diff --git a/board/esd/pci405/writeibm.S b/board/esd/pci405/writeibm.S
new file mode 100644
index 0000000000..b08c9ac893
--- /dev/null
+++ b/board/esd/pci405/writeibm.S
@@ -0,0 +1,235 @@
+/*------------------------------------------------------------------------------+ */
+/* */
+/*       This source code has been made available to you by IBM on an AS-IS */
+/*       basis.  Anyone receiving this source is licensed under IBM */
+/*       copyrights to use it in any way he or she deems fit, including */
+/*       copying it, modifying it, compiling it, and redistributing it either */
+/*       with or without modifications.  No license under IBM patents or */
+/*       patent applications is to be implied by the copyright license. */
+/* */
+/*       Any user of this software should understand that IBM cannot provide */
+/*       technical support for this software and will not be responsible for */
+/*       any consequences resulting from the use of this software. */
+/* */
+/*       Any person who transfers this source code or any derivative work */
+/*       must include the IBM copyright notice, this paragraph, and the */
+/*       preceding two paragraphs in the transferred software. */
+/* */
+/*       COPYRIGHT   I B M   CORPORATION 1995 */
+/*       LICENSED MATERIAL  -  PROGRAM PROPERTY OF I B M */
+/*------------------------------------------------------------------------------- */
+
+/*----------------------------------------------------------------------------- */
+/* Function:     ext_bus_cntlr_init */
+/* Description:  Initializes the External Bus Controller for the external */
+/*		peripherals. IMPORTANT: For pass1 this code must run from */
+/*		cache since you can not reliably change a peripheral banks */
+/*		timing register (pbxap) while running code from that bank. */
+/*		For ex., since we are running from ROM on bank 0, we can NOT */
+/*		execute the code that modifies bank 0 timings from ROM, so */
+/*		we run it from cache. */
+/*	Bank 0 - Flash and SRAM */
+/*	Bank 1 - NVRAM/RTC */
+/*	Bank 2 - Keyboard/Mouse controller */
+/*	Bank 3 - IR controller */
+/*	Bank 4 - not used */
+/*	Bank 5 - not used */
+/*	Bank 6 - not used */
+/*	Bank 7 - FPGA registers */
+/*----------------------------------------------------------------------------- */
+#include <ppc4xx.h>
+
+#include <ppc_asm.tmpl>
+#include <ppc_defs.h>
+
+#include <asm/cache.h>
+#include <asm/mmu.h>
+
+
+	.globl	write_without_sync
+write_without_sync:
+		/*
+		 * Write one values to host via pci busmastering
+                 * ptr = 0xc0000000 -> 0x01000000 (PCI)
+                 * *ptr = 0x01234567;
+		 */
+        addi    r31,0,0
+        lis     r31,0xc000
+
+start1:
+        lis     r0,0x0123
+        ori     r0,r0,0x4567
+        stw     r0,0(r31)
+
+		/*
+		 * Read one value back
+                 * ptr = (volatile unsigned long *)addr;
+                 * val = *ptr;
+		 */
+
+        lwz     r0,0(r31)
+
+		/*
+		 * One pci config write
+                 * ibmPciConfigWrite(0x2e, 2, 0x1234);
+		 */
+		/* subsystem id */
+
+
+
+        li      r4,0x002C
+        oris    r4,r4,0x8000
+        lis     r3,0xEEC0
+        stwbrx  r4,0,r3
+
+        li      r5,0x1234
+        ori     r3,r3,0x4
+        stwbrx  r5,0,r3
+
+        b       start1
+
+	blr	/* never reached !!!! */
+
+
+
+	.globl	write_with_sync
+write_with_sync:
+		/*
+		 * Write one values to host via pci busmastering
+                 * ptr = 0xc0000000 -> 0x01000000 (PCI)
+                 * *ptr = 0x01234567;
+		 */
+        addi    r31,0,0
+        lis     r31,0xc000
+
+start2:
+        lis     r0,0x0123
+        ori     r0,r0,0x4567
+        stw     r0,0(r31)
+
+		/*
+		 * Read one value back
+                 * ptr = (volatile unsigned long *)addr;
+                 * val = *ptr;
+		 */
+
+        lwz     r0,0(r31)
+
+		/*
+		 * One pci config write
+                 * ibmPciConfigWrite(0x2e, 2, 0x1234);
+		 */
+		/* subsystem id */
+
+
+
+        li      r4,0x002C
+        oris    r4,r4,0x8000
+        lis     r3,0xEEC0
+        stwbrx  r4,0,r3
+        sync
+
+        li      r5,0x1234
+        ori     r3,r3,0x4
+        stwbrx  r5,0,r3
+        sync
+
+        b       start2
+
+	blr	/* never reached !!!! */
+
+
+	.globl	write_with_less_sync
+write_with_less_sync:
+		/*
+		 * Write one values to host via pci busmastering
+                 * ptr = 0xc0000000 -> 0x01000000 (PCI)
+                 * *ptr = 0x01234567;
+		 */
+        addi    r31,0,0
+        lis     r31,0xc000
+
+start2b:
+        lis     r0,0x0123
+        ori     r0,r0,0x4567
+        stw     r0,0(r31)
+
+		/*
+		 * Read one value back
+                 * ptr = (volatile unsigned long *)addr;
+                 * val = *ptr;
+		 */
+
+        lwz     r0,0(r31)
+
+		/*
+		 * One pci config write
+                 * ibmPciConfigWrite(0x2e, 2, 0x1234);
+		 */
+		/* subsystem id */
+
+
+
+        li      r4,0x002C
+        oris    r4,r4,0x8000
+        lis     r3,0xEEC0
+        stwbrx  r4,0,r3
+        sync
+
+        li      r5,0x1234
+        ori     r3,r3,0x4
+        stwbrx  r5,0,r3
+/*        sync */
+
+        b       start2b
+
+	blr	/* never reached !!!! */
+
+
+	.globl	write_with_more_sync
+write_with_more_sync:
+		/*
+		 * Write one values to host via pci busmastering
+                 * ptr = 0xc0000000 -> 0x01000000 (PCI)
+                 * *ptr = 0x01234567;
+		 */
+        addi    r31,0,0
+        lis     r31,0xc000
+
+start3:
+        lis     r0,0x0123
+        ori     r0,r0,0x4567
+        stw     r0,0(r31)
+        sync
+
+		/*
+		 * Read one value back
+                 * ptr = (volatile unsigned long *)addr;
+                 * val = *ptr;
+		 */
+
+        lwz     r0,0(r31)
+        sync
+
+		/*
+		 * One pci config write
+                 * ibmPciConfigWrite(0x2e, 2, 0x1234);
+		 */
+		/* subsystem id (PCIC0_SBSYSVID)*/
+
+
+
+        li      r4,0x002C
+        oris    r4,r4,0x8000
+        lis     r3,0xEEC0
+        stwbrx  r4,0,r3
+        sync
+
+        li      r5,0x1234
+        ori     r3,r3,0x4
+        stwbrx  r5,0,r3
+        sync
+
+        b       start3
+
+	blr	/* never reached !!!! */