From 9549e660f95c20707a202e11992865f07c7cc3e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vin=C3=ADcius=20Ferr=C3=A3o?=
 <2031761+viniciusferrao@users.noreply.github.com>
Date: Thu, 20 Aug 2026 16:32:27 -0300
Subject: [PATCH] feat(dhcp): boot RISC-V 64-bit UEFI clients with grub2

RISC-V 64-bit UEFI firmware identifies itself with DHCP option 93
client-system-architecture 27 (0x001b, IANA processor architecture
types). Neither DHCP backend knew the value: Kea handed such clients no
boot file and ISC dhcpd fell through to the /yaboot catch-all.

Add an xcat-riscv64 Kea client class and an ISC subnet branch that send
them boot/grub2/grub2.riscv64, the same shape as the aarch64 entries.
The UEFI HTTP boot id (0x001c) is left alone: it needs a URL boot file
and the HTTPClient vendor class, which is a separate change.
---
 perl-xCAT/xCAT/DHCP/BootPolicy.pm    | 5 +++++
 xCAT-server/lib/xcat/plugins/dhcp.pm | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/perl-xCAT/xCAT/DHCP/BootPolicy.pm b/perl-xCAT/xCAT/DHCP/BootPolicy.pm
index c24992d8c..98f1f0b62 100644
--- a/perl-xCAT/xCAT/DHCP/BootPolicy.pm
+++ b/perl-xCAT/xCAT/DHCP/BootPolicy.pm
@@ -36,6 +36,11 @@ sub kea_client_classes {
             test             => 'option[93].hex == 0x000b',
             'boot-file-name' => 'boot/grub2/grub2.aarch64',
         },
+        {
+            name             => 'xcat-riscv64',
+            test             => 'option[93].hex == 0x001b',
+            'boot-file-name' => 'boot/grub2/grub2.riscv64',
+        },
         {
             name             => 'xcat-ppc64',
             test             => 'option[93].hex == 0x000c',
diff --git a/xCAT-server/lib/xcat/plugins/dhcp.pm b/xCAT-server/lib/xcat/plugins/dhcp.pm
index c6afb2adb..1505f4610 100644
--- a/xCAT-server/lib/xcat/plugins/dhcp.pm
+++ b/xCAT-server/lib/xcat/plugins/dhcp.pm
@@ -4467,6 +4467,9 @@ sub addnet
         push @netent,
           "    } else if option client-architecture = 00:0b { #aaarch64\n ";
         push @netent, "      filename \"boot/grub2/grub2.aarch64\";\n";
+        push @netent,
+          "    } else if option client-architecture = 00:1b { #riscv64 uefi\n ";
+        push @netent, "      filename \"boot/grub2/grub2.riscv64\";\n";
         push @netent,
           "    } else if option client-architecture = 00:0e { #OPAL-v3\n ";
         push @netent, "        option conf-file = \"http://$tftp$portsuffix/tftpboot/pxelinux.cfg/p/" . $net . "_" . $maskbits . "\";\n";