Fix the DOS port

Now the DS selector limit is set to 4GB and all mmio accesses goes
through DS, the 1:1 mapping is fixed so the _DS base is taken onto
account. Plus is that the hwaccess.c needs no change and memcpy etc can
be used on mmaped space.

Corresponding to flashrom svn r995.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz> 
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

Makefile

@@ -202,12 +202,8 @@ endif
 endif
 
 ifeq ($(NEED_PCI), yes)
-ifneq ($(OS_ARCH), DOS)
-# FIXME This workaround is needed until libpci detection can handle
-# cross-compiling for DOS.
 CHECK_LIBPCI = yes
 endif
-endif
 
 ifeq ($(NEED_PCI), yes)
 FEATURE_CFLAGS += -D'NEED_PCI=1'

hwaccess.c

@@ -54,44 +54,6 @@ void release_io_perms(void)
 #endif
 }
 
-#ifdef __DJGPP__
-
-extern unsigned short  segFS;
-
-#include <sys/farptr.h>
-
-void mmio_writeb(uint8_t val, void *addr)
-{
-	_farpokeb(segFS, (unsigned long) addr, val);
-}
-
-void mmio_writew(uint16_t val, void *addr)
-{
-	_farpokew(segFS, (unsigned long) addr, val);
-}
-
-void mmio_writel(uint32_t val, void *addr)
-{
-	_farpokel(segFS, (unsigned long) addr, val);
-}
-
-uint8_t mmio_readb(void *addr)
-{
-	return _farpeekb(segFS, (unsigned long) addr);
-}
-
-uint16_t mmio_readw(void *addr)
-{
-	return _farpeekw(segFS, (unsigned long) addr);
-}
-
-uint32_t mmio_readl(void *addr)
-{
-	return _farpeekl(segFS, (unsigned long) addr);
-}
-
-#else
-
 void mmio_writeb(uint8_t val, void *addr)
 {
 	*(volatile uint8_t *) addr = val;
@@ -121,4 +83,3 @@ uint32_t mmio_readl(void *addr)
 {
 	return *(volatile uint32_t *) addr;
 }
-#endif

physmap.c

@@ -30,66 +30,67 @@
 
 #ifdef __DJGPP__
 #include <dpmi.h>
+#include <sys/nearptr.h>
 
 #define MEM_DEV "dpmi"
 
-unsigned short  segFS = 0;
+static void *realmem_map;
 
-void *sys_physmap(unsigned long phys_addr, size_t len)
+static void *map_first_meg(unsigned long phys_addr, size_t len)
 {
-	int ret;
-	__dpmi_meminfo mi;
 
-	if (segFS == 0)  {
-		segFS = __dpmi_allocate_ldt_descriptors (1);
-		__dpmi_set_segment_base_address (segFS, 0x0);
-		__dpmi_set_segment_limit (segFS, 0xffffffff);
+	if (realmem_map) {
+		return realmem_map + phys_addr;
 	}
 
-	mi.address = phys_addr;
-	mi.size = len;
-	ret =  __dpmi_physical_address_mapping (&mi);
+	realmem_map = valloc(1024 * 1024);
 
-	if (ret != 0) {
+	if (!realmem_map) {
 		return NULL;
 	}
 
-	return (void *) mi.address;
-}
-
-#define sys_physmap_rw_uncached	sys_physmap
-
-#include <sys/movedata.h>
-#include <sys/segments.h>
-#include <go32.h>
+	if (__djgpp_map_physical_memory(realmem_map, (1024 * 1024), 0)) {
+		return NULL;
+	}
 
-static void *realmem_cpy;
+	return realmem_map + phys_addr;
+}
 
-void *sys_physmap_ro_cached(unsigned long phys_addr, size_t len)
+void *sys_physmap(unsigned long phys_addr, size_t len)
 {
-	/* no support for not a 1MB of mem */
-	if ((phys_addr + len) > 1024*1024)
+	int ret;
+	__dpmi_meminfo mi;
+
+	/* enable 4GB limit on DS descriptor */
+	if (!__djgpp_nearptr_enable()) {
 		return NULL;
+	}
 
-	if (realmem_cpy)
-		return realmem_cpy + phys_addr;
+	if ((phys_addr + len - 1) < (1024 * 1024)) {
+	/* we need to use another method to map first 1MB */
+		return map_first_meg(phys_addr, len);
+	}
 
-	realmem_cpy = valloc(1024*1024);
+	mi.address = phys_addr;
+	mi.size = len;
+	ret =  __dpmi_physical_address_mapping (&mi);
 
-	if (!realmem_cpy)
+	if (ret != 0) {
 		return NULL;
+	}
 
-	movedata(_dos_ds, 0, _my_ds(), (unsigned long) realmem_cpy, 1024*1024);
-	return realmem_cpy + phys_addr;
+	return (void *) mi.address + __djgpp_conventional_base;
 }
 
+#define sys_physmap_rw_uncached	sys_physmap
+#define sys_physmap_ro_cached	sys_physmap
 
 void physunmap(void *virt_addr, size_t len)
 {
 	__dpmi_meminfo mi;
 
-	/* we ignore unmaps for our cheat 1MB copy */
-	if ((virt_addr >= realmem_cpy) && ((virt_addr + len) <= (realmem_cpy + 1024*1024))) {
+	/* we ignore unmaps for our first 1MB */
+	if ((virt_addr >= realmem_map) && ((virt_addr + len) <= (realmem_map + (1024 * 1024)))) {
 		return;
 	}