Jens Rottmann (JRottmann@LiPPERTembedded.de) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2573
-gerrit
commit 7ffb64659207545a8d59fac812f4e4883755d2bf Author: Jens Rottmann JRottmann@LiPPERTembedded.de Date: Fri Mar 1 19:01:00 2013 +0100
FrontRunner/Toucan-AF: work around AGESA RAM init crashing on reboot
If you try to reset the system with outb(3,0x92), outb(4,0xcf9) or a triple-fault it will instead crash with a messy screen. As the more common outb(0xFE, 0x64) doesn't work with our setup, Linux will crash whenever you ask it to reboot. Closer inspection shows that on a warm boot of Coreboot agesawrapper_amdinitpost() always fails with error code 7. Looks like DDR3 re-init goes wrong somehow. I tried find the reason for this but was unable to. I am convinced this is not board specific but a bug in AGESA.
In the end I had to settle for a workaround: if amdinitpost returns 7 this patch resets the system harder with outb(0x06, 0x0cf9), after that RAM init will succeed. As amdinitpost is early in POST this automatic reset is quick enough not to be noticable.
I'd perfer a real fix, but that's all I have.
Change-Id: I4763254b489f42a135232e45328ecf0d5c4d961a Signed-off-by: Jens Rottmann JRottmann@LiPPERTembedded.de --- src/mainboard/lippert/frontrunner-af/romstage.c | 4 ++++ src/mainboard/lippert/toucan-af/romstage.c | 4 ++++ 2 files changed, 8 insertions(+)
diff --git a/src/mainboard/lippert/frontrunner-af/romstage.c b/src/mainboard/lippert/frontrunner-af/romstage.c index e5b3aeb..14a003a 100644 --- a/src/mainboard/lippert/frontrunner-af/romstage.c +++ b/src/mainboard/lippert/frontrunner-af/romstage.c @@ -113,6 +113,10 @@ void cache_as_ram_main(unsigned long bist, unsigned long cpu_init_detectedx) post_code(0x40); printk(BIOS_DEBUG, "agesawrapper_amdinitpost "); val = agesawrapper_amdinitpost (); + /* Reboots with outb(3,0x92), outb(4,0xcf9) or triple-fault all + * hang, looks like DRAM re-init goes wrong, don't know why. */ + if (val == 7) /* fatal, amdinitenv below is going to hang */ + outb(0x06, 0x0cf9); /* reset system harder instead */ if (val) printk(BIOS_DEBUG, "error level: %x \n", val); else diff --git a/src/mainboard/lippert/toucan-af/romstage.c b/src/mainboard/lippert/toucan-af/romstage.c index 7d11813..fcec303 100644 --- a/src/mainboard/lippert/toucan-af/romstage.c +++ b/src/mainboard/lippert/toucan-af/romstage.c @@ -113,6 +113,10 @@ void cache_as_ram_main(unsigned long bist, unsigned long cpu_init_detectedx) post_code(0x40); printk(BIOS_DEBUG, "agesawrapper_amdinitpost "); val = agesawrapper_amdinitpost (); + /* Reboots with outb(3,0x92), outb(4,0xcf9) or triple-fault all + * hang, looks like DRAM re-init goes wrong, don't know why. */ + if (val == 7) /* fatal, amdinitenv below is going to hang */ + outb(0x06, 0x0cf9); /* reset system harder instead */ if (val) printk(BIOS_DEBUG, "error level: %x \n", val); else