[U-Boot] [PATCH v2 00/11] SPL support for RISC-V

[Rick Chen]

Hi Lukas

>
> Hi Rick,
>
> On Thu, 2019-08-01 at 11:32 +0800, Rick Chen wrote:
> > Hi Lukas
> >
> > > > From: Lukas Auer [mailto:lukas.auer at aisec.fraunhofer.de]
> > > > Sent: Sunday, July 28, 2019 11:57 PM
> > > > To: u-boot at lists.denx.de
> > > > Cc: Atish Patra; Rick Jian-Zhi Chen(陳建志); Bin Meng; Sagar Kadam; Alistair
> > > > Francis; Anup Patel; Troy Benjegerdes; Lukas Auer; Abel Vesa; Alex Kiernan;
> > > > Alex Marginean; Alexander Graf; Andreas Dannenberg; Andrew F. Davis; Anup
> > > > Patel; Anup Patel; Atish Patra; Chris Packham; Eugeniu Rosca; Heiko Schocher;
> > > > Heinrich Schuchardt; Jagan Teki; Jean-Jacques Hiblot; Jens Wiklander; Joe
> > > > Hershberger; Kever Yang; Lokesh Vutla; Lukasz Majewski; Marek Vasut; Marek
> > > > Vasut; Marek Vasut; Markus Klotzbuecher; Michal Simek; Paul Burton; Peng
> > > > Fan; Philipp Tomsich; Philippe Reynes; Ryder Lee; Shawn Guo; Simon Glass;
> > > > Simon Goldschmidt; Stefan Roese; Stefano Babic; Tien Fong Chee; Vignesh R;
> > > > Weijie Gao; Ye Li
> > > > Subject: [PATCH v2 00/11] SPL support for RISC-V
> > > >
> > > > This series adds support for SPL to RISC-V U-Boot. Images can be booted via
> > > > OpenSBI (FW_DYNAMIC firmware) or by directly jumping to them. In the
> > > > former case, OpenSBI and U-Boot proper are bundled as a FIT image and made
> > > > available to U-Boot SPL. Currently, only the QEMU board enables U-Boot SPL
> > > > with a dedicated configuration. It uses RAM as SPL boot device.
> > > >
> > > > On many RISC-V CPUs, the device tree is provided to U-Boot by the first stage
> > > > bootloader. This requires changes to U-Boot SPL (patches 1,
> > > > 2 and 3), which modify the behavior on other boards as well.
> > > >
> > > > To test this series, OpenSBI has to be compiled first. The fw_dynamic.bin
> > > > binary must be copied into the U-Boot root directory.
> > > > Alternatively, the location of the binary can be specified with the OPENSBI
> > > > environment variable. U-Boot can then be build as normal using the
> > > > configuration qemu-riscv64_spl_defconfig for 64-bit builds or
> > > > qemu-riscv32_spl_defconfig for 32-bit builds. The outputs from the build
> > > > process are the U-Boot SPL binary (spl/u-boot-spl.bin) and the U-Boot FIT
> > > > image (u-boot.itb) containing U-Boot proper and OpenSBI.
> > > >
> > > > U-Boot can be run in QEMU with the following command.
> > > >
> > > > qemu-system-riscv64 -nographic -machine virt -kernel spl/u-boot-spl \
> > > >       -device loader,file=u-boot.itb,addr=0x80200000
> > > >
> >
> > Great job !
> >
>
> Thank you!
>
> > I also try to run the spl flow on ax25-ae350 platform.
> > But encounter some problems. I am still debugging.
> >
> > Following is the error message:
> > :
> > U-Boot SPL 2019.07-10574-ge6ef7ec-dirty (Aug 01 2019 - 10:09:45 +0800)
> > Trying to boot from RAM
> >
> > U-Boot 2019.07-10574-ge6ef7ec-dirty (Aug 01 2019 - 10:09:45 +0800)
> >
> > DRAM:  exception code: 5 , Load access fault , epc 1212654 , ra 1200ffe
> > ### ERROR ### Please RESET the board ###
> >
> > Do you have some comments ?
> >
>
> It is difficult to judge without the exact configuration. Is your
> current git tree available somewhere?

No, it is not available yet.
And you don't have the ax25-ae350 board, it is still in vain if the
git tree is available.

>
> The error is quite strange, because it already booted U-Boot proper. So
> the error does not happen in code, which has been directly modified by
> this series. Perhaps it is trying to initialize something twice (once
> in SPL and again in U-Boot proper)? Can you check at what location the
> error occurs?

I found that the exception occurred in get_ram_size() of ax25-ae350.c
when it try to load the memory address 0x10000.
But the access of 0x20000 is ok.

I try to mark the get_ram_size() and do not execute it, U-Boot proper
can boot successfully as below:

U-Boot SPL 2019.07-10574-ge6ef7ec-dirty (Aug 02 2019 - 16:07:54 +0800)
Trying to boot from RAM

U-Boot 2019.07-10574-ge6ef7ec-dirty (Aug 02 2019 - 16:07:54 +0800)
DRAM:  1 GiB
Flash: 64 MiB
MMC:   mmc at f0e00000: 0
Loading Environment from SPI Flash... SF: Detected mx25u1635e with
page size 256 Bytes, erase size 4 KiB, total 2 MiB
*** Warning - bad CRC, using default environment
In:    serial at f0300000
Out:   serial at f0300000
Err:   serial at f0300000
Net:   no alias for ethernet0
Warning: mac at e0100000 (eth0) using random MAC address - 36:13:4d:06:b8:fd
eth0: mac at e0100000
Hit any key to stop autoboot:  0
RISC-V #

So I tried to trace openSBI and found the BANNER of openSBI was not printed.
Is it correct ?

Any idea about why the access of memory address(0x10000) will fail ?
I guess it seem relative to pmp configuration.
I am still tracing it ...

Thanks
Rick