages;
}
int main(void)
{
int datapages;
PAGE_OFFSET = 0xc0000000;
etext = 0xc01bb958;
init_begin = 0xc0264000;
init_end = 0xc0288000;
klimit = 0xc02d4378;
high_memory = 0xd0000000;
datapages = mem_init();
if (datapages != 245) {
fprintf(stderr, "gcc bug! mem_init() returned %d\n", datapages);
return 1;
} else
return 0;
}
-
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