NFC CHERI: move sealing type definitions to C

Extract the source of truth from loader/boot.cc to a new C enum in
cheri.h and redefine the loader's enum in terms of the latter.

sdk/core/loader/boot.cc

diff --git a/sdk/core/loader/boot.cc b/sdk/core/loader/boot.cc
index 01e4ca7..e41038a 100644
--- a/sdk/core/loader/boot.cc
+++ b/sdk/core/loader/boot.cc
@@ -68,12 +68,12 @@
 		/**
 		 * 0 represents unsealed.
 		 */
-		Unsealed = 0,
+		Unsealed = CheriSealTypeUnsealed,
 
 		/**
 		 * Sentry that inherits interrupt status.
 		 */
-		SentryInheriting,
+		SentryInheriting = CheriSealTypeSentryInheriting,
 
 		/// Alternative name: the default sentry type.
 		Sentry = SentryInheriting,
@@ -81,32 +81,32 @@
 		/**
 		 * Sentry that disables interrupts on calls.
 		 */
-		SentryDisabling,
+		SentryDisabling = CheriSealTypeSentryDisabling,
 
 		/**
 		 * Sentry that enables interrupts on calls.
 		 */
-		SentryEnabling,
+		SentryEnabling = CheriSealTypeSentryEnabling,
 
 		/**
 		 * Return sentry that disables interrupts on return
 		 */
-		ReturnSentryDisabling,
+		ReturnSentryDisabling = CheriSealTypeReturnSentryDisabling,
 
 		/**
 		 * Return sentry that enables interrupts on return
 		 */
-		ReturnSentryEnabling,
+		ReturnSentryEnabling = CheriSealTypeReturnSentryEnabling,
 
 		/**
 		 * Marker for the first sealing type that's valid for data capabilities.
 		 */
-		FirstDataSealingType = 9,
+		FirstDataSealingType = CheriSealTypeFirstDataSealingType,
 
 		/**
 		 * The sealing type used for sealed export table entries.
 		 */
-		SealedImportTableEntries = FirstDataSealingType,
+		SealedImportTableEntries = CheriSealTypeSealedImportTableEntries,
 
 		/**
 		 * The compartment switcher has a sealing type for the trusted stack.
@@ -114,13 +114,13 @@
 		 * This must be the second data sealing type so that we can also permit
 		 * the switcher to unseal sentries and export table entries.
 		 */
-		SealedTrustedStacks,
+		SealedTrustedStacks = CheriSealTypeSealedTrustedStacks,
 
 		/**
 		 * The allocator has a sealing type for the software sealing mechanism
 		 * with dynamically allocated objects.
 		 */
-		Allocator,
+		Allocator = CheriSealTypeAllocator,
 
 		/**
 		 * The loader reserves a sealing type for the software sealing
@@ -129,19 +129,19 @@
 		 * type was present in the original firmware image.  The token library
 		 * has the only permit-unseal capability for this type.
 		 */
-		StaticToken,
+		StaticToken = CheriSealTypeStaticToken,
 
 		/**
 		 * The first sealing key that is reserved for use by the allocator's
 		 * software sealing mechanism and used for static sealing types,
 		 */
-		FirstStaticSoftware = 16,
+		FirstStaticSoftware = CheriSealTypeFirstStaticSoftware,
 
 		/**
 		 * The first sealing key in the space that the allocator will
 		 * dynamically allocate for sealing types.
 		 */
-		FirstDynamicSoftware = 0x1000000,
+		FirstDynamicSoftware = CheriSealTypeFirstDynamicSoftware,
 	};
 
 	// The switcher assembly includes the types of import table entries and

sdk/include/cheri.h

diff --git a/sdk/include/cheri.h b/sdk/include/cheri.h
index 59385d1..b10d059 100644
--- a/sdk/include/cheri.h
+++ b/sdk/include/cheri.h
@@ -269,6 +269,99 @@
 };
 
 /**
+ * Sealing types.
+ */
+enum CHERISealingType
+{
+	/**
+	 * 0 represents unsealed.
+	 */
+	CheriSealTypeUnsealed = 0,
+
+	/**
+	 * Sentry that inherits interrupt status.
+	 */
+	CheriSealTypeSentryInheriting,
+
+	/**
+	 * Sentry that disables interrupts on calls.
+	 */
+	CheriSealTypeSentryDisabling,
+
+	/**
+	 * Sentry that enables interrupts on calls.
+	 */
+	CheriSealTypeSentryEnabling,
+
+	/**
+	 * Return sentry that disables interrupts on return
+	 */
+	CheriSealTypeReturnSentryDisabling,
+
+	/**
+	 * Return sentry that enables interrupts on return
+	 */
+	CheriSealTypeReturnSentryEnabling,
+
+	/**
+	 * Marker for the first sealing type that's valid for data capabilities.
+	 */
+	CheriSealTypeFirstDataSealingType = 9,
+
+	/**
+	 * The sealing type used for sealed export table entries.
+	 *
+	 * This is RTOS- and not CHERIoT-specific.
+	 */
+	CheriSealTypeSealedImportTableEntries = CheriSealTypeFirstDataSealingType,
+
+	/**
+	 * The compartment switcher has a sealing type for the trusted stack.
+	 *
+	 * This must be the second data sealing type so that we can also permit
+	 * the switcher to unseal sentries and export table entries.
+	 *
+	 * This is RTOS- and not CHERIoT-specific.
+	 */
+	CheriSealTypeSealedTrustedStacks,
+
+	/**
+	 * The allocator has a sealing type for the software sealing mechanism
+	 * with dynamically allocated objects.
+	 *
+	 * This is RTOS- and not CHERIoT-specific.
+	 */
+	CheriSealTypeAllocator,
+
+	/**
+	 * The loader reserves a sealing type for the software sealing
+	 * mechanism.  The permit-unseal capability for this is destroyed after
+	 * the loader has run, which guarantees that anything sealed with this
+	 * type was present in the original firmware image.  The token library
+	 * has the only permit-unseal capability for this type.
+	 *
+	 * This is RTOS- and not CHERIoT-specific.
+	 */
+	CheriSealTypeStaticToken,
+
+	/**
+	 * The first sealing key that is reserved for use by the allocator's
+	 * software sealing mechanism and used for static sealing types,
+	 *
+	 * Architecturally, this is the smallest non-interpreted sealing type.
+	 */
+	CheriSealTypeFirstStaticSoftware = 16,
+
+	/**
+	 * The first sealing key in the space that the allocator will
+	 * dynamically allocate for sealing types.
+	 *
+	 * This is RTOS- and not CHERIoT-specific.
+	 */
+	CheriSealTypeFirstDynamicSoftware = 0x1000000
+};
+
+/**
  * Checks that `ptr` is valid, unsealed, has at least `rawPermissions`, and has
  * at least `space` bytes after the current offset.
  *