Re: [PATCH 6/6] nvmem: u-boot-env: post process "ethaddr" env variable

[Rafał Miłecki]

On 10.01.2023 13:19, Michael Walle wrote:
> Hi,
>
> Am 2023-01-10 11:54, schrieb Rafał Miłecki:
> > From: Rafał Miłecki <rafal@xxxxxxxxxx>
> >
> > U-Boot environment variables are stored in ASCII format so "ethaddr"
> > requires parsing into binary to make it work with Ethernet interfaces.
> >
> > This includes support for indexes to support #nvmem-cell-cells = <1>.
> >
> > Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
> > ---
> >  drivers/nvmem/layouts/Kconfig      |  1 +
> >  drivers/nvmem/layouts/u-boot-env.c | 24 ++++++++++++++++++++++++
> >  2 files changed, 25 insertions(+)
> >
> > diff --git a/drivers/nvmem/layouts/Kconfig b/drivers/nvmem/layouts/Kconfig
> > index 8a38c514943a..566b4f25630d 100644
> > --- a/drivers/nvmem/layouts/Kconfig
> > +++ b/drivers/nvmem/layouts/Kconfig
> > @@ -23,6 +23,7 @@ config NVMEM_LAYOUT_ONIE_TLV
> >  config NVMEM_LAYOUT_U_BOOT_ENV
> >      bool "U-Boot environment variables support"
> >      select CRC32
> > +    select GENERIC_NET_UTILS
> >      help
> >        U-Boot stores its setup as environment variables. This driver adds
> >        support for verifying & exporting such data. It also exposes variables
> > diff --git a/drivers/nvmem/layouts/u-boot-env.c
> > b/drivers/nvmem/layouts/u-boot-env.c
> > index 95c314553952..63baeb18bd56 100644
> > --- a/drivers/nvmem/layouts/u-boot-env.c
> > +++ b/drivers/nvmem/layouts/u-boot-env.c
> > @@ -4,6 +4,8 @@
> >   */
> >
> >  #include <linux/crc32.h>
> > +#include <linux/etherdevice.h>
> > +#include <linux/if_ether.h>
> >  #include <linux/mod_devicetable.h>
> >  #include <linux/module.h>
> >  #include <linux/nvmem-consumer.h>
> > @@ -36,6 +38,26 @@ struct u_boot_env_image_broadcom {
> >      uint8_t data[];
> >  } __packed;
> >
> > +static int u_boot_env_read_post_process_ethaddr(void *context, const
> > char *id, int index,
> > +                        unsigned int offset, void *data, size_t *bytes)
> > +{
> > +    u8 mac[ETH_ALEN];
> > +
> > +    if (*bytes != 3 * ETH_ALEN - 1)
> > +        return -EINVAL;
> > +
> > +    if (!mac_pton(data, mac))
> > +        return -EINVAL;
> > +
> > +    if (index)
> > +        eth_addr_add(mac, index);
> > +
> > +    ether_addr_copy(data, mac);
> > +    *bytes = ETH_ALEN;
>
> I don't know how to feel about this. This will only work if the new
> size is smaller than the old one. Can't we have a correct size in
> the first place? I.e. while adding the cells.

I didn't think about such solution. I like that idea. Will do.