From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sat, 14 Dec 2019 05:51:54 +0000 (+0200)
Subject: fixed the physical to virtual translation issues with DJGPP, watcom just
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosdemo;a=commitdiff_plain;h=102f82ec5a8128cb076371aa3d9821e684b94380

fixed the physical to virtual translation issues with DJGPP, watcom just
doesn't work at the moment, and seems like it hasn't worked for a while
and went unnoticed? ... oh well
---

diff --git a/Makefile.dj b/Makefile.dj
index a687012..fe89fcf 100644
--- a/Makefile.dj
+++ b/Makefile.dj
@@ -12,7 +12,7 @@ else
 endif
 
 inc = -Isrc -Isrc/dos -Ilibs -Ilibs/imago/src -Ilibs/anim/src -Ilibs/mikmod/include
-opt = -O3 -ffast-math -fno-strict-aliasing
+#opt = -O3 -ffast-math -fno-strict-aliasing
 dbg = -g
 warn = -pedantic -Wall -Wno-unused-function -Wno-unused-variable
 
diff --git a/src/dos/cdpmi.h b/src/dos/cdpmi.h
index 92bc5b3..71138b6 100644
--- a/src/dos/cdpmi.h
+++ b/src/dos/cdpmi.h
@@ -3,7 +3,17 @@
 
 #ifdef __DJGPP__
 #include <dpmi.h>
-#endif
+#include <sys/nearptr.h>
+
+#define virt_to_phys(v)	((v) + __djgpp_base_address)
+#define phys_to_virt(p)	((p) - __djgpp_base_address)
+
+#else	/* not djgpp (basically watcom) */
+
+#define virt_to_phys(v)	(v)
+#define phys_to_virt(p)	(p)
+
+#endif	/* __DJGPP__ */
 
 #include "inttypes.h"
 #include "util.h"
diff --git a/src/dos/gfx.c b/src/dos/gfx.c
index 8818ab9..bc763d3 100644
--- a/src/dos/gfx.c
+++ b/src/dos/gfx.c
@@ -1,16 +1,10 @@
 #include <stdio.h>
+#include <string.h>
 #include "gfx.h"
 #include "vbe.h"
 #include "vga.h"
 #include "cdpmi.h"
 
-#ifdef __DJGPP__
-#include <sys/nearptr.h>
-#define REALPTR(s, o)	(void*)(((uint32_t)(s) << 4) - __djgpp_base_address + ((uint32_t)(o)))
-#else
-#define REALPTR(s, o)	(void*)(((uint32_t)(s) << 4) + ((uint32_t)(o)))
-#endif
-
 #define SAME_BPP(a, b)  \
     ((a) == (b) || ((a) == 16 && (b) == 15) || ((a) == 15 && (b) == 16) || \
      ((a) == 32 && (b) == 24) || ((a) == 24 && (b) == 32))
diff --git a/src/dos/main.c b/src/dos/main.c
index aed12e9..70ea449 100644
--- a/src/dos/main.c
+++ b/src/dos/main.c
@@ -15,6 +15,7 @@
 #include "cfgopt.h"
 #include "logger.h"
 #include "tinyfps.h"
+#include "cdpmi.h"
 
 #undef NOKEYB
 
@@ -31,6 +32,10 @@ static quat_t rot = {0, 0, 0, 1};
 
 int main(int argc, char **argv)
 {
+#ifdef __DJGPP__
+	__djgpp_nearptr_enable();
+#endif
+
 	fbsize = fb_width * fb_height * fb_bpp / 8;
 
 	init_logger("demo.log");
diff --git a/src/dos/vbe.c b/src/dos/vbe.c
index fd894fe..3ada182 100644
--- a/src/dos/vbe.c
+++ b/src/dos/vbe.c
@@ -16,7 +16,7 @@
 		} else { \
 			paddr = ((uint32_t)pseg << 4) + poffs; \
 		} \
-		(ptr) = (void*)paddr; \
+		(ptr) = (void*)phys_to_virt(paddr); \
 	} while(0)
 
 /* hijack the "VESA" sig field, to pre-cache number of modes */
@@ -40,7 +40,7 @@ int vbe_info(struct vbe_info *info)
 	if(!(seg = dpmi_alloc(sizeof *info / 16, &sel))) {
 		return -1;
 	}
-	lowbuf = (void*)((uint32_t)seg << 4);
+	lowbuf = (void*)phys_to_virt((uint32_t)seg << 4);
 
 	memcpy(lowbuf, "VBE2", 4);
 
@@ -107,7 +107,7 @@ int vbe_mode_info(int mode, struct vbe_mode_info *minf)
 	if(!(seg = dpmi_alloc(sizeof *minf / 16, &sel))) {
 		return -1;
 	}
-	lowbuf = (void*)((uint32_t)seg << 4);
+	lowbuf = (void*)phys_to_virt((uint32_t)seg << 4);
 
 	regs.eax = 0x4f01;
 	regs.ecx = mode;
@@ -238,7 +238,7 @@ int vbe_setmode_crtc(uint16_t mode, struct vbe_crtc_info *crtc)
 	if(!(seg = dpmi_alloc((sizeof *crtc + 15) / 16, &sel))) {
 		return -1;
 	}
-	lowbuf = (void*)((uint32_t)seg << 4);
+	lowbuf = (void*)phys_to_virt((uint32_t)seg << 4);
 
 	memcpy(lowbuf, crtc, sizeof *crtc);
 
@@ -293,7 +293,7 @@ int vbe_save(void *stbuf, int sz, unsigned int flags)
 	if(!(seg = dpmi_alloc((sz + 15) / 16, &sel))) {
 		return -1;
 	}
-	lowbuf = (void*)((uint32_t)seg << 4);
+	lowbuf = (void*)phys_to_virt((uint32_t)seg << 4);
 
 	regs.eax = 0x4f04;
 	regs.edx = 1;	/* save */
@@ -319,7 +319,7 @@ int vbe_restore(void *stbuf, int sz, unsigned int flags)
 	if(!(seg = dpmi_alloc((sz + 15) / 16, &sel))) {
 		return -1;
 	}
-	lowbuf = (void*)((uint32_t)seg << 4);
+	lowbuf = (void*)phys_to_virt((uint32_t)seg << 4);
 
 	memcpy(lowbuf, stbuf, sz);