code is a mess currently. I check it in nevertheless since it works a little better than before. Will be cleaned up later.

BaS_gcc/Makefile

@@ -144,6 +144,7 @@ $(LIBBAS): $(OBJS)
 
 # compile xhdi_interface -mshort to make it callable from (-mshort-compiled) EmuTOS
 $(OBJDIR)/xhdi_interface.o: CFLAGS += -mshort
+
 # compile printf pc-relative so it can be used as well before and after copy of BaS
 $(OBJDIR)/bas_printf.o:	CFLAGS += -mpcrel
 # the same for flush_and_invalidate_cache()

BaS_gcc/include/xhdi_sd.h

@@ -86,13 +86,23 @@ typedef void* (*xhdi_call_fun)(int xhdi_fun, ...);
 
 struct XHDICALL_args
 {
-	uint16_t opcode;
+	unsigned int opcode;
 };
 
 extern unsigned long xhdi_call(struct XHDICALL_args stack);
 
 extern xhdi_call_fun xhdi_sd_install(xhdi_call_fun old_vector) __attribute__((__interrupt__));
 
+/*
+ * begin of XHDI calls. The following is a little tricky: since those functions can be called by code compiled with -mshort as
+ * well as from "normal" code, "-mshort"-code needs to be tricked to pass 16-bit values as 32-bit integers.
+ */
+#if __INT_MAX__ == 32767
+#define uint16_t unsigned long
+#define uint32_t unsigned long
+#warning -mshort trick activated
+#endif /* _MSHORT_ */
+
 extern uint16_t xhdi_version(void);	/* XHDI 0 */
 
 extern uint32_t xhdi_inquire_target(uint16_t major, uint16_t minor, uint32_t *block_size, uint32_t *flags,
@@ -139,4 +149,9 @@ extern uint32_t xhdi_last_access(uint16_t major, uint16_t minor, uint32_t *ms);
 
 extern uint32_t xhdi_reaccess(uint16_t major, uint16_t minor);	/* XHDI 19 */
 
+/* disarm stack trick */
+#ifdef uint16_t
+#undef uint16_t
+#undef uint32_t
+#endif /* uint16_t */
 #endif /* _XHDI_SD_H_ */

BaS_gcc/sources/xhdi_interface.c

@@ -29,9 +29,7 @@
 
 unsigned long xhdi_call(struct XHDICALL_args stack)
 {
-	uint16_t opcode = stack.opcode;
+	unsigned int opcode = stack.opcode;
-
-	xprintf("xhdi_call(): opcode %d\r\n", opcode);
 
 	switch (opcode)
 	{
@@ -43,12 +41,12 @@ unsigned long xhdi_call(struct XHDICALL_args stack)
 	{
 		struct XHINQTARGET_args
 		{
-			uint16_t opcode;
-			uint16_t major;
-			uint16_t minor;
-			uint32_t *blocksize;
-			uint32_t *deviceflags;
 			char *productname;
+			unsigned long *deviceflags;
+			unsigned long *blocksize;
+			unsigned int minor;
+			unsigned int major;
+			unsigned int opcode;
 		}*args = (struct XHINQTARGET_args *) &stack;
 
 		return xhdi_inquire_target(args->major, args->minor, args->blocksize,
@@ -60,12 +58,12 @@ unsigned long xhdi_call(struct XHDICALL_args stack)
 	{
 		struct XHRESERVE_args
 		{
-			uint16_t opcode;
-			uint16_t major;
-			uint16_t minor;
-			uint16_t do_reserve;
 			uint16_t key;
-		}*args = (struct XHRESERVE_args *) &stack;
+			uint16_t do_reserve;
+			uint16_t minor;
+			uint16_t major;
+			uint16_t opcode;
+		} *args = (struct XHRESERVE_args *) &stack;
 
 		return xhdi_reserve(args->major, args->minor, args->do_reserve, args->key);
 	}
@@ -121,13 +119,13 @@ unsigned long xhdi_call(struct XHDICALL_args stack)
 	{
 		struct XHINQDEV_args
 		{
-			uint16_t opcode;
-			uint16_t drv;
-			uint16_t *major;
-			uint16_t *minor;
-			uint32_t *start;
 			BPB *bpb;
-		}*args = (struct XHINQDEV_args *) &stack;
+			unsigned long *start;
+			unsigned int *minor;
+			unsigned int *major;
+			unsigned int drv;
+			unsigned int opcode;
+		} *args = (struct XHINQDEV_args *) &stack;
 
 		return xhdi_inquire_device(args->drv, args->major, args->minor, args->start,
 				args->bpb);
@@ -137,13 +135,13 @@ unsigned long xhdi_call(struct XHDICALL_args stack)
 	{
 		struct XHINQDRIVER_args
 		{
-			uint16_t opcode;
-			uint16_t dev;
-			char *name;
-			char *version;
-			char *company;
-			uint16_t *ahdi_version;
 			uint16_t *maxIPL;
+			uint16_t *ahdi_version;
+			char *company;
+			char *version;
+			char *name;
+			uint16_t dev;
+			uint16_t opcode;
 		}*args = (struct XHINQDRIVER_args *) &stack;
 
 		return xhdi_inquire_driver(args->dev, args->name, args->version, args->company,
@@ -154,8 +152,8 @@ unsigned long xhdi_call(struct XHDICALL_args stack)
 	{
 		struct XHNEWCOOKIE_args
 		{
+			unsigned long newcookie;
 			uint16_t opcode;
-			uint32_t newcookie;
 		}*args = (struct XHNEWCOOKIE_args *) &stack;
 
 		return xhdi_new_cookie(args->newcookie);
@@ -165,17 +163,18 @@ unsigned long xhdi_call(struct XHDICALL_args stack)
 	{
 		struct XHREADWRITE_args
 		{
-			uint16_t opcode;
-			uint16_t major;
-			uint16_t minor;
-			uint16_t rw;
-			uint32_t sector;
-			uint16_t count;
 			void *buf;
-		}*args = (struct XHREADWRITE_args *) &stack;
+			unsigned int count;
+			unsigned long sector;
+			unsigned int rw;
+			unsigned int minor;
+			unsigned int major;
+			unsigned int opcode;
+		} *args = (struct XHREADWRITE_args *) &stack;
 
-		return xhdi_read_write(args->major, args->minor, args->rw, args->sector,
+		return xhdi_read_write((unsigned long) args->major, (unsigned long) args->minor,
-				args->count, args->buf);
+								(unsigned long) args->rw, args->sector,
+								(unsigned long) args->count, (unsigned long) args->buf);
 	}
 
 	case XHDI_INQUIRE_TARGET2:

BaS_gcc/sources/xhdi_sd.c

@@ -25,6 +25,7 @@
 
 #include "xhdi_sd.h"
 #include "bas_printf.h"
+#include "bas_string.h"
 
 #define DRIVER_VERSION	0x130
 
@@ -36,6 +37,7 @@ static xhdi_call_fun old_vector = NULL;
 __attribute__((__interrupt__)) xhdi_call_fun xhdi_sd_install(xhdi_call_fun ov)
 {
 	old_vector = ov;
+	uint32_t *_drvbits = (uint32_t *) 0x4c2;
 
 	__asm__ __volatile__ (
 			"move.l		%[xhdi_call],d1\n\t"
@@ -44,6 +46,7 @@ __attribute__((__interrupt__)) xhdi_call_fun xhdi_sd_install(xhdi_call_fun ov)
 			: [xhdi_call]"g"(xhdi_call)
 			: "d1","memory");
 
+	*_drvbits |= (uint32_t) 1 << ('S' - 'A');
 	/*
 	 * this is just to make the compiler happy, the return value is overwritten anyway. Therefore we previously overwrite
 	 * the saved register value on the stack so everything is as we want it to be
@@ -112,8 +115,20 @@ uint32_t xhdi_inquire_device(uint16_t bios_device, uint16_t *major, uint16_t *mi
 uint32_t xhdi_inquire_driver(uint16_t bios_device, char *name, char *version,
 		char *company, uint16_t *ahdi_version, uint16_t *maxIPL)
 {
-	xprintf("xhdi_inquire_driver() called\r\n");
+	xprintf("xhdi_inquire_driver() called. bios_device = %x, name = %p, version = %p,\r\n"
-	return ERROR;
+			"company = %p, ahdi_version = %p, max_IPL = %p\r\n",
+			bios_device, name, version, company, ahdi_version, maxIPL);
+	if (bios_device == 'S' - 'A')
+	{
+		if (name != NULL) strcpy(name, "BaS SD-card driver");
+		if (version != NULL) strcpy(version, "0.1");
+		if (company != NULL) strcpy(company, "Markus Fröschle");
+		if (ahdi_version != NULL) *ahdi_version = 300;
+		if (maxIPL != NULL) *maxIPL = 7;
+
+		return E_OK;
+	}
+	return EUNDEV;
 }
 
 uint32_t xhdi_new_cookie(uint32_t newcookie)
@@ -125,8 +140,9 @@ uint32_t xhdi_new_cookie(uint32_t newcookie)
 uint32_t xhdi_read_write(uint16_t major, uint16_t minor, uint16_t rwflag,
         uint32_t recno, uint16_t count, void *buf)
 {
-	xprintf("xhdi_read_write() called\r\n");
+	xprintf("xhdi_read_write() called: major = %x, minor = %x, rwflag = %x, \r\nrecno = %lx, count = %lx, buf = %p\r\n",
-	return ERROR;
+			major, minor, rwflag, recno, count, buf);
+	return EUNDEV;
 }
 
 uint32_t xhdi_inquire_target2(uint16_t major, uint16_t minor, uint32_t *block_size,
@@ -140,7 +156,12 @@ uint32_t xhdi_inquire_device2(uint16_t bios_device, uint16_t *major, uint16_t *m
         uint32_t *start_sector, BPB *bpb, uint32_t *blocks, char *partid)
 {
 	xprintf("xhdi_inquire_device2() called\r\n");
-	return ERROR;
+
+	if (bios_device == 'S' - 'A')
+	{
+		return E_OK;
+	}
+	return EUNDEV;
 }
 
 uint32_t xhdi_driver_special(uint32_t key1, uint32_t key2, uint16_t subopcode, void *data)