[coreboot] v2[PATCH]RCA RM4100 i82830 support

[Corey Osgood]

On Tue, 2008-02-26 at 02:27 +0100, Peter Stuge wrote:
> On Mon, Feb 25, 2008 at 04:31:15PM -0500, joe at smittys.pointclark.net wrote:
> ..
> > >tv-out
> > 
> > Dis-reguard the last patch, this is the real one. A e100 kernel driver  
> > developer helped me figure out that the ethernet was an irq routing  
> > issue, fixed! It is working great now:-)))
> 
> Good news!
> 
> Do you have any idea about the TV out?
> 
> Also see the comments below:
> 
> 
> > +++ src/northbridge/intel/i82830/raminit.c	(revision 0)
> ..
> > +static void set_dram_timing(const struct mem_controller *ctrl)
> > +{
> > +	/* Set the value for DRAM Timing Register */
> > +	/* TODO: Configure the value according to SPD values. */
> > +	pci_write_config32(ctrl->d0, DRT, 0x00000010);
> > +}
> > +
> > +static void set_dram_buffer_strength(const struct mem_controller *ctrl)
> > +{
> > +	/* TODO: This needs to be set according to the DRAM tech
> > +	 * (x8, x16, or x32). Argh, Intel provides no docs on this!
> > +	 * Currently, it needs to be pulled from the output of
> > +	 * lspci -xxx Rx92
> > +	*/
> > +
> > +	/* Set the value for System Memory Buffer Strength Control Registers */
> > +	pci_write_config32(ctrl->d0, BUFF_SC, 0xFC9B491B);
> > +}
> 
> How about these two TODOs? In the second case I think the comment
> refers to running the command under the factory BIOS - in that case
> it would be good to clarify that.

The memory on the rm4100 is onboard. There's a header for a memory slot,
but there's more unknown hardware missing to hook that up. The only
version with memory slots is the Thomson IP1001 (somewhat rare,
essentially the same board with a different branding), and perhaps some
internal RCA prototypes. This info is courtesy of Joe and his site ;)

That said, the BUFF_SC registers are the same deal as on the i810, the
explanation in the datasheet isn't specific or clear about how to set
them. The rest of the registers are fairly simple to set, but without
the ability to try other memory sticks or with real spd data, it might
look right on the rm4100, but fail in practice.

> > +static void sdram_enable(int controllers, const struct mem_controller *ctrl)
> > +{
> ..
> > +	/* 4. Mode register set. Wait two memory cycles. */
> > +	/* TODO: Set offset according to DRT values */
> > +	PRINT_DEBUG("RAM Enable 4: Mode register set\r\n");
> > +	do_ram_command(ctrl, RAM_COMMAND_MRS, 0x1d0);
> 
> Can this be done?

Same deal as above. I can put together another patch later, and put the
code in ifdefs with a note to that effect.

-Corey

> > +++ targets/rca/rm4100/Config.lb	(revision 0)
> ..
> > +romimage "fallback"
> > +	option USE_FALLBACK_IMAGE = 1
> > +	option FALLBACK_SIZE = ROM_SIZE
> > +	option COREBOOT_EXTRA_VERSION = "_RM4100"
> > +#	payload /etc/hosts
> 
> This last line makes no sense so I would remove it before the commit.
> 
> 
> //Peter
>