[PATCH 05/19] arm64: define DPS root partition type UUID

Vincent Mailhol <[email protected]> Mon, 15 Jun 2026 18:09:01 +0200
Newsgroups org.kernel.vger.linux-efi,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-block,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel
Message-ID <20260615-discoverable-root_partitions-v1-5-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.

Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for arm64 and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.

[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/

Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Signed-off-by: Vincent Mailhol <[email protected]>
---
 arch/arm64/Kconfig                | 1 +
 arch/arm64/include/asm/dps_root.h | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fe60738e5943..190f8dde63b2 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -26,6 +26,7 @@ config ARM64
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DMA_OPS if XEN
 	select ARCH_HAS_DMA_PREP_COHERENT
+	select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
 	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/arm64/include/asm/dps_root.h b/arch/arm64/include/asm/dps_root.h
new file mode 100644
index 000000000000..7344f9a52343
--- /dev/null
+++ b/arch/arm64/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_ARM64_DPS_ROOT_H
+#define _ASM_ARM64_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "b921b045-1df0-41c3-af44-4c6f280d3fae"
+
+#endif /* _ASM_ARM64_DPS_ROOT_H */

-- 
2.53.0