see /usr/src/linux/Documentation/kbuild/command.txt:
the difference between 'zImage' files and 'bzImage' files is that
'bzImage' uses a different layout and a different loading algorithm,
and thus has a larger capacity. Both files use gzip compression.
The 'bz' in 'bzImage' stands for 'big zImage', not for 'bzip'!
Ruby
----- Original Message -----
From: "Norbert Roos" <n.roos@berlin.de>
To: <kernelnewbies@nl.linux.org>
Sent: Wednesday, September 26, 2001 12:34 AM
Subject: How to make a DMA over PCI?
> Hello!
>
> I have a PCI device and I want this to transfer data to and from main
> memory by using DMA as PCI master. Shouldn't be a huge problem, I
> thought.
>
> The problems start with the bus address of the main memory. The
> following module prints the bus address of a variable:
>
>
> static unsigned int var;
>
> int init_module(void) {
>
> printk(KERN_ERR "&var = 0x%08x\n", &var);
> printk(KERN_ERR "virt_to_bus(&var) = 0x%08x\n", virt_to_bus(&var));
>
> return -1;
> }
>
>
> Result is
>
> virt_to_bus(&var) = 0x0d915340
>
>
> This address (a bit below 256M) seems to me too high, because the
> machine is equipped with only 128 MB and I expect the main memory to
> start at address 0. When the PCI device accesses this address, there is
> no response (the host bridge answers correctly as selected device, but
> then continuously puts a "Target not ready" on the PCI bus, with no
> abort). Can this address anyway be a valid bus address?
>
> Next problem: The most effective DMA transfer copies data directly from
> the PCI device to user space memory. How do I find out the physical/bus
> address of a buffer in user space (supposed this region is already
> locked)?
>
>
> For hints I'd be thankful..
>
> Norbert
> -
> Kernelnewbies: Help each other learn about the Linux kernel.
> Archive: http://mail.nl.linux.org/kernelnewbies/
> IRC Channel: irc.openprojects.net / #kernelnewbies
> Web Page: http://www.kernelnewbies.org/
-
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
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