README: document GPT partition flags

README.rst

@@ -129,6 +129,9 @@ Partition options:
 			For hd images this can be used for the last partition. If set
 			the partition will fill the remaining space of the image.
 :bootable:		Boolean specifying whether to set the bootable flag.
+:hidden:		Boolean specifying whether to set the hidden flag (only with GPT).
+:no-automount:		Boolean specifying whether to set the no-automount flag (only with GPT).
+:read-only:		Boolean specifying whether to set the read-only flag (only with GPT).
 :in-partition-table:	Boolean specifying whether to include this partition in
 			the partition table. Defaults to true.
 :forced-primary:	Force this partition to be a primary partition in the
@@ -427,6 +430,24 @@ Options:
 			bigger. This is necessary if the image will be processed by
 			such tools as libvirt, libguestfs or parted.
 
+GPT partition flags
+~~~~~~~~~~~~~~~~~~~
+
+A GPT partition table will translate the following partition configurations to
+the respective GPT flags and set it in the GPT partiton table:
+
+====================== ==============================
+genimage configuration GPT FLAG
+====================== ==============================
+read-only              GPT_PE_FLAG_READ_ONLY (Bit 60)
+bootable               GPT_PE_FLAG_BOOTABLE (Bit 2)
+hidden                 GPT_PE_FLAG_HIDDEN (Bit 62)
+no-automount           GPT_PE_FLAG_NO_AUTO (Bit 63)
+====================== ==============================
+
+Other GPT Flags are currently not supported.
+
+
 iso
 ***
 Generates an ISO image.