From 25de7c1b120b83598170e6be810058447db802fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Revol?= <revol@free.fr>
Date: Wed, 8 May 2019 04:32:08 +0200
Subject: [PATCH] loader: VESA: make nvidia scaling fixup a driver setting

Since not everyone likes the default, make it an option in the vesa
settings file. Note setting a mode with the Screen prefs overwrites
the file so it will discard the option.

Also move the code to get_mode_from_settings() since we can't load driver
settings as early as vesa_init().

Change-Id: I93080bd1fbc064dab053624ad37935268b1ed17d
---
 data/settings/kernel/drivers/vesa            |  5 +++
 src/system/boot/platform/bios_ia32/video.cpp | 47 ++++++++++++--------
 2 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/data/settings/kernel/drivers/vesa b/data/settings/kernel/drivers/vesa
index 80a1366263..141193f28d 100644
--- a/data/settings/kernel/drivers/vesa
+++ b/data/settings/kernel/drivers/vesa
@@ -2,3 +2,8 @@
 # mode {x-resolution} {y-resolution} {bitdepth},
 #   for example:
 #mode 1280 1024 32
+
+# Set NVIDIA scaling mode
+# 1: disable scaling completely
+# other modes are available depending on the BIOS
+#nvidia_scaling 1
diff --git a/src/system/boot/platform/bios_ia32/video.cpp b/src/system/boot/platform/bios_ia32/video.cpp
index 4a719478f7..220db2d5a3 100644
--- a/src/system/boot/platform/bios_ia32/video.cpp
+++ b/src/system/boot/platform/bios_ia32/video.cpp
@@ -258,6 +258,33 @@ find_edid_mode(edid1_info& info, bool allowPalette)
 }
 
 
+static void
+vesa_fixups(void *settings)
+{
+	const char *oem_string = (const char *)sInfo.oem_string;
+
+	if (!strcmp(oem_string, "NVIDIA")) {
+		const char *arg = NULL;
+		int32 scaling = -1;
+
+		if (settings != NULL)
+			arg = get_driver_parameter(settings, "nvidia_scaling", NULL, "1");
+		if (arg != NULL)
+			scaling = strtol(arg, NULL, 0);
+
+		if (scaling > -1) {
+			dprintf("Setting nvidia scaling mode to %" B_PRId32 "\n", scaling);
+			struct bios_regs regs;
+			regs.eax = 0x4f14;
+			regs.ebx = 0x0102;
+			regs.ecx = scaling;
+			call_bios(0x10, &regs);
+		}
+	}
+
+}
+
+
 static bool
 get_mode_from_settings(void)
 {
@@ -268,6 +295,8 @@ get_mode_from_settings(void)
 	if (handle == NULL)
 		return false;
 
+	vesa_fixups(handle);
+
 	bool found = false;
 
 	const driver_settings *settings = get_driver_settings(handle);
@@ -439,30 +468,12 @@ vesa_get_vbe_info_block(vbe_info_block *info)
 }
 
 
-static void
-vesa_fixups(vbe_info_block *info)
-{
-	const char *oem_string = (const char *)info->oem_string;
-
-	if (!strcmp(oem_string, "NVIDIA")) {
-		dprintf("Disabling nvidia scaling.\n");
-		struct bios_regs regs;
-		regs.eax = 0x4f14;
-		regs.ebx = 0x0102;
-		regs.ecx = 1;	// centered unscaled
-		call_bios(0x10, &regs);
-	}
-}
-
-
 static status_t
 vesa_init(vbe_info_block *info, video_mode **_standardMode)
 {
 	if (vesa_get_vbe_info_block(info) != B_OK)
 		return B_ERROR;
 
-	vesa_fixups(info);
-
 	// fill mode list and find standard video mode
 
 	video_mode *standardMode = NULL;