Messages in this thread |  | | Date | Mon, 12 Feb 2001 15:17:04 -0800 (PST) | From | Ivan Passos <> | Subject | Re: LILO and serial speeds over 9600 |
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On Mon, 12 Feb 2001, Scott Laird wrote: > > On 12 Feb 2001, H. Peter Anvin wrote: > > > > Just checked my own code, and SYSLINUX does indeed support 115200 (I > > changed this to be a 32-bit register ages ago, apparently.) Still > > doesn't answer the question "why"... all I think you do is increase > > the risk for FIFO overrun and lost characters (flow control on a boot > > loader console is vestigial at the best.) > > It's simple -- we want the kernel to have its serial console running at > 115200, and we don't want to have to change speeds to talk to the > bootloader.
Exactly.
Then HPA may ask: but why do you want to run the serial console at 115200?? The answer is simple: because we can (or more precisely, because the HW can ;).
If the hardware is supposed to support 115.2Kbps, why can't / shouldn't we use it?? Remember, this is not a modem connection, there is no compression involved, both sides are running 115.2Kbps, so there should NOT be a risk for FIFO overruns (unless you have buggy hardware). And in this case, you can then decrease your baud rate. But at least you have the _option_! :)
> Some boot processes, particularaly fsck, can be *REALLY* > verbose on screwed up systems. I've seen systems take hours to run fsck, > even on small filesystems, simply because they were blocking on a 9600 bps > console.
This is true!!
Another one (not as critical as the fsck though): when compiling the kernel, sometimes the kernel compilation is done, but the console output isn't finished yet (I'm serious).
Later, Ivan
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