Hi Lukas, On Tue, Nov 13, 2018 at 10:45 PM Auer, Lukas <lukas.a...@aisec.fraunhofer.de> wrote: > > Hi Bin, > > On Tue, 2018-11-13 at 00:21 -0800, Bin Meng wrote: > > This adds U-Boot syscon driver for RISC-V Core Local Interruptor > > (CLINT). The CLINT block holds memory-mapped control and status > > registers associated with software and timer interrupts. > > > > 3 APIs are provided for U-Boot to implement Supervisor Binary > > Interface (SBI) as defined by the RISC-V privileged architecture > > spec v1.10. > > > > Signed-off-by: Bin Meng <bmeng...@gmail.com> > > --- > > Would it make sense to also abstract the functions provided by the > CLINT more? The reason why I am asking is because the CLINT is > (unfortunately) not specified as part of RISC-V. It is developing into > a de facto standard since other platforms are following SiFive's > implementation, but there is nothing that would prevent them from > implementing something else. >
I think your observation is correct about CLINT. Rick, does Andes's RISC-V processor also follow SiFive's CLINT model? > Two immediate examples I can think of would be mtime and the IPI > implementation. Many SoC vendors will likely already have a suitable > timer IP block for mtime. I can imagine that they would choose to re- > use their memory map instead of following that of the CLINT. > For the IPI implementation there is already an alternative, the SBI. If > U-Boot should be able to run in supervisor mode, it would be helpful to > support both the SBI and the CLINT interface. > I am not sure I followed you here. This driver provides 3 APIs: riscv_send_ipi() is for IPI, and the other 2 are for mtime/mtimecmp. > So what we would need is some kind of API for the functionality > provided by the CLINT. For the multi-core support (I will try to send > out a series soon) I am re-using the IRQ uclass ID (it is only used in > arch code) to define a irq-uclass for RISC-V, which handles everything > with IPIs. The CLINT0 and SBI are then just different driver > implementing the uclass. > > This is just an idea right now, what do you think? > Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
