From 092da485c7e685745b6e6f9ab5540fb002046201 Mon Sep 17 00:00:00 2001 From: Prabhakar Kushwaha Date: Thu, 28 May 2015 14:54:11 +0530 Subject: [PATCH] armv8/ls2085a: Update SoC README for DDR layout Update SoC README to provide details of - Memory regions - Memory used by MC and Debug server Signed-off-by: Bhupesh Sharma Signed-off-by: Prabhakar Kushwaha Reviewed-by: York Sun --- arch/arm/cpu/armv8/fsl-lsch3/README | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/arch/arm/cpu/armv8/fsl-lsch3/README b/arch/arm/cpu/armv8/fsl-lsch3/README index 37f07fbb76..3c15479315 100644 --- a/arch/arm/cpu/armv8/fsl-lsch3/README +++ b/arch/arm/cpu/armv8/fsl-lsch3/README @@ -9,6 +9,31 @@ Freescale LayerScape with Chassis Generation 3 This architecture supports Freescale ARMv8 SoCs with Chassis generation 3, for example LS2085A. +DDR Layout +============ +Entire DDR region splits into two regions. + - Region 1 is at address 0x8000_0000 to 0xffff_ffff. + - Region 2 is at 0x80_8000_0000 to the top of total memory, + for example 16GB, 0x83_ffff_ffff. + +All DDR memory is marked as cache-enabled. + +When MC and Debug server is enabled, they carve 512MB away from the high +end of DDR. For example, if the total DDR is 16GB, it shrinks to 15.5GB +with MC and Debug server enabled. Linux only sees 15.5GB. + +The reserved 512MB layout looks like + + +---------------+ <-- top/end of memory + | 256MB | debug server + +---------------+ + | 256MB | MC + +---------------+ + | ... | + +MC requires the memory to be aligned with 512MB, so even debug server is +not enabled, 512MB is reserved, not 256MB. + Flash Layout ============ -- 2.39.5