[PATCH 2/4] spl: Make UFS available for SPL builds

[Alexey Charkov]

Hi Neil,

Thanks for your review!

On Thu, Dec 11, 2025 at 10:36 AM Neil Armstrong
<neil.armstrong at linaro.org> wrote:
>
> Hi,
>
> On 12/10/25 21:10, Alexey Charkov wrote:
> > Add minimal infrastructure to build SPL images with support for UFS
> > storage devices. This also pulls in SCSI support and charset functions,
> > which are dependencies of the UFS code.
> >
> > With this, only a fixed offset is supported for loading the next image,
> > which should be specified in CONFIG_SPL_UFS_RAW_U_BOOT_SECTOR as the
> > number of 4096-byte sectors into the UFS block device.
> >
> > Signed-off-by: Alexey Charkov <alchark at gmail.com>
> > ---
> >   MAINTAINERS                |  1 +
> >   arch/arm/include/asm/spl.h |  1 +
> >   common/spl/Kconfig         | 16 +++++++++++++++
> >   common/spl/Makefile        |  1 +
> >   common/spl/spl_ufs.c       | 49 ++++++++++++++++++++++++++++++++++++++++++++++
> >   drivers/Makefile           |  1 +
> >   drivers/scsi/Makefile      |  3 +++
> >   lib/Makefile               |  1 +
> >   8 files changed, 73 insertions(+)
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index c9853f409920..c58805a724b9 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -1860,6 +1860,7 @@ M:      Neil Armstrong <neil.armstrong at linaro.org>
> >   M:  Bhupesh Sharma <bhupesh.linux at gmail.com>
> >   M:  Neha Malcom Francis <n-francis at ti.com>
> >   S:  Maintained
> > +F:   common/spl/spl_ufs.c
> >   F:  drivers/ufs/
> >
> >   UPL
> > diff --git a/arch/arm/include/asm/spl.h b/arch/arm/include/asm/spl.h
> > index ee79a19c05c9..dd462ea6ad82 100644
> > --- a/arch/arm/include/asm/spl.h
> > +++ b/arch/arm/include/asm/spl.h
> > @@ -30,6 +30,7 @@ enum {
> >       BOOT_DEVICE_XIP,
> >       BOOT_DEVICE_BOOTROM,
> >       BOOT_DEVICE_SMH,
> > +     BOOT_DEVICE_UFS,
> >       BOOT_DEVICE_NONE
> >   };
> >   #endif
> > diff --git a/common/spl/Kconfig b/common/spl/Kconfig
> > index a43271671648..aa198ee44a3f 100644
> > --- a/common/spl/Kconfig
> > +++ b/common/spl/Kconfig
> > @@ -1608,6 +1608,22 @@ config SPL_THERMAL
> >         automatic power-off when the temperature gets too high or low. Other
> >         devices may be discrete but connected on a suitable bus.
> >
> > +config SPL_UFS_SUPPORT
> > +     bool "Support loading from UFS"
> > +     select SPL_LOAD_BLOCK
> > +     help
> > +       Enable support for UFS in SPL. This allows
> > +       use of UFS devices such as hard drives and flash drivers for
> > +       loading U-Boot.
> > +
> > +config SPL_UFS_RAW_U_BOOT_SECTOR
> > +     hex "Address on the UFS to load U-Boot from"
> > +     depends on SPL_UFS_SUPPORT
> > +     default 0x800 if ARCH_ROCKCHIP
> > +     help
> > +       Address on the block device to load U-Boot from，
> > +       Units: UFS sectors (1 sector = 4096 bytes).
>
> The UFS are usually configured with multiple LUNs, so I would expect to at least
> have the LUN parameter in case we use the sector address to load the payload.

Indeed. Rockchip's tools don't offer a direct way to access
non-default LUNs, which makes it a bit tricky to test booting from
anything other than LUN 0 (apart from using a fully booted system with
its full-blown drivers to write to other LUNs). I'll test and add the
extra Kconfig selector for the LUN.

> >   config SPL_WATCHDOG
> >       bool "Support watchdog drivers"
> >       imply SPL_WDT if !HW_WATCHDOG
> > diff --git a/common/spl/Makefile b/common/spl/Makefile
> > index 4c9482bd3096..e18f3cf09484 100644
> > --- a/common/spl/Makefile
> > +++ b/common/spl/Makefile
> > @@ -37,6 +37,7 @@ obj-$(CONFIG_$(PHASE_)DFU) += spl_dfu.o
> >   obj-$(CONFIG_$(PHASE_)SPI_LOAD) += spl_spi.o
> >   obj-$(CONFIG_$(PHASE_)RAM_SUPPORT) += spl_ram.o
> >   obj-$(CONFIG_$(PHASE_)USB_SDP_SUPPORT) += spl_sdp.o
> > +obj-$(CONFIG_$(PHASE_)UFS_SUPPORT) += spl_ufs.o
> >   endif
> >
> >   obj-$(CONFIG_$(PHASE_)UPL) += spl_upl.o
> > diff --git a/common/spl/spl_ufs.c b/common/spl/spl_ufs.c
> > new file mode 100644
> > index 000000000000..3a5fcd4ed7a8
> > --- /dev/null
> > +++ b/common/spl/spl_ufs.c
> > @@ -0,0 +1,49 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * (C) Copyright 2025 Alexey Charkov <alchark at gmail.com>
> > + */
> > +
> > +#include <spl.h>
> > +#include <spl_load.h>
> > +#include <scsi.h>
> > +#include <errno.h>
> > +#include <image.h>
> > +#include <linux/compiler.h>
> > +#include <log.h>
> > +
> > +static ulong h_spl_load_read(struct spl_load_info *load, ulong off,
> > +                          ulong size, void *buf)
>
> What a weird function name, please rename to spl_ufs_load_read

Ack. I grabbed it wholesale from spl_mmc.c - but I agree that it's not
exactly descriptive :) Will rename in v2.

Best regards,
Alexey