u-boot/doc/README.fsl-ddr
York Sun ebbe11dd36 Add memory test feature for mpc85xx POST.
The memory test is performed after DDR initialization when U-boot stills runs
in flash and cache. On recent mpc85xx platforms, the total memory can be more
than 2GB. To cover whole memory, it needs be mapped 2GB at a time using a
sliding TLB window. After the testing, DDR is remapped with up to 2GB memory
from the lowest address as normal.

If memory test fails, DDR DIMM SPD and DDR controller registers are dumped for
further debugging.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2010-10-20 02:28:00 -05:00

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Table of interleaving modes supported in cpu/8xxx/ddr/
======================================================
+-------------+---------------------------------------------------------+
| | Rank Interleaving |
| +--------+-----------+-----------+------------+-----------+
|Memory | | | | 2x2 | 4x1 |
|Controller | None | 2x1 lower | 2x1 upper | {CS0+CS1}, | {CS0+CS1+ |
|Interleaving | | {CS0+CS1} | {CS2+CS3} | {CS2+CS3} | CS2+CS3} |
+-------------+--------+-----------+-----------+------------+-----------+
|None | Yes | Yes | Yes | Yes | Yes |
+-------------+--------+-----------+-----------+------------+-----------+
|Cacheline | Yes | Yes | No | No, Only(*)| Yes |
| |CS0 Only| | | {CS0+CS1} | |
+-------------+--------+-----------+-----------+------------+-----------+
|Page | Yes | Yes | No | No, Only(*)| Yes |
| |CS0 Only| | | {CS0+CS1} | |
+-------------+--------+-----------+-----------+------------+-----------+
|Bank | Yes | Yes | No | No, Only(*)| Yes |
| |CS0 Only| | | {CS0+CS1} | |
+-------------+--------+-----------+-----------+------------+-----------+
|Superbank | No | Yes | No | No, Only(*)| Yes |
| | | | | {CS0+CS1} | |
+-------------+--------+-----------+-----------+------------+-----------+
(*) Although the hardware can be configured with memory controller
interleaving using "2x2" rank interleaving, it only interleaves {CS0+CS1}
from each controller. {CS2+CS3} on each controller are only rank
interleaved on that controller.
For memory controller interleaving, identical DIMMs are suggested. Software
doesn't check the size or organization of interleaved DIMMs.
The ways to configure the ddr interleaving mode
==============================================
1. In board header file(e.g.MPC8572DS.h), add default interleaving setting
under "CONFIG_EXTRA_ENV_SETTINGS", like:
#define CONFIG_EXTRA_ENV_SETTINGS \
"hwconfig=fsl_ddr:ctlr_intlv=bank" \
......
2. Run u-boot "setenv" command to configure the memory interleaving mode.
Either numerical or string value is accepted.
# disable memory controller interleaving
setenv hwconfig "fsl_ddr:ctlr_intlv=null"
# cacheline interleaving
setenv hwconfig "fsl_ddr:ctlr_intlv=cacheline"
# page interleaving
setenv hwconfig "fsl_ddr:ctlr_intlv=page"
# bank interleaving
setenv hwconfig "fsl_ddr:ctlr_intlv=bank"
# superbank
setenv hwconfig "fsl_ddr:ctlr_intlv=superbank"
# disable bank (chip-select) interleaving
setenv hwconfig "fsl_ddr:bank_intlv=null"
# bank(chip-select) interleaving cs0+cs1
setenv hwconfig "fsl_ddr:bank_intlv=cs0_cs1"
# bank(chip-select) interleaving cs2+cs3
setenv hwconfig "fsl_ddr:bank_intlv=cs2_cs3"
# bank(chip-select) interleaving (cs0+cs1) and (cs2+cs3) (2x2)
setenv hwconfig "fsl_ddr:bank_intlv=cs0_cs1_and_cs2_cs3"
# bank(chip-select) interleaving (cs0+cs1+cs2+cs3) (4x1)
setenv hwconfig "fsl_ddr:bank_intlv=cs0_cs1_cs2_cs3"
Memory controller address hashing
==================================
If the DDR controller supports address hashing, it can be enabled by hwconfig.
Syntax is:
hwconfig=fsl_ddr:addr_hash=true
Memory testing options for mpc85xx
==================================
1. Memory test can be done once U-boot prompt comes up using mtest, or
2. Memory test can be done with Power-On-Self-Test function, activated at
compile time.
In order to enable the POST memory test, CONFIG_POST needs to be
defined in board configuraiton header file. By default, POST memory test
performs a fast test. A slow test can be enabled by changing the flag at
compiling time. To test memory bigger than 2GB, 36BIT support is needed.
Memory is tested within a 2GB window. TLBs are used to map the virtual 2GB
window to physical address so that all physical memory can be tested.
Combination of hwconfig
=======================
Hwconfig can be combined with multiple parameters, for example, on a supported
platform
hwconfig=fsl_ddr:addr_hash=true,ctlr_intlv=cacheline,bank_intlv=cs0_cs1_cs2_cs3