From 898a618bf25182f1e3b456303c3c2613c170856e Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 25 Jun 2023 01:07:03 +0300
Subject: [PATCH] vbe

---
 drv_vbe.c |  110 ++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 vidsys.c  |    2 +-
 vidsys.h  |    4 ++-
 3 files changed, 98 insertions(+), 18 deletions(-)

diff --git a/drv_vbe.c b/drv_vbe.c
index e051692..59ec306 100644
--- a/drv_vbe.c
+++ b/drv_vbe.c
@@ -16,16 +16,19 @@ static int getmode(void);
 static const char *memsize_str(long sz);
 static int get_mode_info(int mode, struct vbe_mode_info *mi);
 static int conv_vbeinfo(int mode, struct vid_modeinfo *mi, struct vbe_mode_info *vbemi);
+static unsigned int calc_mask(int nbits, int pos);
 
-static struct vid_driver drv = {"vbe", 2};
+static struct vid_driver drv;
 static struct vid_drvops drvops = {init, cleanup, setmode, getmode};
-static struct vid_modeinfo *modes;
-static int num_modes;
 static unsigned int vbe_ver;
 
+static int cur_mode;
+
 
 void vid_register_vbe(void)
 {
+	drv.name = "vbe";
+	drv.prio = 2;
 	drv.ops = &drvops;
 
 	vid_drvlist[vid_numdrv++] = &drv;
@@ -42,6 +45,8 @@ static int init(void)
 	int i, count;
 	struct vid_modeinfo modeinf;
 
+	cur_mode = -1;
+
 	vbe = dpmi_lowbuf();
 	bufseg = (intptr_t)vbe >> 4;
 
@@ -57,7 +62,7 @@ static int init(void)
 
 	vbe_ver = vbe->ver;
 
-	printf("Found VBE %d.%d\n", vbe_ver >> 8, vbe_ver & 0xff);
+	printf("Found VBE %d.%d\n", VBE_VER_MAJOR(vbe_ver), VBE_VER_MINOR(vbe_ver));
 	printf("OEM: %s\n", (char*)farptr_to_linear(vbe->oem_name));
 	if(vbe_ver >= 0x0200) {
 		printf("%s - %s (%s)\n", (char*)farptr_to_linear(vbe->vendor),
@@ -81,31 +86,59 @@ static int init(void)
 		modelist[i] = vbe_modelist[i];
 	}
 
-	printf("found %d modes\n", count);
-	return 0;
-	num_modes = 0;
+	if(!(drv.modes = malloc(count * sizeof *drv.modes))) {
+		fprintf(stderr, "failed to allocate mode list\n");
+		free(modelist);
+		return -1;
+	}
+
+	drv.num_modes = 0;
 	for(i=0; i<count; i++) {
 		if(get_mode_info(modelist[i], &vbemi) == -1) {
 			continue;
 		}
-		conv_vbeinfo(modelist[i], modes + num_modes++, &vbemi);
+		if(conv_vbeinfo(modelist[i], drv.modes + drv.num_modes, &vbemi) == -1) {
+			continue;
+		}
+		drv.num_modes++;
 	}
 
+	free(modelist);
 	return 0;
 }
 
 static void cleanup(void)
 {
+	free(drv.modes);
+	drv.modes = 0;
+	drv.num_modes = 0;
 }
 
 static int setmode(int mode)
 {
-	return -1;
+	struct dpmi_regs regs = {0};
+
+	regs.eax = 0x4f02;
+	regs.ebx = mode | VBE_MODE_LFB;
+	dpmi_rmint(0x10, &regs);
+
+	if(regs.eax != 0x4f) {
+		regs.eax = 0x4f02;
+		regs.ebx = mode;
+		dpmi_rmint(0x10, &regs);
+		if(regs.eax != 0x4f) {
+			return -1;
+		}
+		cur_mode = mode;
+	} else {
+		cur_mode = mode | VBE_MODE_LFB;
+	}
+	return 0;
 }
 
 static int getmode(void)
 {
-	return -1;
+	return cur_mode;
 }
 
 static const char *memsize_str(long sz)
@@ -149,17 +182,47 @@ static int conv_vbeinfo(int mode, struct vid_modeinfo *mi, struct vbe_mode_info
 	static const struct { int width, height, bpp; } stdmode[] = {
 		{640, 400, 8},		/* 100h */
 		{640, 480, 8},		/* 101h */
-		{800, 600, 4},		/* 102h */
-		{800, 600, 8},		/* 103h */
-		{1024, 768, 4},		/* 104h */
-		{1024, 768, 8},		/* 105h */
-		{1280, 1024, 4},	/* 106h */
-		{1280, 1024, 8}		/* 107h */
+		{800, 600, 4}, {800, 600, 8},		/* 102h - 103h */
+		{1024, 768, 4}, {1024, 768, 8},		/* 104h - 105h */
+		{1280, 1024, 4}, {1280, 1024, 8},	/* 106h - 107h */
+		{80, 60, 4}, {132, 25, 4}, {132, 43, 4}, {132, 50, 4}, {132, 60, 4},
+		{320, 200, 15}, {320, 200, 16}, {320, 200, 24},	/* 10dh - 10fh */
+		{640, 480, 15}, {640, 480, 16}, {640, 480, 24},	/* 110h - 112h */
+		{800, 600, 15}, {800, 600, 16}, {800, 600, 24},	/* 113h - 115h */
+		{1024, 768, 15}, {1024, 768, 16}, {1024, 768, 24}, /* 116h - 118h */
+		{1280, 1024, 15}, {1280, 1024, 16}, {1280, 1024, 24} /* 119h - 11bh */
 	};
+
+	if(!(vbemi->attr & VBE_ATTR_AVAIL)) {
+		return -1;	/* ignore unsupported modes */
+	}
+	if(!(vbemi->attr & VBE_ATTR_GFX)) {
+		return -1;	/* ignore text modes */
+	}
+	if(vbemi->attr & VBE_ATTR_LFB) {
+		mi->lfb = 1;
+	}
+
+	mi->drv = &drv;
+	mi->modeno = mode;
+	mi->vmem_addr = 0xa0000;
+
 	if(vbe_ver >= 0x0102) {
 		mi->width = vbemi->xres;
 		mi->height = vbemi->yres;
 		mi->bpp = vbemi->bpp;
+		mi->rshift = vbemi->rpos;
+		mi->gshift = vbemi->gpos;
+		mi->bshift = vbemi->bpos;
+		mi->rmask = calc_mask(vbemi->rsize, vbemi->rpos);
+		mi->gmask = calc_mask(vbemi->gsize, vbemi->gpos);
+		mi->bmask = calc_mask(vbemi->bsize, vbemi->bpos);
+		mi->pages = vbemi->num_img_pages + 1;
+
+		if(vbe_ver >= 0x0200) {
+			mi->vmem_addr = vbemi->fb_addr;
+			mi->vmem_size = vbemi->scanline_bytes * mi->height * mi->pages;
+		}
 	} else {
 		if((mode & 0xff) > 7) {
 			return -1;
@@ -168,5 +231,20 @@ static int conv_vbeinfo(int mode, struct vid_modeinfo *mi, struct vbe_mode_info
 		mi->height = stdmode[mode & 0xff].height;
 		mi->bpp = stdmode[mode & 0xff].bpp;
 	}
+	mi->ncolors = 1 << mi->bpp;
+	mi->pitch = vbemi->scanline_bytes;
+	mi->win_size = vbemi->win_size;
+	mi->win_gran = vbemi->win_gran;
 	return 0;
 }
+
+static unsigned int calc_mask(int nbits, int pos)
+{
+	int i;
+	unsigned int mask = 0;
+
+	for(i=0; i<nbits; i++) {
+		mask = (mask << 1) | 1;
+	}
+	return mask << pos;
+}
diff --git a/vidsys.c b/vidsys.c
index 43913c8..66f6811 100644
--- a/vidsys.c
+++ b/vidsys.c
@@ -42,7 +42,7 @@ int vid_init(void)
 
 		for(j=0; j<drv->num_modes; j++) {
 			if(num_modes >= max_modes) {
-				int newsz = max_modes ? max_modes * 2 : 8;
+				int newsz = max_modes ? max_modes * 2 : 128;
 				void *tmp = realloc(modes, newsz * sizeof *modes);
 				if(!tmp) {
 					fprintf(stderr, "failed to allocate modes list\n");
diff --git a/vidsys.h b/vidsys.h
index f2e308c..34e35ed 100644
--- a/vidsys.h
+++ b/vidsys.h
@@ -40,13 +40,15 @@ struct vid_driver {
 
 struct vid_modeinfo {
 	int modeno;
-	int width, height, bpp, ncolors;
+	int width, height, bpp, pitch;
+	int ncolors;
 	uint32_t rmask, gmask, bmask;
 	int rshift, gshift, bshift;
 	int pages;
 	int win_size, win_gran;
 	uint32_t vmem_addr;
 	size_t vmem_size;
+	int lfb;
 
 	struct vid_driver *drv;
 	struct vid_gfxops ops;
-- 
1.7.10.4