Re: [PATCH 4/7] ARM: zynqmp: add update handler

[Michael Tretter <m.tretter@pengutronix.de>]

On Thu, 24 Jun 2021 15:34:33 +0200, Ahmad Fatoum wrote:
> On 24.06.21 15:24, Michael Tretter wrote:
> > On Thu, 24 Jun 2021 12:52:58 +0200, Ahmad Fatoum wrote:
> >> On 24.06.21 12:23, Michael Tretter wrote:
> >>> The ZynqMP boots from an SDHCI device by reading a boot.bin file from
> >>> the FAT16/32 partition, which is the first partition in the MBR.
> >>>
> >>> The update handler copies a boot.bin image to this partition, which
> >>> might be board specific.
> >>
> >> Is barebox the boot.bin or is that a separate first stage bootloader?
> > 
> > Both. The boot.bin contains at least the first stage bootloader, TF-A, and
> > Barebox. You cannot boot a "standalone" Barebox image on the ZynqMP.
> > 
> > I also documented this in the zynqmp documentation as part of this patch
> > series.
> 
> I saw that after writing the mail here. Thanks for clarifying.
> 
> > 
> > Michael
> > 
> >>
> >>>
> >>> Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
> >>> ---
> >>>  arch/arm/mach-zynqmp/Makefile                 |  1 +
> >>>  .../arm/mach-zynqmp/include/mach/zynqmp-bbu.h | 21 ++++++++
> >>>  arch/arm/mach-zynqmp/zynqmp-bbu.c             | 48 +++++++++++++++++++
> >>>  3 files changed, 70 insertions(+)
> >>>  create mode 100644 arch/arm/mach-zynqmp/include/mach/zynqmp-bbu.h
> >>>  create mode 100644 arch/arm/mach-zynqmp/zynqmp-bbu.c
> >>>
> >>> diff --git a/arch/arm/mach-zynqmp/Makefile b/arch/arm/mach-zynqmp/Makefile
> >>> index 14b8a4e46b87..e24a43c0d59f 100644
> >>> --- a/arch/arm/mach-zynqmp/Makefile
> >>> +++ b/arch/arm/mach-zynqmp/Makefile
> >>> @@ -1,3 +1,4 @@
> >>>  # SPDX-License-Identifier: GPL-2.0-or-later
> >>>  obj-y += firmware-zynqmp.o
> >>>  obj-y += zynqmp.o
> >>> +obj-$(CONFIG_BAREBOX_UPDATE) += zynqmp-bbu.o
> >>> diff --git a/arch/arm/mach-zynqmp/include/mach/zynqmp-bbu.h b/arch/arm/mach-zynqmp/include/mach/zynqmp-bbu.h
> >>> new file mode 100644
> >>> index 000000000000..8502791ee0f7
> >>> --- /dev/null
> >>> +++ b/arch/arm/mach-zynqmp/include/mach/zynqmp-bbu.h
> >>> @@ -0,0 +1,21 @@
> >>> +/* SPDX-License-Identifier: GPL-2.0-only */
> >>> +/*
> >>> + * Copyright (C) 2020 Michael Tretter <m.tretter@pengutronix.de>
> >>> + */
> >>> +#ifndef __MACH_ZYNQMP_BBU_H
> >>> +#define __MACH_ZYNQMP_BBU_H
> >>> +
> >>> +#include <bbu.h>
> >>> +
> >>> +#ifdef CONFIG_BAREBOX_UPDATE
> >>> +int zynqmp_bbu_register_handler(const char *name, char *devicefile,
> >>> +				unsigned long flags);
> >>> +#else
> >>> +static int zynqmp_bbu_register_handler(const char *name, char *devicefile,
> >>> +				       unsigned long flags)
> >>> +{
> >>> +	return 0;
> >>> +};
> >>> +#endif
> >>> +
> >>> +#endif /* __MACH_ZYNQMP_BBU_H */
> >>> diff --git a/arch/arm/mach-zynqmp/zynqmp-bbu.c b/arch/arm/mach-zynqmp/zynqmp-bbu.c
> >>> new file mode 100644
> >>> index 000000000000..d1197c01dc41
> >>> --- /dev/null
> >>> +++ b/arch/arm/mach-zynqmp/zynqmp-bbu.c
> >>> @@ -0,0 +1,48 @@
> >>> +// SPDX-License-Identifier: GPL-2.0-only
> >>> +/*
> >>> + * Copyright (C) 2020 Michael Tretter <m.tretter@pengutronix.de>
> >>> + */
> >>> +
> >>> +#include <common.h>
> >>> +#include <libfile.h>
> >>> +#include <mach/zynqmp-bbu.h>
> >>> +
> >>> +static int zynqmp_bbu_handler(struct bbu_handler *handler,
> >>> +		struct bbu_data *data)
> >>> +{
> >>> +	int ret = 0;
> >>> +
> >>> +	ret = bbu_confirm(data);
> >>> +	if (ret)
> >>> +		return ret;
> >>> +
> >>> +	ret = copy_file(data->imagefile, data->devicefile, 1);
> >>> +	if (ret < 0) {
> >>> +		pr_err("update failed: %s", strerror(-ret));
> >>> +		return ret;
> >>> +	}
> 
> EFI also registers an barebox update handler for a file: /boot/EFI/BOOT/BOOTx64.EFI,
> but there apparently bbu_register_std_file_update suffices.
> 
> Did you check if that would work for you as well?
> 
> It's still a good idea to have a zynqmp specific wrapper for bbu_register_std_file_update,
> but I am not sure you need to duplicate the copy_file stuff.

I didn't know about the handler and haven't checked this. If this can work,
I'll sent another patch to replace the copy_file stuff with use of the
existing functions.

> 
> Also, this seems SD-specific. I assume eMMC would boot from boot partitions?
> If so, zynqmp_bbu_register_sd_handler may be a more apt name.

No, eMMC boot partitions are not supported by the ROM code. The handler is the
same for SD and eMMC.

Michael

> 
> 
> >>> +
> >>> +	return ret;
> >>> +}
> >>> +
> >>> +int zynqmp_bbu_register_handler(const char *name, char *devicefile,
> >>> +		unsigned long flags)
> >>> +{
> >>> +	struct bbu_handler *handler;
> >>> +	int ret = 0;
> >>> +
> >>> +	if (!name || !devicefile)
> >>> +		return -EINVAL;
> >>> +
> >>> +	handler = xzalloc(sizeof(*handler));
> >>> +	handler->name = name;
> >>> +	handler->devicefile = devicefile;
> >>> +	handler->flags = flags;
> >>> +	handler->handler = zynqmp_bbu_handler;
> >>> +
> >>> +	ret = bbu_register_handler(handler);
> >>> +	if (ret)
> >>> +		free(handler);
> >>> +
> >>> +	return ret;
> >>> +}

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