diff --git a/include/asm-m68k/mac_baboon.h b/include/asm-m68k/mac_baboon.h
new file mode 100644
index 0000000..e878508
--- /dev/null
+++ b/include/asm-m68k/mac_baboon.h
@@ -0,0 +1,34 @@
+/*
+ * Definitions for the "Baboon" custom IC on the PowerBook 190.
+ */
+
+#define BABOON_BASE (0x50F1A000)	/* same as IDE controller base */
+
+#ifndef __ASSEMBLY__
+
+struct baboon {
+	char	pad1[208];	/* generic IDE registers, not used here */
+	short	mb_control;	/* Control register:
+				 * bit 5 : slot 2 power control
+				 * bit 6 : slot 1 power control
+				 */
+	char	pad2[2];
+	short	mb_status;	/* (0xD4) media bay status register:
+				 *
+				 * bit 0: ????
+				 * bit 1: IDE interrupt active?
+				 * bit 2: bay status, 0 = full, 1 = empty
+				 * bit 3: ????
+				 */
+	char	pad3[2];	/* (0xD6) not used */
+	short	mb_ifr;		/* (0xD8) media bay interrupt flags register:
+				 *
+				 * bit 0: ????
+				 * bit 1: IDE controller interrupt
+				 * bit 2: media bay status change interrupt
+				 */
+};
+
+extern volatile struct baboon *baboon;
+
+#endif /* __ASSEMBLY **/