board/b4qds:Add support of 2 stage NAND boot-loader
Add support of 2 stage NAND boot loader using SPL framework.
here, PBL initialise the internal SRAM and copy SPL(160KB). This further
initialise DDR using SPD and environment and copy u-boot(768 KB) from NAND to DDR.
Finally SPL transer control to u-boot.
Initialise/create followings required for SPL framework
- Add spl.c which defines board_init_f, board_init_r
- update tlb and ddr accordingly
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/doc/README.b4860qds b/doc/README.b4860qds
index 3da77d9..eada0c7 100644
--- a/doc/README.b4860qds
+++ b/doc/README.b4860qds
@@ -328,3 +328,39 @@
On Linux the interfaces are renamed as:
. eth2 -> fm1-gb2
. eth3 -> fm1-gb3
+
+NAND boot with 2 Stage boot loader
+----------------------------------
+PBL initialise the internal SRAM and copy SPL(160KB) in SRAM.
+SPL further initialise DDR using SPD and environment variables and copy
+u-boot(768 KB) from flash to DDR.
+Finally SPL transer control to u-boot for futher booting.
+
+SPL has following features:
+ - Executes within 256K
+ - No relocation required
+
+ Run time view of SPL framework during boot :-
+ -----------------------------------------------
+ Area | Address |
+-----------------------------------------------
+ Secure boot | 0xFFFC0000 (32KB) |
+ headers | |
+ -----------------------------------------------
+ GD, BD | 0xFFFC8000 (4KB) |
+ -----------------------------------------------
+ ENV | 0xFFFC9000 (8KB) |
+ -----------------------------------------------
+ HEAP | 0xFFFCB000 (30KB) |
+ -----------------------------------------------
+ STACK | 0xFFFD8000 (22KB) |
+ -----------------------------------------------
+ U-boot SPL | 0xFFFD8000 (160KB) |
+ -----------------------------------------------
+
+NAND Flash memory Map on B4860 and B4420QDS
+------------------------------------------
+ Start End Definition Size
+0x000000 0x0FFFFF u-boot 1MB
+0x140000 0x15FFFF u-boot env 128KB
+0x1A0000 0x1BFFFF FMAN Ucode 128KB