Sven Schnelle (svens@stackframe.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/615
-gerrit
commit 8c64567a2309229fba3a891fe15b0d55da2ff0b0 Author: Sven Schnelle svens@stackframe.org Date: Thu Feb 9 21:05:20 2012 +0100
i5000: halt second BSP
If both FSBs on i5000 are equipped with CPU packages, one CPU from each package is elected as BSP. To prevent races between both BSPs, hlt the second BSP.
Change-Id: I6bfcb17d34e9f028280acff1694309e37307ec21 Signed-off-by: Sven Schnelle svens@stackframe.org --- src/northbridge/intel/i5000/Makefile.inc | 1 + src/northbridge/intel/i5000/halt_second_bsp.S | 29 +++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/src/northbridge/intel/i5000/Makefile.inc b/src/northbridge/intel/i5000/Makefile.inc index a5623c0..5e75159 100644 --- a/src/northbridge/intel/i5000/Makefile.inc +++ b/src/northbridge/intel/i5000/Makefile.inc @@ -19,3 +19,4 @@
driver-y += northbridge.c romstage-y += raminit.c udelay.c +cpu_incs += src/northbridge/intel/i5000/halt_second_bsp.S diff --git a/src/northbridge/intel/i5000/halt_second_bsp.S b/src/northbridge/intel/i5000/halt_second_bsp.S new file mode 100644 index 0000000..4d52224 --- /dev/null +++ b/src/northbridge/intel/i5000/halt_second_bsp.S @@ -0,0 +1,29 @@ + /* Save BIST result */ + + movl %eax, %ebp + + /* Read the semaphore register of i5000 (BOFL0). + If it returns zero, it means there was already + another read by another CPU */ + + movl $0x800080c0, %eax + movw $0xcf8, %dx + outl %eax, %dx + + addw $4, %dx + inl %dx, %eax + cmp $0, %eax + jne 1f + + /* degrade BSP to AP */ + mov $0x1b, %ecx + rdmsr + andl $(~0x100), %eax + wrmsr + + cli + hlt +tloop: jmp tloop + +1: /* Restore BIST */ + mov %ebp, %eax