From 059f75d501c8a92c6e25b6996e28a81ee6cb0418 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Fri, 11 Nov 2016 08:18:44 +0100 Subject: [PATCH] arm64: mvebu: Restrict memory size to a usable maximum Not all memory is mapped in the MMU. So we need to restrict the memory size so that U-Boot does not try to access it. Also, the internal registers are located at 0xf000.0000 - 0xffff.ffff. Currently only 2GiB are mapped for system memory. This is what we pass to the U-Boot subsystem here. Signed-off-by: Stefan Roese Cc: Nadav Haklai Cc: Neta Zur Hershkovits Cc: Kostya Porotchkin Cc: Omri Itach Cc: Igal Liberman Cc: Haim Boot Cc: Hanna Hawa --- arch/arm/mach-mvebu/arm64-common.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm/mach-mvebu/arm64-common.c b/arch/arm/mach-mvebu/arm64-common.c index 1fc2ff2..8f02655 100644 --- a/arch/arm/mach-mvebu/arm64-common.c +++ b/arch/arm/mach-mvebu/arm64-common.c @@ -17,6 +17,23 @@ DECLARE_GLOBAL_DATA_PTR; /* + * Not all memory is mapped in the MMU. So we need to restrict the + * memory size so that U-Boot does not try to access it. Also, the + * internal registers are located at 0xf000.0000 - 0xffff.ffff. + * Currently only 2GiB are mapped for system memory. This is what + * we pass to the U-Boot subsystem here. + */ +#define USABLE_RAM_SIZE 0x80000000 + +ulong board_get_usable_ram_top(ulong total_size) +{ + if (gd->ram_size > USABLE_RAM_SIZE) + return USABLE_RAM_SIZE; + + return gd->ram_size; +} + +/* * On ARMv8, MBus is not configured in U-Boot. To enable compilation * of the already implemented drivers, lets add a dummy version of * this function so that linking does not fail. -- 2.7.4