diff options
| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2004-11-18 22:53:42 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-11-18 22:53:42 -0800 |
| commit | 5b6c534999948ad1032adc44fab17a6e01d0a29f (patch) | |
| tree | 627aaa205737e1b8663a340dbfb6c2886c50c8bc /Documentation | |
| parent | fa3f122042c31da97267a7d357a8274d3c199d22 (diff) | |
| download | history-5b6c534999948ad1032adc44fab17a6e01d0a29f.tar.gz | |
[PATCH] early uart console support
This adds an early polled-mode "uart" console driver, based on Andi Kleen's
early_printk work.
The difference is that this locates the UART device directly by its MMIO or
I/O port address, so we don't have to make assumptions about how ttyS
devices will be named. After the normal serial driver starts, we try to
locate the matching ttyS device and start a console there.
Sample usage:
console=uart,io,0x3f8
console=uart,mmio,0xff5e0000,115200n8
If the baud rate isn't specified, we peek at the UART to figure it out.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 0ef66ae82467d6..2b76f4eb732f69 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -312,8 +312,24 @@ running once the system is up. condev= [HW,S390] console device conmode= - console= [KNL] Output console - Console device and comm spec (speed, control, parity). + console= [KNL] Output console device and options. + + tty<n> Use the virtual console device <n>. + + ttyS<n>[,options] + Use the specified serial port. The options are of + the form "bbbbpn", where "bbbb" is the baud rate, + "p" is parity ("n", "o", or "e"), and "n" is bits. + Default is "9600n8". + + See also Documentation/serial-console.txt. + + uart,io,<addr>[,options] + uart,mmio,<addr>[,options] + Start an early, polled-mode console on the 8250/16550 + UART at the specified I/O port or MMIO address, + switching to the matching ttyS device later. The + options are the same as for ttyS, above. cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] |