On Tue, 2018-09-04 at 17:31 +0800, Bin Meng wrote:
Hi Lukas,
On Tue, Sep 4, 2018 at 5:39 AM Auer, Lukas lukas.auer@aisec.fraunhofer.de wrote:
On Thu, 2018-08-30 at 00:54 -0700, Bin Meng wrote:
This adds QEMU RISC-V 'virt' board target support, with the hope of helping people easily test U-Boot on RISC-V.
The QEMU virt machine models a generic RISC-V virtual machine with support for the VirtIO standard networking and block storage devices. It has CLINT, PLIC, 16550A UART devices in addition to VirtIO and it also uses device-tree to pass configuration information to guest software. It implements RISC-V privileged architecture spec v1.10.
Both 32-bit and 64-bit builds are supported. Support is pretty much preliminary, only booting to U-Boot shell with the UART driver on a single core. Booting Linux is not supported yet.
For your information and to avoid duplicate work, I am working on a patch set that improves RISC-V support in u-boot. I am currently able to boot Linux on a multi-core setup in QEMU, but they are not quite ready to submit yet.
This is great! My next step is to work on virtio driver support in U-Boot as qemu-riscv virt machine has these devices but we don't have corresponding drivers in U-Boot. Then I will try to boot Linux after that. Good to hear you already boot Linux with qemu-riscv! Have you already supported virtio drivers in your port? If yes, I will just hold on and wait for your patch series :-)
Hi Bin,
Support for the virtio devices would be great! I don't support them in my port, I can only boot a kernel image from RAM. I only have a driver for the clint0 (core local interrupt controller), which I need for software interrupts to other cores and as a timer. Software interrupts also work over the supervisor binary interface (SBI), which allows u-boot to run in supervisor mode with bbl running in machine mode to handle the SBI calls.
Thank you for your patches, it's great to see better support for RISC-V in u-boot! I will add a few comments based on what I have learned so far from working with u-boot on RISC-V.
It's a good start. RISC-V is pretty new and needs more developers :-)
Exactly :)
Thanks, Lukas