Re: [PATCH] cmd: sf: Support unaligned flash updates with 'sf update'

From: Simon Glass <sjg@chromium.org>
To: Frieder Schrempf <frieder@fris.de>
Cc: U-Boot Mailing List <u-boot@lists.denx.de>,
	Heiko Thiery <heiko.thiery@gmail.com>,
	Michael Walle <michael@walle.cc>,
	Frieder Schrempf <frieder.schrempf@kontron.de>,
	 Bin Meng <bmeng.cn@gmail.com>,
	Jagan Teki <jagan@amarulasolutions.com>,
	 Pratyush Yadav <p.yadav@ti.com>,
	Sean Anderson <seanga2@gmail.com>
Subject: Re: [PATCH] cmd: sf: Support unaligned flash updates with 'sf update'
Date: Thu, 30 Sep 2021 23:03:47 -0600	[thread overview]
Message-ID: <CAPnjgZ3q1Bvm3fdN8yrAJiz+OpHL5bsSvvZhzm0mM+Gb51xOSw@mail.gmail.com> (raw)
In-Reply-To: <20210930161926.2748887-1-frieder@fris.de>

Hi Frieder,

On Thu, 30 Sept 2021 at 10:20, Frieder Schrempf <frieder@fris.de> wrote:
>
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>
> Currently 'sf update' supports only offsets that are aligned to the
> erase block size of the serial flash. Unaligned offsets result in
> something like:
>
> => sf update ${kernel_addr_r} 0x400 ${filesize}
> device 0 offset 0x400, size 0x11f758
> SPI flash failed in erase step

<insert motivation for patch here>

>
> In order to support unaligned updates, we simply read the first full
> block and check only the requested part of the block for changes. If
> necessary, the block is erased, the first (unchanged) part of the block
> is written back together with the second part of the block (updated data).
>
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  cmd/sf.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
>

Regards,
Simon