diff --git a/src/common/libsys/boards/sim/board.h b/src/common/libsys/boards/sim/board.h
index 674a752..051be46 100644
--- a/src/common/libsys/boards/sim/board.h
+++ b/src/common/libsys/boards/sim/board.h
@@ -124,6 +124,56 @@
 #define	SYS_SPI_DATA					(SYS_IO_BASE + 0x2000C)
 #define	SYS_SPI_CTRL					(SYS_IO_BASE + 0x20010)
 
+// Ethernet MAC
+#define	SYS_EMAC_RX_CTRL				(SYS_IO_BASE + 0x50000)
+#define	EMAC_RX_CTRL_RESET				(1 << 31)
+#define	EMAC_RX_CTRL_GIGABIT			(1 << 30)
+#define	EMAC_RX_CTRL_FCS_CHECK			(1 << 29)
+#define	EMAC_RX_CTRL_PROMISCIOUS		(1 << 23)
+#define	EMAC_RX_CTRL_PKT_REQ			(1 << 17)
+#define	EMAC_RX_CTRL_PKT_FREE			(1 << 16)
+#define	EMAC_RX_CTRL_INTEN				(1 << 4)
+
+#define	SYS_EMAC_RX_STAT				SYS_EMAC_RX_CTRL
+#define	EMAC_RX_STAT_RESET				(1 << 31)
+#define	EMAC_RX_STAT_GIGABIT			(1 << 30)
+#define	EMAC_RX_STAT_FCS_CHECK			(1 << 29)
+#define	EMAC_RX_STAT_PROMISCIOUS		(1 << 23)
+#define	EMAC_RX_STAT_PKT_BCAST			(1 << 19)
+#define	EMAC_RX_STAT_PKT_MACOK			(1 << 18)
+#define	EMAC_RX_STAT_PKT_VALID			(1 << 17)
+#define	EMAC_RX_STAT_PKT_AVAIL			(1 << 16)
+#define	EMAC_RX_STAT_INTEN				(1 << 4)
+
+#define	SYS_EMAC_RX_SIZE				(SYS_IO_BASE + 0x50004)
+
+#define	SYS_EMAC_TX_CTRL				(SYS_IO_BASE + 0x50008)
+#define	EMAC_TX_CTRL_RESET				(1 << 31)
+#define	EMAC_TX_CTRL_GIGABIT			(1 << 30)
+#define	EMAC_TX_CTRL_FCS_APPEND			(1 << 29)
+#define	EMAC_TX_CTRL_PKT_ALLOC			(1 << 17)
+#define	EMAC_TX_CTRL_PKT_COMMIT			(1 << 16)
+#define	EMAC_TX_CTRL_INTEN				(1 << 4)
+
+#define	SYS_EMAC_TX_STAT				SYS_EMAC_TX_CTRL
+#define	EMAC_TX_STAT_RESET				(1 << 31)
+#define	EMAC_TX_STAT_GIGABIT			(1 << 30)
+#define	EMAC_TX_STAT_FCS_APPEND			(1 << 29)
+#define	EMAC_TX_STAT_PKT_DONE			(1 << 24)
+#define	EMAC_TX_STAT_PKT_ALLOC_BSY		(1 << 17)
+#define	EMAC_TX_STAT_PKT_ARMED			(1 << 16)
+#define	EMAC_TX_STAT_INTEN				(1 << 4)
+
+#define	SYS_EMAC_TX_SIZE				(SYS_IO_BASE + 0x5000C)
+#define	SYS_EMAC_MADDR					(SYS_IO_BASE + 0x50018)
+#define	SYS_EMAC_MADDR_0				SYS_EMAC_MADDR_0
+#define	SYS_EMAC_MADDR_1				(SYS_IO_BASE + 0x5001C)
+
+#define	SYS_EMAC_DATA					(SYS_IO_BASE + 0x58000)
+#define	SYS_EMAC_RX_DATA				SYS_EMAC_DATA
+#define	SYS_EMAC_TX_DATA				SYS_EMAC_DATA
+#define	SYS_EMAC_DATA_CACHED			(0x10008000)
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/test_emac_sim.c b/src/test_emac_sim.c
index 96447fd..2d56167 100644
--- a/src/test_emac_sim.c
+++ b/src/test_emac_sim.c
@@ -5,6 +5,8 @@
 #include <time.h>
 #include <sys/time.h>
 #include <sys/types.h>
+
+#include <board.h>
 #include <libsys/irq.h>
 #include <libsys/cop0.h>