[PATCH 1/4] riscv: spl: Introduce SPL_OPENSBI_OS_BOOT

Wed Dec 14 02:54:40 CET 2022

On Wed, Dec 14, 2022 at 08:49:03AM +0800, Rick Chen wrote:
> Hi Tom,
> 
> > On Tue, Dec 13, 2022 at 10:06:50AM +0800, Rick Chen wrote:
> > > > On Mon, Dec 12, 2022 at 03:49:10PM +0800, Rick Chen wrote:
> > > > > > On 12/7/22 01:23, Rick Chen wrote:
> > > > > > > In RISC-V, it only provide normal mode booting currently.
> > > > > > > To speed up the booting process, here provide SPL_OPENSBI_OS_BOOT
> > > > > > > to achieve this feature which will be call Fast-Boot mode. By
> > > > > >
> > > > > > Can you name this something different. We already have something called
> > > > > > fastboot in-tree (the Android-derived protocol) and there's a Microsoft
> > > > > > technology called fastboot (some kind of hibernation). "OS Boot" isn't
> > > > > > very specific either, since we (almost always) boot an OS. Maybe "Eagle
> > > > > > mode" by analogy to Falcon mode, which lets SPL directly boot an OS.
> > > > >
> > > > > I think fast boot is a behavior which shall be interpreted widely but
> > > > > not proprietary.
> > > > > Or maybe I can  rename it as RISC-V Fast Boot to distinguish them.
> > > > >
> > > > > >
> > > > > > (Is this substantially different from falcon mode anyway?)
> > > > >
> > > > > Please see the explanations to Tom.
> > > > >
> > > > > >
> > > > > > > enabling SPL_OPENSBI_OS_BOOT, it will generate linux.itb instead
> > > > > > > of default u-boot.itb after compiling. It initializes memory with
> > > > > > > the U-Boot SPL at the first stage, just like what a regular booting
> > > > > > > process (i.e. Normal Boot) does in the beginning. Instead of jumping
> > > > > > > to the U-Boot proper from OpenSBI before booting Linux Kernel, the
> > > > > > > Fast Boot process jumps directly to Linux Kernel to gain shorter
> > > > > > > booting time.
> > > > > > >
> > > > > > > Signed-off-by: Rick Chen <rick at andestech.com>
> > > > > > > ---
> > > > > > >   common/spl/Kconfig       | 14 ++++++++++++++
> > > > > > >   common/spl/spl_fit.c     |  3 ++-
> > > > > > >   common/spl/spl_opensbi.c | 25 ++++++++++++-------------
> > > > > > >   3 files changed, 28 insertions(+), 14 deletions(-)
> > > > > > >
> > > > > > > diff --git a/common/spl/Kconfig b/common/spl/Kconfig
> > > > > > > index 05181bdba3..8805aba1b7 100644
> > > > > > > --- a/common/spl/Kconfig
> > > > > > > +++ b/common/spl/Kconfig
> > > > > > > @@ -1509,6 +1509,20 @@ config SPL_OPENSBI_SCRATCH_OPTIONS
> > > > > > >         Options passed to fw_dynamic, for example SBI_SCRATCH_NO_BOOT_PRINTS or
> > > > > > >         SBI_SCRATCH_DEBUG_PRINTS.
> > > > > > >
> > > > > > > +config SPL_OPENSBI_OS_BOOT
> > > > > >
> > > > > > Please use the same name for the config as for the description.
> > > > > >
> > > > > > > +     bool "openSBI Fast Boot"
> > > > > > > +     depends on SPL_OPENSBI
> > > > > > > +     help
> > > > > > > +       Enable this openSBI can jump to Linux Kernel directly.
> > > > > >
> > > > > > Can you put some of the explanation from the commit message here?
> > > > >
> > > > > OK, I will move some messages here from commit messages.
> > > > >
> > > > > >
> > > > > > > +
> > > > > > > +config SPL_OPENSBI_FIT_NAME
> > > > > > > +     string "SPL openSBI fit image name"
> > > > > > > +     depends on SPL_OPENSBI
> > > > > > > +     default "linux.itb" if SPL_OPENSBI_OS_BOOT
> > > > > > > +     default "u-boot.itb"
> > > > > > > +     help
> > > > > > > +       This will help to generate different fit name accordingly.
> > > > > >
> > > > > > Why not SPL_FS_LOAD_PAYLOAD_NAME?
> > > > > >
> > > > > > It looks like the code changes below do not use these configs. Can you
> > > > > > move them to the next patch so it is clearer that they are for binman?
> > > > >
> > > > > I have saw this config, but it does't support SPL_RAM but only for filesystem
> > > > > That is why I don't leverage it.
> > > > >
> > > > > I can prepare a patch as below if no other concerns:
> > > > >
> > > > > config SPL_FS_LOAD_PAYLOAD_NAME
> > > > > string "File to load for U-Boot from the filesystem"
> > > > > depends on SPL_FS_EXT4 || SPL_FS_FAT || SPL_FS_SQUASHFS || SPL_RAM
> > > > > default "tispl.bin" if SYS_K3_SPL_ATF
> > > > > default "u-boot.itb" if SPL_LOAD_FIT
> > > > > default "linux.itb" if SPL_OPENSBI_OS_BOOT
> > > > > default "u-boot.img"
> > > > > help
> > > > >   Filename to read to load U-Boot when reading from filesystem.
> > > >
> > > > But in the case you have it's for the output name, and not at all about
> > > > what's being loaded from a filesystem yes? This shouldn't be a "SPL_.."
> > >
> > > For SPL_RAM purpose,
> > > it is just an output name to distinguish normal boot (u-boot.itb) and
> > > fast boot (linux.itb) indeed.
> > >
> > > But for SPL_OPENSBI_OS_BOOT && SPL_MMC && SPL_FAT this combination,
> > > it can help to load linux.itb automatically from SD card.
> >
> > What part of the world is looking for the file named by
> > SPL_FS_LOAD_PAYLOAD_NAME ? (and this is related to what I just sent out,
> > asking about the boot flow)
> 
> In the following commit, CONFIG_SPL_FS_LOAD_PAYLOAD_NAME has been
> moved to Kconfig from ax25-ae350.h
> That is why I try to add this change to load u-boot.itb or linux.itb
> from SD card here
> 
> commit 4a11e34bc9c0f3818f3e847ac51c82d1c9bbb807
> Author: Tom Rini <trini at konsulko.com>
> Date:   Fri May 13 17:12:35 2022 -0400
> 
>     Convert CONFIG_SPL_FS_LOAD_PAYLOAD_NAME et al to Kconfig
> 
> ...
> 
> +++ b/include/configs/ax25-ae350.h
> @@ -11,10 +11,6 @@
>  #define CONFIG_SPL_MAX_SIZE            0x00100000
>  #define CONFIG_SPL_BSS_START_ADDR      0x04000000
>  #define CONFIG_SPL_BSS_MAX_SIZE                0x00100000
> -
> -#ifdef CONFIG_SPL_MMC
> -#define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME                "u-boot.itb"
> -#endif

Yes, I made a best guess "what do I need to do to have zero size change"
migration of that option, along with most others. So, sorry, my original
question remains.  In real world usage, what is using that name? The
regular usage here is that SPL knows to read from FAT (or similar) that
name as a hard-coded default.

-- 
Tom
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