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authorUwe Hermann <uwe@hermann-uwe.de>2008-11-18 12:02:03 +0000
committerUwe Hermann <uwe@hermann-uwe.de>2008-11-18 12:02:03 +0000
commit8ab91d875b3572a1c9b50e2035edf996aa8727da (patch)
tree4b39465003c0038871594488926526e306fad907 /src/northbridge/intel
parent8c0702b89b2e71f29f828c54c67f2f6bff89d5c1 (diff)
downloadcoreboot-8ab91d875b3572a1c9b50e2035edf996aa8727da.tar.xz
i810: Add some more comments, and especially add a list of tested BUFF_SC
values for different DIMM configurations. This should be converted to a table or code later on and actually be used for BUFF_SC. Many thanks to Elia Yehuda <z4ziggy@gmail.com> for testing and collecting the table entries. Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de> Acked-by: Uwe Hermann <uwe@hermann-uwe.de> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3759 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src/northbridge/intel')
-rw-r--r--src/northbridge/intel/i82810/i82810.h19
-rw-r--r--src/northbridge/intel/i82810/raminit.c49
2 files changed, 46 insertions, 22 deletions
diff --git a/src/northbridge/intel/i82810/i82810.h b/src/northbridge/intel/i82810/i82810.h
index e70b35c9a6..94993ec540 100644
--- a/src/northbridge/intel/i82810/i82810.h
+++ b/src/northbridge/intel/i82810/i82810.h
@@ -30,17 +30,16 @@
/*
* PCI Configuration Registers.
*
- * Any addresses between 0x00 and 0xff not listed below are reserved and
+ * Any addresses between 0x50 and 0xff not listed below are reserved and
* should not be touched.
*/
-/* TODO: Descriptions. */
-#define GMCHCFG 0x50
-#define PAM 0x51
-#define DRP 0x52
-#define DRAMT 0x53
-#define FDHC 0x58
+#define GMCHCFG 0x50 /* GMCH Configuration */
+#define PAM 0x51 /* Programmable Attributes */
+#define DRP 0x52 /* DRAM Row Population */
+#define DRAMT 0x53 /* DRAM Timing */
+#define FDHC 0x58 /* Fixed DRAM Hole Control */
#define SMRAM 0x70 /* System Management RAM Control */
-#define MISSC 0x72
-#define MISSC2 0x80
-#define BUFF_SC 0x92
+#define MISSC 0x72 /* Miscellaneous Control */
+#define MISSC2 0x80 /* Miscellaneous Control 2 */
+#define BUFF_SC 0x92 /* System Memory Buffer Strength Control */
diff --git a/src/northbridge/intel/i82810/raminit.c b/src/northbridge/intel/i82810/raminit.c
index 67addf6caf..23d45c924f 100644
--- a/src/northbridge/intel/i82810/raminit.c
+++ b/src/northbridge/intel/i82810/raminit.c
@@ -47,13 +47,13 @@ Macros and definitions.
#endif
/* DRAMT[7:5] - SDRAM Mode Select (SMS). */
-#define RAM_COMMAND_SELF_REFRESH 0x0 /* IE disable refresh */
-#define RAM_COMMAND_NORMAL 0x1 /* Normal refresh, 15.6us/11.7us for 100/133MHz */
-#define RAM_COMMAND_NORMAL_FR 0x2 /* Fast refresh, 7.8us/5.85us for 100/133MHz */
-#define RAM_COMMAND_NOP 0x4
-#define RAM_COMMAND_PRECHARGE 0x5
-#define RAM_COMMAND_MRS 0x6
-#define RAM_COMMAND_CBR 0x7
+#define RAM_COMMAND_SELF_REFRESH 0x0 /* Disable refresh */
+#define RAM_COMMAND_NORMAL 0x1 /* Refresh: 15.6/11.7us for 100/133MHz */
+#define RAM_COMMAND_NORMAL_FR 0x2 /* Refresh: 7.8/5.85us for 100/133MHz */
+#define RAM_COMMAND_NOP 0x4 /* NOP command */
+#define RAM_COMMAND_PRECHARGE 0x5 /* All bank precharge */
+#define RAM_COMMAND_MRS 0x6 /* Mode register set */
+#define RAM_COMMAND_CBR 0x7 /* CBR */
/*-----------------------------------------------------------------------------
SDRAM configuration functions.
@@ -98,6 +98,9 @@ static void do_ram_command(const struct mem_controller *ctrl, uint32_t command,
DIMM-independant configuration functions.
-----------------------------------------------------------------------------*/
+/*
+ * Set DRP - DRAM Row Population Register (Device 0).
+ */
static void spd_set_dram_size(const struct mem_controller *ctrl,
uint32_t row_offset)
{
@@ -209,13 +212,35 @@ static void set_dram_timing(const struct mem_controller *ctrl)
// pci_write_config8(ctrl->d0, DRAMT, 0x00);
}
+/*
+ * TODO: BUFF_SC needs to be set according to the DRAM tech (x8, x16,
+ * or x32), but the datasheet doesn't list all the detaisl. Currently, it
+ * needs to be pulled from the output of 'lspci -xxx Rx92'.
+ *
+ * Common results (tested on actual hardware) are:
+ *
+ * (DRP: c = 128MB dual sided, d = 128MB single sided, f = 256MB dual sided)
+ *
+ * BUFF_SC TOM DRP DIMM0 DIMM1
+ * ----------------------------------------------------------------------------
+ * 0x3356 128MB 0x0c 128MB dual-sided -
+ * 0xcc56 128MB 0xc0 - 128MB dual-sided
+ * 0x77da 128MB 0x0d 128MB single-sided -
+ * 0xddda 128MB 0xd0 - 128MB single-sided
+ * 0x0001 256MB 0xcc 128MB dual-sided 128MB dual-sided
+ * 0x55c6 256MB 0xdd 128MB single-sided 128MB single-sided
+ * 0x4445 256MB 0xcd 128MB single-sided 128MB dual-sided
+ * 0x1145 256MB 0xdc 128MB dual-sided 128MB single-sided
+ * 0x3356 256MB 0x0f 256MB dual-sided -
+ * 0xcc56 256MB 0xf0 - 256MB dual-sided
+ * 0x0001 384MB 0xcf 256MB dual-sided 128MB dual-sided
+ * 0x0001 384MB 0xfc 128MB dual-sided 256MB dual-sided
+ * 0x1145 384MB 0xdf 256MB dual-sided 128MB single-sided
+ * 0x4445 384MB 0xfd 128MB single-sided 256MB dual-sided
+ * 0x0001 512MB 0xff 256MB dual-sided 256MB dual-sided
+ */
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
- */
pci_write_config16(ctrl->d0, BUFF_SC, 0x77da);
}