On Fri, 2013-11-29 at 11:40 -0500, Kevin O'Connor wrote:
On Fri, Nov 29, 2013 at 02:02:02PM +0000, David Woodhouse wrote:
This provides basic debug output on the Quark system, assuming that *something* (i.e. coreboot or UEFI) has set it up in advance for us.
Signed-off-by: David Woodhouse David.Woodhouse@intel.com
I looked briefly at making this part of the CONFIG_DEBUG_SERIAL code, and making that generic enough to handle I/O access *or* MMIO access depending on what's present... but in fact that's probably overkill.
This isn't really limited to Quark; it would work with any 16550 device wired up as MMIO32. But we can expand it as required, I think. No point in starting off with the same functionality as the 5000-odd lines of the Linux kernel's 8250_pci.c.
What do I need to do if called in 32-bit segmented mode? I'm guessing that's not going to work right now...
Do you need debug output from 16bit mode or 32bit segmented mode? The post and boot phases are all 32bit code so typical boot time debugging shouldn't be impacted. Gerd's cbmem debugging code uses this approach.
I can live with that. Perhaps I should make it work in 16-bit mode but *only* if the appropriate BAR has been put in a memory hole below 1MiB.
Now I've got the Quark running... has anyone ever looked at sdhci support... ? :)