zdump: dfi_elf: factor out some ELF functionalities

This makes them reuseable and testable.

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdump/df_elf.h

@@ -14,6 +14,7 @@
 
 #include <elf.h>
 #include <linux/types.h>
+#include <stdbool.h>
 
 #include "lib/zt_common.h"
 
@@ -127,6 +128,21 @@ static inline void df_elf_ensure_s390x(void)
  */
 void *ehdr_init(Elf64_Ehdr *ehdr, Elf64_Half phnum);
 
+/*
+ * Checks whether @ehdr is a ELF object
+ */
+bool ehdr_is_elf_object(const Elf64_Ehdr *ehdr);
+
+/*
+ * Checks whether @ehdr is a vmcore
+ */
+bool ehdr_is_vmcore(const Elf64_Ehdr *ehdr);
+
+/*
+ * Checks whether @ehdr is a s390x header
+ */
+bool ehdr_is_s390x(const Elf64_Ehdr *ehdr);
+
 /*
  * Initialize ELF note
  */