On 11 Aug 2023, at 03:01, Guo Ren <guoren@xxxxxxxxxx> wrote: > > On Fri, Aug 11, 2023 at 8:42 AM Jessica Clarke <jrtc27@xxxxxxxxxx> wrote: >> >> On 10 Aug 2023, at 17:33, Jisheng Zhang <jszhang@xxxxxxxxxx> wrote: >>> >>> On Tue, Aug 08, 2023 at 09:29:58AM -0400, guoren@xxxxxxxxxx wrote: >>>> From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> >>>> >>>> Add detailed information about thead,reset-sample driver, and improve >>>> usage documentation. >>>> >>>> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> >>>> Signed-off-by: Guo Ren <guoren@xxxxxxxxxx> >>>> --- >>>> docs/platform/thead-c9xx.md | 87 ++++++++++++++++++++++++++++--------- >>>> 1 file changed, 67 insertions(+), 20 deletions(-) >>>> >>>> diff --git a/docs/platform/thead-c9xx.md b/docs/platform/thead-c9xx.md >>>> index 8bb9e91f1a9b..fe05fc5bb85a 100644 >>>> --- a/docs/platform/thead-c9xx.md >>>> +++ b/docs/platform/thead-c9xx.md >>>> @@ -1,8 +1,8 @@ >>>> -T-HEAD C9xx Series Processors >>>> -============================= >>>> +T-HEAD Processors >>>> +================= >>>> >>>> -The **C9xx** series processors are high-performance RISC-V architecture >>>> -multi-core processors with AI vector acceleration engine. >>>> +T-HEAD provides high-performance RISC-V architecture multi-core >>>> +processors with AI vector acceleration engine. >>>> >>>> For more details, refer [T-HEAD.CN](https://www.t-head.cn/) >>>> >>>> @@ -12,15 +12,75 @@ To build the platform-specific library and firmware images, provide the >>>> Platform Options >>>> ---------------- >>>> >>>> -The *T-HEAD C9xx* does not have any platform-specific compile options >>>> +The *T-HEAD CPU* does not have any platform-specific compile options >>>> because it uses generic platform. >>>> >>>> ``` >>>> CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic /usr/bin/make >>>> ``` >>>> >>>> -The *T-HEAD C9xx* DTB provided to OpenSBI generic firmwares will usually have >>>> -"riscv,clint0", "riscv,plic0", "thead,reset-sample" compatible strings. >>>> +The *T-HEAD CPU* DTB provided to OpenSBI generic firmwares will usually have >>>> +"thead,reset-sample" compatible strings. The "thead,reset-sample" is a T-HEAD >>>> +custom driver for the SMP system bootup; the single-core system doesn't need >>>> +it. >>>> + >>>> +T-HEAD Fdt Reset Driver Introduction >>>> +------------------------------------ >>>> + >>>> +Every T-HEAD CPU provides a reset control signal and reset address signals. >>>> + - Reset address signal determines CPU where to start up. >>>> + - Reset control signal releases CPU from reset state and begins to execute >>>> + at reset address. >>>> + >>>> +Many vendors would gather these signals into SoC control registers. These >>>> +register designs are similar but with different base addresses and bits >>>> +definitions. We only provide standard opensbi, Linux binaries, and jtag gdbinit >>>> +script to simplify Linux booting at the FPGA stage. The fdt reset driver helps >>>> +users bring up their SMP system quickly with the below settings: >>> >>> +DT maintainers and DT list. >>> >>> I can submit a dt-binding for this if DT maintainers agree with below >>> properties. Could you please help review? >> >> I thought this was already discussed on the OpenSBI list 2 months ago, >> and received pretty negative feedback. > Yes, we want to correct all DT grammar & compile problems, and make it > legal first and try again. I thought every vendor has their own choice > of how to deliver their hardware support. The motivation of this > driver is to ease the delivery of T-HEAD CPU cores on different > platforms; people only need three things: jtag_init_script & opensbi & > linux_Image, then they could boot on their own FPGA prototype > platform, and they needn't prepare any software stuff, all the generic > binaries could be directly used. The th1520 could be a good example > for them. That's why we consistently push this thing. What’s changed to make people say yes rather than no this time? I for one will not give positive feedback for self-modifying code in my firmware (outside of the necessary self-relocation at startup before the PMP is enabled). Jess
