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1. Drivers Allwinner H3 Download
2. Drivers Allwinner H3 Driver
3. Drivers Allwinner H3 Manual
4. Drivers Allwinner H3 Free

Allwinner A64: 32 KiB: 0x10000: sp=0x47FE0: Sizes larger than 32 KiB are rejected by the BROM. Exactly 32 KiB is fine, as verified by writing a special pattern at the end of the SPL and checking it in the SRAM. Allwinner H3: 32 KiB: 0x00000: sp=0x0F7DC: Sizes larger than 32 KiB are rejected by the BROM. The answer is yes, it can be done, but you need a bit of knowledge about compiling kernel modules. I made it on an Orange PI PC (Allwinner H3) to test my armsoc drivers and it worked, although Mali-400 MP2 embedded into H3 was quite slow. Based on the Allwinner H5 datasheet and the pinctrl driver of the backward-compatible H3 this introduces the pin multiplex assignments for the H5 SoC.

Porting NetBSD to Allwinner H3 SoCs

A new SUNXI evbarm kernel has appeared recently in NetBSD -current with support for boards based on the Allwinner H3 system on a chip (SoC). The H3 SoC is a quad-core Cortex-A7 SoC designed primarily for set-top boxes, but has managed to find its way into many single-board computers (SBC). This is one of the first evbarm ports built from the ground up with device tree support, which helps us to use a single kernel config to support many different boards.

To get these boards up and running, first we need to deal with low-level startup code. For the SUNXI kernel this currently lives in sys/arch/evbarm/sunxi/. The purpose of this code is fairly simple; initialize the boot CPU and initialize the MMU so we can jump to the kernel. The initial MMU configuration needs to cover a few things -- early on we need to be able to access the kernel, UART debug console, and the device tree blob (DTB) passed in from U-Boot. We wrap the kernel in a U-Boot header that claims to be a Linux kernel; this is no accident! This tells U-Boot to use the Linux boot protocol when loading the kernel, which ensures that the DTB (loaded by U-Boot) is processed and passed to us in r2.

Drivers Allwinner H3 Download

Once the CPU and MMU are ready, we jump to the generic ARM FDT implementation of initarm in sys/arch/evbarm/fdt/fdt_machdep.c. The first thing this code does is validate and relocate the DTB data. After it has been relocated, we compare the compatible property of the root node in the device tree with the list of ARM platforms compiled into the kernel. The Allwinner sunxi platform code lives in sys/arch/arm/sunxi/sunxi_platform.c. The sunxi platform code provides SoC-specific versions of code needed early at boot. We need to know how to initialize the debug console, spin up application CPUs, reset the board, etc.

Drivers Allwinner H3 Driver

Instead of writing H3-specific code for spinning up application CPUs, I took advantage of U-Boot's Power State Coordination Interface implementation. A psci(4) driver was added and the allwinner,sun8i-h3 platform code was modified to use this code to start up all processors.

Drivers Allwinner H3 Manual

With a bit of luck, we're now booting and enumerating devices. Apart from a few devices, almost nothing works yet as we are missing a driver for the CCU. The CCU in the Allwinner H3 SoC controls PLLs and most of the clock generation, division, muxing, and gating. Since there are many similarities between Allwinner SoCs, I opted to write generic CCU code and then SoC-specific frontends. The resulting code lives in sys/arch/arm/sunxi/; generic code as sunxi_ccu.c and H3-specific code in sun8i_h3_ccu.c.

Now we have a CCU driver, we can attach a com(4) and have a valid console device.

Drivers Allwinner H3 Free

After this, it's a matter of writing drivers and/or adapting existing code to attach to fdtbus based on the bindings used in the DTB. For cases where we had a compatible driver in the old Allwinner port, I opted to make a copy of the code and FDT-ize it. A few reasons for this -- 1) the old drivers have CCU-specific code with per-SoC ifdefs scattered throughout, 2) I didn't want to break existing kernels, and 3) long term goal is to move the SoCs supported by the old code over to the new code (this process has already started with the Allwinner A31 port).

So what do we get out of this? This is a step towards being able to ship a GENERIC evbarm kernel. I developed the H3 port on two boards, the NanoPi NEO and Orange Pi Plus 2E, but since then users on port-arm@ have been reporting success on many other H3 boards, all from a single kernel config. In addition, I've added support for other Allwinner SoCs (sun8i-a83t, sun6i-a31) to the kernel and have tested booting the same kernel across all 3 SoCs.

Orange Pi Plus 2E boot log is below.