[PATCH v2 3/3] net: consolidate PXE processor architecture type Kconfig

[Ilias Apalodimas]

Hi Heinrich

On Sun, 8 Jun 2025 at 10:42, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> DHCP and DHCPv6 use the same value defined in
> https://www.iana.org/assignments/dhcpv6-parameters#processor-architecture
> to encode the processor architecture type. We should only use a single
> Kconfig symbol for both protocols.
>
> Furthermore we should make the value customizable. This allows for instance
> to choose between "x86 BIOS" or "x64 UEFI".
>
> As "x86 BIOS" is encoded as 0, we should not use this value to switch
> off transmission of the DHCP option. Use 0xFF instead.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  cmd/Kconfig  | 28 ++++++++++++++++------------
>  net/bootp.c  |  6 +++---
>  net/dhcpv6.c |  6 +++---
>  3 files changed, 22 insertions(+), 18 deletions(-)
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index c335eceea63..4eb0140c10a 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -1864,12 +1864,6 @@ config CMD_DHCP6
>
>  if CMD_DHCP6
>
> -config DHCP6_PXE_CLIENTARCH
> -       hex
> -       default 0x16 if ARM64
> -       default 0x15 if ARM
> -       default 0xFF
> -
>  config DHCP6_PXE_DHCP_OPTION
>         bool "Request & store 'pxe_configfile' from DHCP6 server"
>
> @@ -1977,12 +1971,22 @@ config BOOTP_PXE
>         help
>           Supported for ARM, ARM64, and x86 for now.
>
> -config BOOTP_PXE_CLIENTARCH
> -       hex
> -       depends on BOOTP_PXE
> -       default 0x16 if ARM64
> -       default 0x15 if ARM
> -       default 0x0 if X86
> +config DHCP_PXE_CLIENTARCH
> +       hex "DCHCP client system architecture type"

DHCP ?

Other than that
Acked-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>

> +       depends on BOOTP_PXE || CMD_DHCP6
> +       default 0x16 if ARM64 # arm 64 uboot
> +       default 0x15 if ARM   # arm 32 uboot
> +       default 0x0 if X86    # x86 BIOS
> +       default 0xFF          # DHCP option not sent
> +       help
> +         DHCP option 93 (defined in RFC4578) or DHCPv6 option 61 (defined in
> +         RFC 5970) is used to transmit the client system architecture type
> +         to the DHCP server. The DHCP server may use this information to
> +         choose the boot file. For a complete list of assigned values see
> +         https://www.iana.org/assignments/dhcpv6-parameters#processor-architecture.
> +
> +         If the value is set to the reserved value 0xFF, the DHCP option will
> +         not be sent by U-Boot.
>
>  config BOOTP_PXE_DHCP_OPTION
>         bool "Request & store 'pxe_configfile' from BOOTP/DHCP server"
> diff --git a/net/bootp.c b/net/bootp.c
> index f22921ed388..95d906e3b2d 100644
> --- a/net/bootp.c
> +++ b/net/bootp.c
> @@ -545,14 +545,14 @@ static int dhcp_extended(u8 *e, int message_type, struct in_addr server_ip,
>         }
>  #endif
>
> -#ifdef CONFIG_BOOTP_PXE_CLIENTARCH
> -       clientarch = CONFIG_BOOTP_PXE_CLIENTARCH;
> +#ifdef CONFIG_DHCP_PXE_CLIENTARCH
> +       clientarch = CONFIG_DHCP_PXE_CLIENTARCH;
>  #endif
>
>         if (env_get("bootp_arch"))
>                 clientarch = env_get_ulong("bootp_arch", 16, clientarch);
>
> -       if (clientarch > 0) {
> +       if (clientarch != 0xff) {
>                 *e++ = 93;      /* Client System Architecture */
>                 *e++ = 2;
>                 *e++ = (clientarch >> 8) & 0xff;
> diff --git a/net/dhcpv6.c b/net/dhcpv6.c
> index 0c2de75ba1d..5bf935cb6a3 100644
> --- a/net/dhcpv6.c
> +++ b/net/dhcpv6.c
> @@ -128,7 +128,7 @@ static int dhcp6_add_option(int option_id, uchar *pkt)
>                 break;
>         case DHCP6_OPTION_CLIENT_ARCH_TYPE:
>                 client_arch_opt = (struct dhcp6_option_client_arch *)dhcp_option_start;
> -               client_arch_opt->arch_type[num_client_arch++] = htons(CONFIG_DHCP6_PXE_CLIENTARCH);
> +               client_arch_opt->arch_type[num_client_arch++] = htons(CONFIG_DHCP_PXE_CLIENTARCH);
>
>                 opt_len = sizeof(__be16) * num_client_arch;
>                 break;
> @@ -194,7 +194,7 @@ static void dhcp6_send_solicit_packet(void)
>         pkt += dhcp6_add_option(DHCP6_OPTION_ELAPSED_TIME, pkt);
>         pkt += dhcp6_add_option(DHCP6_OPTION_IA_NA, pkt);
>         pkt += dhcp6_add_option(DHCP6_OPTION_ORO, pkt);
> -       if (CONFIG_DHCP6_PXE_CLIENTARCH != 0xFF)
> +       if (CONFIG_DHCP_PXE_CLIENTARCH != 0xFF)
>                 pkt += dhcp6_add_option(DHCP6_OPTION_CLIENT_ARCH_TYPE, pkt);
>         pkt += dhcp6_add_option(DHCP6_OPTION_VENDOR_CLASS, pkt);
>         pkt += dhcp6_add_option(DHCP6_OPTION_NII, pkt);
> @@ -244,7 +244,7 @@ static void dhcp6_send_request_packet(void)
>                 memcpy(pkt, sm_params.server_uid.uid_ptr, sm_params.server_uid.uid_size);
>                 pkt += sm_params.server_uid.uid_size;
>         }
> -       if (CONFIG_DHCP6_PXE_CLIENTARCH != 0xFF)
> +       if (CONFIG_DHCP_PXE_CLIENTARCH != 0xFF)
>                 pkt += dhcp6_add_option(DHCP6_OPTION_CLIENT_ARCH_TYPE, pkt);
>         pkt += dhcp6_add_option(DHCP6_OPTION_VENDOR_CLASS, pkt);
>         pkt += dhcp6_add_option(DHCP6_OPTION_NII, pkt);
> --
> 2.48.1
>