From 009049e728d6a7529c853accb3de169fd17b6d5c Mon Sep 17 00:00:00 2001 From: Andrei Gherzan Date: Wed, 24 Jul 2019 16:10:40 +0100 Subject: raspberrypi4-64.conf: Limit RAM to 3G The PCI controller on the Raspberry Pi 4 acts as a DMA controller and can only address the first 3Gb[1] of the memory space. On 32bit this was addressed by implementing bouncing buffers[2] but this currently has no support for arm64. In order to have working USB, as a workaround, we limit the ram to 3G. Fixes #446 [1] https://github.com/raspberrypi/linux/issues/3093 [2] https://github.com/raspberrypi/linux/blob/rpi-4.19.y/drivers/pci/controller/pcie-brcmstb-bounce.c Signed-off-by: Andrei Gherzan --- conf/machine/raspberrypi4-64.conf | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/conf/machine/raspberrypi4-64.conf b/conf/machine/raspberrypi4-64.conf index e308577..2455172 100644 --- a/conf/machine/raspberrypi4-64.conf +++ b/conf/machine/raspberrypi4-64.conf @@ -31,6 +31,6 @@ KERNEL_IMAGETYPE_UBOOT ?= "Image" KERNEL_IMAGETYPE_DIRECT ?= "Image" KERNEL_BOOTCMD ?= "booti" -RPI_EXTRA_CONFIG ?= "\n# Force arm in 64bit mode. See: https://github.com/raspberrypi/firmware/issues/1193.\narm_64bit=1" +RPI_EXTRA_CONFIG ?= "\n# Force arm in 64bit mode. See: https://github.com/raspberrypi/firmware/issues/1193.\narm_64bit=1\n\n# Limit RAM to 3G. See: https://github.com/raspberrypi/linux/issues/3093\ntotal_mem=3072" ARMSTUB ?= "armstub8-gic.bin" -- cgit v1.2.3-54-g00ecf