diff --git a/board/mpc8540ads/init.S b/board/mpc8540ads/init.S
index 242cb9f..544fde9 100644
--- a/board/mpc8540ads/init.S
+++ b/board/mpc8540ads/init.S
@@ -260,8 +260,8 @@
 #define LAWBAR2 ((CFG_LBC_SDRAM_BASE>>12) & 0xfffff)
 #define LAWAR2	(LAWAR_EN | LAWAR_TRGT_IF_LBC | (LAWAR_SIZE & LAWAR_SIZE_256M))
 
-#define LAWBAR3 ((CFG_PCI1_IO_BASE>>12) & 0xfffff)
-#define LAWAR3	(LAWAR_EN | LAWAR_TRGT_IF_PCIX | (LAWAR_SIZE & LAWAR_SIZE_16M))
+#define LAWBAR3 ((CFG_PCI1_IO_PHYS>>12) & 0xfffff)
+#define LAWAR3	(LAWAR_EN | LAWAR_TRGT_IF_PCIX | (LAWAR_SIZE & LAWAR_SIZE_1M))
 
 /*
  * Rapid IO at 0xc000_0000 for 512 M
diff --git a/board/mpc8560ads/init.S b/board/mpc8560ads/init.S
index 242cb9f..544fde9 100644
--- a/board/mpc8560ads/init.S
+++ b/board/mpc8560ads/init.S
@@ -260,8 +260,8 @@
 #define LAWBAR2 ((CFG_LBC_SDRAM_BASE>>12) & 0xfffff)
 #define LAWAR2	(LAWAR_EN | LAWAR_TRGT_IF_LBC | (LAWAR_SIZE & LAWAR_SIZE_256M))
 
-#define LAWBAR3 ((CFG_PCI1_IO_BASE>>12) & 0xfffff)
-#define LAWAR3	(LAWAR_EN | LAWAR_TRGT_IF_PCIX | (LAWAR_SIZE & LAWAR_SIZE_16M))
+#define LAWBAR3 ((CFG_PCI1_IO_PHYS>>12) & 0xfffff)
+#define LAWAR3	(LAWAR_EN | LAWAR_TRGT_IF_PCIX | (LAWAR_SIZE & LAWAR_SIZE_1M))
 
 /*
  * Rapid IO at 0xc000_0000 for 512 M
diff --git a/include/configs/MPC8540ADS.h b/include/configs/MPC8540ADS.h
index 74a84f4..5aeea58 100644
--- a/include/configs/MPC8540ADS.h
+++ b/include/configs/MPC8540ADS.h
@@ -330,13 +330,12 @@
 
 /*
  * General PCI
- * Addresses are mapped 1-1.
+ * Memory space is mapped 1-1, but I/O space must start from 0.
  */
 #define CFG_PCI1_MEM_BASE	0x80000000
 #define CFG_PCI1_MEM_PHYS	CFG_PCI1_MEM_BASE
 #define CFG_PCI1_MEM_SIZE	0x20000000	/* 512M */
-
-#define CFG_PCI1_IO_BASE	0x0
+#define CFG_PCI1_IO_BASE	0x00000000
 #define CFG_PCI1_IO_PHYS	0xe2000000
 #define CFG_PCI1_IO_SIZE	0x100000	/* 1M */
 
diff --git a/include/configs/MPC8541CDS.h b/include/configs/MPC8541CDS.h
index db389cf..fb360d2 100644
--- a/include/configs/MPC8541CDS.h
+++ b/include/configs/MPC8541CDS.h
@@ -334,7 +334,7 @@
 
 /*
  * General PCI
- * Addresses are mapped 1-1.
+ * Memory space is mapped 1-1, but I/O space must start from 0.
  */
 #define CFG_PCI1_MEM_BASE	0x80000000
 #define CFG_PCI1_MEM_PHYS	CFG_PCI1_MEM_BASE
diff --git a/include/configs/MPC8548CDS.h b/include/configs/MPC8548CDS.h
index 687fe84..14936c2 100644
--- a/include/configs/MPC8548CDS.h
+++ b/include/configs/MPC8548CDS.h
@@ -340,7 +340,7 @@
 
 /*
  * General PCI
- * Addresses are mapped 1-1.
+ * Memory space is mapped 1-1, but I/O space must start from 0.
  */
 #define CFG_PCI1_MEM_BASE	0x80000000
 #define CFG_PCI1_MEM_PHYS	CFG_PCI1_MEM_BASE
diff --git a/include/configs/MPC8560ADS.h b/include/configs/MPC8560ADS.h
index 835bf5c..21e6637 100644
--- a/include/configs/MPC8560ADS.h
+++ b/include/configs/MPC8560ADS.h
@@ -320,14 +320,14 @@
 
 /*
  * General PCI
- * Addresses are mapped 1-1.
+ * Memory space is mapped 1-1, but I/O space must start from 0.
  */
 #define CFG_PCI1_MEM_BASE	0x80000000
 #define CFG_PCI1_MEM_PHYS	CFG_PCI1_MEM_BASE
 #define CFG_PCI1_MEM_SIZE	0x20000000	/* 512M */
-#define CFG_PCI1_IO_BASE	0xe2000000
-#define CFG_PCI1_IO_PHYS	CFG_PCI1_IO_BASE
-#define CFG_PCI1_IO_SIZE	0x1000000	/* 16M */
+#define CFG_PCI1_IO_BASE	0x00000000
+#define CFG_PCI1_IO_PHYS	0xe2000000
+#define CFG_PCI1_IO_SIZE	0x100000	/* 1M */
 
 #if defined(CONFIG_PCI)