armv8/ls2085ardb: Enable NAND SPL support

[platform/kernel/u-boot.git] / arch / arm / cpu / armv8 / fsl-lsch3 / README

diff --git a/arch/arm/cpu/armv8/fsl-lsch3/README b/arch/arm/cpu/armv8/fsl-lsch3/README
index 4f36e2a..37f07fb 100644 (file)
--- a/arch/arm/cpu/armv8/fsl-lsch3/README
+++ b/arch/arm/cpu/armv8/fsl-lsch3/README
@@ -95,3 +95,54 @@ mcboottimeout:       MC boot timeout in milliseconds. If this variable is not defined
 
 mcmemsize:     MC DRAM block size. If this variable is not defined, the value
                CONFIG_SYS_LS_MC_DRAM_BLOCK_MIN_SIZE will be assumed.
+
+Booting from NAND
+-------------------
+Booting from NAND requires two images, RCW and u-boot-with-spl.bin.
+The difference between NAND boot RCW image and NOR boot image is the PBI
+command sequence. Below is one example for PBI commands for QDS which uses
+NAND device with 2KB/page, block size 128KB.
+
+1) CCSR 4-byte write to 0x00e00404, data=0x00000000
+2) CCSR 4-byte write to 0x00e00400, data=0x1800a000
+The above two commands set bootloc register to 0x00000000_1800a000 where
+the u-boot code will be running in OCRAM.
+
+3) Block Copy: SRC=0x0107, SRC_ADDR=0x00020000, DEST_ADDR=0x1800a000,
+BLOCK_SIZE=0x00014000
+This command copies u-boot image from NAND device into OCRAM. The values need
+to adjust accordingly.
+
+SRC            should match the cfg_rcw_src, the reset config pins. It depends
+               on the NAND device. See reference manual for cfg_rcw_src.
+SRC_ADDR       is the offset of u-boot-with-spl.bin image in NAND device. In
+               the example above, 128KB. For easy maintenance, we put it at
+               the beginning of next block from RCW.
+DEST_ADDR      is fixed at 0x1800a000, matching bootloc set above.
+BLOCK_SIZE     is the size to be copied by PBI.
+
+RCW image should be written to the beginning of NAND device. Example of using
+u-boot command
+
+nand write <rcw image in memory> 0 <size of rcw image>
+
+To form the NAND image, build u-boot with NAND config, for example,
+ls2085aqds_nand_defconfig. The image needed is u-boot-with-spl.bin.
+The u-boot image should be written to match SRC_ADDR, in above example 0x20000.
+
+nand write <u-boot image in memory> 200000 <size of u-boot image>
+
+With these two images in NAND device, the board can boot from NAND.
+
+Another example for RDB boards,
+
+1) CCSR 4-byte write to 0x00e00404, data=0x00000000
+2) CCSR 4-byte write to 0x00e00400, data=0x1800a000
+3) Block Copy: SRC=0x0119, SRC_ADDR=0x00080000, DEST_ADDR=0x1800a000,
+BLOCK_SIZE=0x00014000
+
+nand write <rcw image in memory> 0 <size of rcw image>
+nand write <u-boot image in memory> 80000 <size of u-boot image>
+
+Notice the difference from QDS is SRC, SRC_ADDR and the offset of u-boot image
+to match board NAND device with 4KB/page, block size 512KB.