[RFC PATCH] riscv: dts: nezha-d1: Add memory

[RFC PATCH] riscv: dts: nezha-d1: Add memory

[Evan Green]

Add memory info for the D1 Nezha, which seems to be required for it to
boot with the stock firmware. Note that this hardcodes 1GB, which is
not technically correct as they also make models with different amounts
of RAM. Is the firmware supposed to populate this?

Signed-off-by: Evan Green <evan@rivosinc.com>

---

 arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts b/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts
index 4ed33c1e7c9c..6aba68cf5541 100644
--- a/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts
+++ b/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts
@@ -32,6 +32,12 @@ / {
 	model = "Allwinner D1 Nezha";
 	compatible = "allwinner,d1-nezha", "allwinner,sun20i-d1";
 
+	// FIXME: this is temporary.
+	memory@40000000 {
+		device_type = "memory";
+		reg = <0x40000000 0x40000000>; /* 1 GB */
+	};
+
 	aliases {
 		ethernet0 = &emac;
 		ethernet1 = &xr829;
-- 
2.25.1

Re: [RFC PATCH] riscv: dts: nezha-d1: Add memory

[Conor Dooley]

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On Fri, Mar 31, 2023 at 11:27:27AM -0700, Evan Green wrote:
> Add memory info for the D1 Nezha, which seems to be required for it to
> boot with the stock firmware. Note that this hardcodes 1GB, which is
> not technically correct as they also make models with different amounts
> of RAM.

> Is the firmware supposed to populate this?

Yup. Samuel intentionally did it this way:
https://lore.kernel.org/linux-riscv/8a2194bf-93bd-de4d-8d39-0cd72aabb0a9@sholland.org/

Since I don't like using the firmware provided stuff to more easily
test I do this in my u-boot boot script:

tftp 0x54000000 d1-fitImage.fit
bootm start 0x54000000
bootm loados 0x54000000
bootm ramdisk;
bootm prep;
fdt memory 0x40000000 0x20000000
bootm go;

Hope either of the above are helpful,
Conor.

> 
> Signed-off-by: Evan Green <evan@rivosinc.com>
> 
> ---
> 
>  arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts b/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts
> index 4ed33c1e7c9c..6aba68cf5541 100644
> --- a/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts
> +++ b/arch/riscv/boot/dts/allwinner/sun20i-d1-nezha.dts
> @@ -32,6 +32,12 @@ / {
>  	model = "Allwinner D1 Nezha";
>  	compatible = "allwinner,d1-nezha", "allwinner,sun20i-d1";
>  
> +	// FIXME: this is temporary.
> +	memory@40000000 {
> +		device_type = "memory";
> +		reg = <0x40000000 0x40000000>; /* 1 GB */
> +	};
> +
>  	aliases {
>  		ethernet0 = &emac;
>  		ethernet1 = &xr829;
> -- 
> 2.25.1
> 

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Re: [RFC PATCH] riscv: dts: nezha-d1: Add memory

[Evan Green]

On Fri, Mar 31, 2023 at 11:39 AM Conor Dooley <conor@kernel.org> wrote:
>
> On Fri, Mar 31, 2023 at 11:27:27AM -0700, Evan Green wrote:
> > Add memory info for the D1 Nezha, which seems to be required for it to
> > boot with the stock firmware. Note that this hardcodes 1GB, which is
> > not technically correct as they also make models with different amounts
> > of RAM.
>
> > Is the firmware supposed to populate this?
>
> Yup. Samuel intentionally did it this way:
> https://lore.kernel.org/linux-riscv/8a2194bf-93bd-de4d-8d39-0cd72aabb0a9@sholland.org/
>
> Since I don't like using the firmware provided stuff to more easily
> test I do this in my u-boot boot script:
>
> tftp 0x54000000 d1-fitImage.fit
> bootm start 0x54000000
> bootm loados 0x54000000
> bootm ramdisk;
> bootm prep;
> fdt memory 0x40000000 0x20000000
> bootm go;
>
> Hope either of the above are helpful,
> Conor.

Ah, I see, thanks for the pointers. I've got whatever firmware came
with the "dd and go" Fedora image I found on the internet somewhere,
which doesn't seem to do the memory node population for me. I've been
hesitant to rebuild the firmware as I don't want to break the Fedora
"safe OS", and if there's a way to get mired in some build
environment, I seem to have a nose for finding it.

I'll probably just keep the patch locally in my tree, and if I'm
forced to update the firmware for some other reason I'll try removing
it.

-Evan