Hi Alex,
On Fri Feb 06, 2009 at 08:05:56 -0800, Alexander Valitov wrote:
I think I have found all L4Linux configuration options related to my task in the following menuconfig’s menu:
L4Linux configuration -> Stub drivers ->
Here they are (I put corresponding variable in parentheses):
[*] Use the rtc server (L4_EXTERNAL_RTC) [ ] Block driver for the generic_blk interface (L4_BLK_DRV) [ ] Block driver for the persistent dataspace interface (L4_PDSPBLK_DRV) [*] Framebuffer driver for l4con and DOpE (input/output) (L4_FB_DRIVER) [ ] Support for the X Window System driver (L4_FB_DRIVER_XF86IF) [ ] Network driver for ORe (L4_ORE_DRV) [*] Pseudo serial driver for console (L4_SERIAL) [*] Serial console support (L4_SERIAL_CONSOLE) [ ] Cons system support (L4_CONS)
Meaning of some of these options is clear for me and some of them isn’t. If I’m right:
- L4_EXTERNAL_RTC option forces L4Linux to use rtc module instead of direct
access to timer hardware.
Yes.
- As you wrote L4_FB_DRIVER compiles in l4fb module into L4Linux, so it
could be used by dope or con server.
Yes.
- L4_ORE_DRV adds stub network driver to L4Linux which uses ore server for
actual access to NIC.
Yes. Or for communication with other Ore clients, like other L4Linuxes.
Other isn’t really clear:
- Help in menuconfig says L4_SERIAL : "Serial type driver used for console". L4_SERIAL_CONSOLE : "you will be able to use the pseudo serial interface as
a system console"
I can’t get the difference between L4_SERIAL and L4_SERIAL_CONSOLE options. Maybe L4_SERIAL is pseudo COM port driver and L4_SERIAL_CONSOLE is module for system console (I mean ttyLv0). Am I right here?
Yes, basically. It's the same difference as e.g. SERIAL_8250 and SERIAL_8250_CONSOLE. I.e. with *_CONSOLE one can use the driver as a system console.
- Another confusing thing is that Wiki says console=ttyLv0 options is to
use 'l4ser' driver for console. But I don’t load such a module (l4ser) and 'console=ttyLv0' option works. What is 'l4ser'? Is it L4 server? If it's not who controls COM port hardware? Is it done by L4 kernel?
l4ser is the serial driver, i.e. the one behind L4_SERIAL.
- You've mentioned "block stub without a real L4 driver". Is it L4_BLK_DRV?
Yes.
Do you have plans to implement the L4 driver?
The old one for real disks hasn't been maintained for ages. Currently there's only one for Fiasco-UX which uses files on the host as disk images. It's in pkg/generic_blk/examples/ux.
- Unfortunately, menuconfig help isn't really comprehensible for me. Could
you please explain, in short, what is L4_CONS?
cons is some text-based console server which isn't in public svn.
- And L4_PDSPBLK_DRV?
It's block driver for a backend server that works on (memory) dataspaces.
- And L4_FB_DRIVER_XF86IF?
The counterpart to Xorg driver in the l4con package.
Adam