Re: [LinuxBIOS] PATCH: lx car that returns from disable_car

[Peter Stuge]

On Tue, Jan 08, 2008 at 04:54:29PM -0700, Marc Jones wrote:
> How about this?
> Marc
> Add hlt() back into the die() function and update the comments.
>
> Signed-off-by: Marc Jones

Acked-by: Peter Stuge
> Index: LinuxBIOSv3/lib/console.c
>
> --- LinuxBIOSv3.orig/lib/console.c	2008-01-08 16:32:28.000000000 -0700
> +++ LinuxBIOSv3/lib/console.c	2008-01-08 16:48:52.000000000 -0700
> @@ -83,30 +83,37 @@
>  }
>
> /**
> Halt and loop due to a fatal error.
> There have been several iterations of this function.
> Halt and loop due to a fatal error.
> There have been several iterations of this function.
> The first simply did a hlt(). Doing a hlt() can make jtag debugging
> very difficult as one can not break into a hlt instruction on some CPUs.
> Second was to do a console_tx_byte of a NULL character.
> A number of concerns were raised about doing this idea.
> Third idea was to do an inb from port 0x80, the POST port. That design
> makes us very CPU-specific.
> very difficult as one can not break into a hlt instruction on some CPUs.
> Second was to do a console_tx_byte of a NULL character.
> A number of concerns were raised about doing this idea.
> Third idea was to do an inb from port 0x80, the POST port. That design
> makes us very CPU-specific.
> The fourth idea was just POSTING the same
> code over and over. That would erase the most recent POST code,
> hindering diagnosis.
> code over and over. That would erase the most recent POST code,
> hindering diagnosis.
> For now, for lack of a good alternative,
> we will continue to call console_tx_byte. We call with a NULL since
> it will clear any FIFOs in the path and won't clutter up the output,
> since NULL doesn't print a visible character on most terminal
> emulators.
> For now, for lack of a better alternative,
> we will call console_tx_byte ten times and then halt.
> Some CPU JTAG debbuggers might have problems but it is the right thing
> to do. We call with a NULL since it will clear any FIFOs in the path and
> won't clutter up the output, since NULL doesn't print a visible character
> on most terminal emulators.
> @param str A string to print for the error
> */
>
> void die(const char *str)
>  {
> int i;
> printk(BIOS_EMERG, str);
> while (1)
> console_tx_byte(0, (void *)0);
> while (1) {
> for (i = 0; i < 10; i++)
> 	console_tx_byte(0, (void *)0);
> hlt();
> }
>
> }