diff -rup origsrc/rng-tools-5/configure.ac src/rng-tools-5/configure.ac
--- origsrc/rng-tools-5/configure.ac	2014-08-12 10:33:32.064585400 +0200
+++ src/rng-tools-5/configure.ac	2014-08-12 11:18:44.431782000 +0200
@@ -56,6 +56,8 @@ dnl ------------------------------------
 dnl Checks for optional library functions
 dnl -------------------------------------
 
+AC_SEARCH_LIBS([argp_parse],[argp])
+
 dnl -------------------------------------
 dnl Check for libgcrypt support
 dnl -------------------------------------
diff -rup origsrc/rng-tools-5/rdrand_asm.S src/rng-tools-5/rdrand_asm.S
--- origsrc/rng-tools-5/rdrand_asm.S	2014-08-13 10:16:08.499091900 +0200
+++ src/rng-tools-5/rdrand_asm.S	2014-08-13 10:12:40.745403500 +0200
@@ -20,20 +20,43 @@
 
 #if defined(__i386__) || defined(__x86_64__)
 
-#define ENTRY(x)	  \
-	.balign	64	; \
-	.globl	x	; \
-x:
+#if defined __CYGWIN__
+# if defined __x86_64__
+#  define MS_x86_64_ABI
+# else
+#  define SYMBOL(name) _ ## name
+# endif
+#else
+# define ELF_DEBUG_INFO
+#endif
+#if !defined SYMBOL
+# define SYMBOL(name) name
+#endif
+
+#define ENTRY(x)		  \
+	.balign	64		; \
+	.globl	SYMBOL(x)	; \
+SYMBOL(x):
 
+#if defined ELF_DEBUG_INFO
 #define ENDPROC(x)		  \
 	.size	x, .-x		; \
 	.type	x, @function
+#else
+#define ENDPROC(x)
+#endif
 
 #define RDRAND_RETRY_LIMIT	10
 
 #ifdef __x86_64__
 
 ENTRY(x86_rdrand_bytes)
+#if defined MS_x86_64_ABI
+	push	%rdi
+	push	%rsi
+	mov	%rcx, %rdi
+	mov	%rdx, %rsi
+#endif
 	mov	%esi, %eax
 1:
 	mov	$RDRAND_RETRY_LIMIT, %ecx
@@ -46,6 +69,10 @@ ENTRY(x86_rdrand_bytes)
 	ja	1b
 4:
 	sub	%esi, %eax
+#if defined MS_x86_64_ABI
+	pop	%rsi
+	pop	%rdi
+#endif
 	ret
 3:
 	dec	%ecx
@@ -55,6 +82,14 @@ ENTRY(x86_rdrand_bytes)
 ENDPROC(x86_rdrand_bytes)
 
 ENTRY(x86_rdseed_or_rdrand_bytes)
+#if defined MS_x86_64_ABI
+	push	%rdi
+	push	%rsi
+	mov	%rcx, %rdi
+	mov	%rdx, %rsi
+	mov	%r8, %rdx
+	mov	%r9, %rcx
+#endif
 	mov	(%rsi), %r8d		/* RDSEED count */
 	mov	(%rcx), %r9d		/* RDRAND count */
 1:
@@ -69,6 +104,10 @@ ENTRY(x86_rdseed_or_rdrand_bytes)
 4:
 	sub	%r8d, (%rsi)
 	sub	%r9d, (%rcx)
+#if defined MS_x86_64_ABI
+	pop	%rsi
+	pop	%rdi
+#endif
 	ret
 3:
 	.byte	0x48,0x0f,0xc7,0xf0	/* rdrand %rax */
@@ -191,6 +230,12 @@ ENTRY(x86_aes_mangle)
 	movl	12(%ebp), %edx
 	push	%esi
 #endif
+#if defined MS_x86_64_ABI
+	push	%rdi
+	push	%rsi
+	mov	%rcx, %rdi
+	mov	%rdx, %rsi
+#endif
 	movl	$512, CTR3	/* Number of rounds */
 	
 	movdqa	(0*16)(PTR1), %xmm0
@@ -283,6 +328,10 @@ offset = offset + 16
 	pop	%esi
 	pop	%ebp
 #endif
+#if defined MS_x86_64_ABI
+	pop	%rsi
+	pop	%rdi
+#endif
 	ret
 ENDPROC(x86_aes_mangle)
 
@@ -295,6 +344,11 @@ ENTRY(x86_aes_expand_key)
 	mov	%esp, %ebp
 	movl	8(%ebp), %eax
 #endif
+#if defined MS_x86_64_ABI
+	push	%rdi
+	push	%rsi
+	mov	%rcx, %rdi
+#endif
 
 	SETPTR(aes_round_keys, PTR1)
 	movdqu	(PTR0), %xmm0
@@ -325,6 +379,10 @@ ENTRY(x86_aes_expand_key)
 #ifdef __i386__
 	pop	%ebp
 #endif
+#if defined MS_x86_64_ABI
+	pop	%rsi
+	pop	%rdi
+#endif
 	ret
 
 1:
@@ -347,12 +405,16 @@ ENDPROC(x86_aes_expand_key)
 	.balign 64
 aes_round_keys:
 	.space	11*16
+#if defined ELF_DEBUG_INFO
 	.size	aes_round_keys, .-aes_round_keys
+#endif /* ELF_DEBUG_INFO */
 
 #endif /* i386 or x86_64 */
 
+#if defined ELF_DEBUG_INFO
 /*
  * This is necessary to keep the whole executable
  * from needing a writable stack.
  */
                 .section        .note.GNU-stack,"",%progbits
+#endif /* ELF_DEBUG_INFO */
diff -rup origsrc/rng-tools-5/rngd_linux.c src/rng-tools-5/rngd_linux.c
--- origsrc/rng-tools-5/rngd_linux.c	2012-08-06 19:04:12.000000000 +0200
+++ src/rng-tools-5/rngd_linux.c	2014-08-09 15:09:21.081616358 +0200
@@ -39,8 +39,10 @@
 #include <fcntl.h>
 #include <sys/time.h>
 #include <time.h>
+#ifndef __CYGWIN__
 #include <linux/types.h>
 #include <linux/random.h>
+#endif
 #include <string.h>
 
 #include "rngd.h"
@@ -130,11 +132,19 @@ void random_add_entropy(void *buf, size_
 	entropy.size = size;
 	memcpy(entropy.data, buf, size);
 
+#ifdef __CYGWIN__
+	if (write(random_fd, entropy.data, size) != size) {
+		message(LOG_DAEMON|LOG_ERR, "Add Entropy failed: %s\n",
+			strerror(errno));
+		exit(1);
+	}
+#else
 	if (ioctl(random_fd, RNDADDENTROPY, &entropy) != 0) {
 		message(LOG_DAEMON|LOG_ERR, "RNDADDENTROPY failed: %s\n",
 			strerror(errno));
 		exit(1);
 	}
+#endif
 }
 
 void random_sleep(void)