* [PATCH] arm64: dts: amlogic: t7: khadas-vim4: fix memory layout for 8GB RAM
@ 2026-03-06 3:10 Nick Xie
2026-03-06 7:54 ` Ronald Claveau
0 siblings, 1 reply; 2+ messages in thread
From: Nick Xie @ 2026-03-06 3:10 UTC (permalink / raw)
To: neil.armstrong, khilman, martin.blumenstingl, jbrunet
Cc: krzk+dt, robh, conor+dt, linux-amlogic, linux-arm-kernel,
devicetree, linux-kernel, Nick Xie
The Khadas VIM4 features 8GB of LPDDR4X RAM. The previous memory node
mapped a single incorrect region. This caused the kernel to map MMIO
and secure firmware (ATF/TrustZone) memory holes as standard RAM,
leading to an Asynchronous SError Interrupt during early boot
(paging_init) when the kernel attempted to clear those pages.
Fix this by splitting the 8GB memory layout into three separate
regions to properly avoid the memory holes (e.g., 0xe0000000 -
0xffffffff):
- 3.5GB @ 0x000000000
- 3.5GB @ 0x100000000
- 1.0GB @ 0x200000000
Signed-off-by: Nick Xie <nick@khadas.com>
---
arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index 25b478e106451..106eab2b4c2e2 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
@@ -17,7 +17,9 @@ aliases {
memory@0 {
device_type = "memory";
- reg = <0x0 0x0 0x2 0x0>; /* 8 GB */
+ reg = <0x00000000 0x00000000 0x00000000 0xE0000000
+ 0x00000001 0x00000000 0x00000000 0xE0000000
+ 0x00000002 0x00000000 0x00000000 0x40000000>;
};
reserved-memory {
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] arm64: dts: amlogic: t7: khadas-vim4: fix memory layout for 8GB RAM
2026-03-06 3:10 [PATCH] arm64: dts: amlogic: t7: khadas-vim4: fix memory layout for 8GB RAM Nick Xie
@ 2026-03-06 7:54 ` Ronald Claveau
0 siblings, 0 replies; 2+ messages in thread
From: Ronald Claveau @ 2026-03-06 7:54 UTC (permalink / raw)
To: Nick Xie
Cc: krzk+dt, robh, conor+dt, linux-amlogic, linux-arm-kernel,
devicetree, linux-kernel, jbrunet, martin.blumenstingl, khilman,
neil.armstrong
On 3/6/26 4:10 AM, Nick Xie wrote:
> The Khadas VIM4 features 8GB of LPDDR4X RAM. The previous memory node
> mapped a single incorrect region. This caused the kernel to map MMIO
> and secure firmware (ATF/TrustZone) memory holes as standard RAM,
> leading to an Asynchronous SError Interrupt during early boot
> (paging_init) when the kernel attempted to clear those pages.
>
> Fix this by splitting the 8GB memory layout into three separate
> regions to properly avoid the memory holes (e.g., 0xe0000000 -
> 0xffffffff):
> - 3.5GB @ 0x000000000
> - 3.5GB @ 0x100000000
> - 1.0GB @ 0x200000000
>
> Signed-off-by: Nick Xie <nick@khadas.com>
> ---
> arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
> index 25b478e106451..106eab2b4c2e2 100644
> --- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
> @@ -17,7 +17,9 @@ aliases {
>
> memory@0 {
> device_type = "memory";
> - reg = <0x0 0x0 0x2 0x0>; /* 8 GB */
> + reg = <0x00000000 0x00000000 0x00000000 0xE0000000
> + 0x00000001 0x00000000 0x00000000 0xE0000000
> + 0x00000002 0x00000000 0x00000000 0x40000000>;
> };
>
I suggest to remove the leading zeroes here.
> reserved-memory {
^ permalink raw reply [flat|nested] 2+ messages in thread
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