Patch set updated for coreboot: f0bd464 AMD Geode LX: add get_top_of_ram()

[Christian Gmeiner]

Christian Gmeiner ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3322

-gerrit

commit f0bd4644a8255ba6feb8f33ce863ce46dd6504f1
Author: Christian Gmeiner 
Date:   Wed May 29 11:20:37 2013 +0200

AMD Geode LX: add get_top_of_ram()

get_top_of_ram() is needed for EARLY_CBMEM_INIT. We are reading the
    RCONF_DEFAULT_MSR (0x1808) msr. It contains SYSTOP [27:8], which
    is the top of system memory that is available for general processor
    use.

Here is a short calucation demo:
    CPU_RCONF_DEFAULT (1808): 0x25FFFC02:0x10FFDF00

0x25FFFC0210FFDF00 & 0xFFFFF00 = 0xFFDF00
    0xFFDF00 << 8 = 0xFFDF0000

Change-Id: Iadde6aab85ab2adc526f1ef3c5fc22e0f5b06d51
    Signed-off-by: Christian Gmeiner 
---
 src/northbridge/amd/lx/raminit.c | 7 +++++++
 src/northbridge/amd/lx/raminit.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/src/northbridge/amd/lx/raminit.c b/src/northbridge/amd/lx/raminit.c
index 9a53e9e..db9fa61 100644
--- a/src/northbridge/amd/lx/raminit.c
+++ b/src/northbridge/amd/lx/raminit.c
@@ -774,3 +774,10 @@ static void sdram_enable(int controllers, const struct mem_controller *ctrl)
    print_info("RAM DLL lock\n");

}
+
+unsigned long get_top_of_ram(void)
+{
+	msr_t msr = rdmsr(CPU_RCONF_DEFAULT);
+	uint32_t systop = (msr.lo & 0xFFFFF00) << 8;
+	return (unsigned long)systop;
+}
diff --git a/src/northbridge/amd/lx/raminit.h b/src/northbridge/amd/lx/raminit.h
index 3d4d4c6..8c11525 100644
--- a/src/northbridge/amd/lx/raminit.h
+++ b/src/northbridge/amd/lx/raminit.h
@@ -28,5 +28,6 @@ struct mem_controller {
 };

void sdram_initialize(int controllers, const struct mem_controller *ctrl);
+unsigned long get_top_of_ram(void);

#endif