From 92bc7be93ea01896b93f2986c6029b5932c32d97 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Thu, 5 Dec 2019 04:03:13 +0200
Subject: [PATCH] added missing "modify" declarations in cdpmi.h inline
 assembly blocks

---
 src/dos/cdpmi.h |    7 ++++---
 src/dos/gfx.c   |   20 +++++++++++++++++++-
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/dos/cdpmi.h b/src/dos/cdpmi.h
index 4fc2c30..92bc5b3 100644
--- a/src/dos/cdpmi.h
+++ b/src/dos/cdpmi.h
@@ -34,7 +34,8 @@ void dpmi_munmap(void *addr);
 		"xor ax, ax" \
 		"alloc_skip_err:" \
 		value[ax] \
-		parm[ebx][edi];
+		parm[ebx][edi] \
+		modify[dx];
 
 #pragma aux dpmi_free = \
 		"mov ax, 0x101" \
@@ -65,7 +66,7 @@ void dpmi_munmap(void *addr);
 		"mov ax, cx" \
 		value[eax] \
 		parm[ebx][esi] \
-		modify[cx di];
+		modify[bx cx di esi];
 
 #pragma aux dpmi_munmap = \
 		"mov ax, 0x801" \
@@ -73,7 +74,7 @@ void dpmi_munmap(void *addr);
 		"shr ebx, 16" \
 		"int 0x31" \
 		parm[ebx] \
-		modify[ax];
+		modify[ax cx ebx];
 #endif	/* __WATCOMC__ */
 
 #ifdef __DJGPP__
diff --git a/src/dos/gfx.c b/src/dos/gfx.c
index b5670bf..d0128ee 100644
--- a/src/dos/gfx.c
+++ b/src/dos/gfx.c
@@ -25,11 +25,25 @@ static int fbidx;
 
 static int init_vbe(void)
 {
+	int i, num;
+
 	if(vbe_info(&vbe) == -1) {
+		fprintf(stderr, "failed to retrieve VBE information\n");
 		return -1;
 	}
 
 	vbe_print_info(stdout, &vbe);
+
+	num = vbe_num_modes(&vbe);
+	for(i=0; i<num; i++) {
+		struct vbe_mode_info minf;
+
+		if(vbe_mode_info(vbe.modes[i], &minf) == -1) {
+			continue;
+		}
+		printf("%04x: ", vbe.modes[i]);
+		vbe_print_mode_info(stdout, &minf);
+	}
 	fflush(stdout);
 
 	vbe_init_ver = VBE_VER_MAJOR(vbe.ver);
@@ -56,7 +70,11 @@ void *set_video_mode(int xsz, int ysz, int bpp)
 	mode = -1;
 	nmodes = vbe_num_modes(&vbe);
 	for(i=0; i<nmodes; i++) {
-		vbe_mode_info(vbe.modes[i], &minf);
+		if(vbe_mode_info(vbe.modes[i], &minf) == -1) {
+			continue;
+		}
+		printf("trying to match mode: %d (%dx%d %dbpp)\n", vbe.modes[i],
+				minf.xres, minf.yres, minf.bpp);
 		if(minf.xres != xsz || minf.yres != ysz) continue;
 		if(minf.bpp == bpp) {
 			mode = vbe.modes[i];
-- 
1.7.10.4