Fixes: #3
Fixed: #8
Signed-off-by: Daniel Thompson <[email protected]>
---
Notes:
This patch tries to capture contributions from a long a varied discussion.
I hope I haven't missed anything major.
Thanks to all the contributors to this topic so far!
source/ebbr.rst | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/source/ebbr.rst b/source/ebbr.rst
index 40f03f173bd9..30a9c6ac2666 100644
--- a/source/ebbr.rst
+++ b/source/ebbr.rst
@@ -185,6 +185,53 @@ System Volume Format
--------------------
The system firmware must support GPT partitioning.
+It may optionally also support MBR partitioning.
+
+On systems where the system firmware binaries reside on the System Volume then
+the System Volume must be pre-configured with a partition table and include
+protective partitions to reduce risk of accidental destruction of the system
+firmware.
+
+All pre-configured partition tables must use GPT partitioning unless
+some immutable feature of the platform (such as a mask programmed boot ROM)
+makes this impossible; on such platforms MBR partitioning may be
+used as an alternative.
+
+GPT partitioning
+^^^^^^^^^^^^^^^^
+
+Protective partitions should have the Platform Required Attribute Flag set
+unless some immutable feature of the platform makes this impossible.
+
+It is recommended that automatic system disk partitioning utilities
+preserve Platform Required partitions as is, and that manual disk
+partitioning utilities provide warnings and/or other safe guards to
+reduce risk of accidental removal.
+
+It is recommended that an implementer on a platform where Platform Required
+cannot be set contribute a list of Partition type GUIDs for protective
+partitions to the table below. It is further recommended that disk partitioning
+utilities treat such partitions in the same manner as those with the Platform
+Required Attribute Flag set.
+
++--------------------------------------+---------------------------------------+
+| Partition type GUID | Comment
|
++======================================+=======================================+
+| 00000000-0000-0000-0000-000000000000 | Unused entry (example; do not honour)
|
++--------------------------------------+---------------------------------------+
+
+MBR partitioning
+^^^^^^^^^^^^^^^^
+
+Protective partitions should have a partition type of 0xF8 unless some
+immutable feature of the platform makes this impossible.
+
+It is recommended that disk partitioning utilities treat such
+partitions in the same manner as GPT partitions with the Platform
+Required Attribute Flag set.
+
+It is strongly recommended that protective partitions with a type other
+than 0xF8 be placed within 1MB of the start of the disk.
UEFI Boot Services
==================
--
2.17.0
_______________________________________________
boot-architecture mailing list
[email protected]
https://lists.linaro.org/mailman/listinfo/boot-architecture
