[src/trunk]: src/sys/arch/i386/stand/lib PR/54767: elo: fix incorrect test (m...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2a938b6a398a
branches:  trunk
changeset: 847218:2a938b6a398a
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Dec 15 03:38:17 2019 +0000

description:
PR/54767: elo: fix incorrect test (mlelstv)
Add symbolic constants and reference to the standard.

diffstat:

 sys/arch/i386/stand/lib/vbe.c |  52 +++++++++++++++++++++++++++++++++++++-----
 1 files changed, 45 insertions(+), 7 deletions(-)

diffs (73 lines):

diff -r acd8f0604022 -r 2a938b6a398a sys/arch/i386/stand/lib/vbe.c
--- a/sys/arch/i386/stand/lib/vbe.c     Sun Dec 15 02:58:21 2019 +0000
+++ b/sys/arch/i386/stand/lib/vbe.c     Sun Dec 15 03:38:17 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: vbe.c,v 1.9 2017/01/24 11:09:14 nonaka Exp $ */
+/* $NetBSD: vbe.c,v 1.10 2019/12/15 03:38:17 christos Exp $ */
 
 /*-
  * Copyright (c) 2009 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -45,19 +45,57 @@
        int             modenum;
 } vbestate;
 
+/*
+ * https://pdos.csail.mit.edu/6.828/2018/readings/hardware/vbe3.pdf
+ * p32
+ */
+#define        VBE_MODEATTR_MODE_HARDWARE_SUPPORTED            0x0001u
+#define        VBE_MODEATTR_RESERVED_1                         0x0002u
+#define        VBE_MODEATTR_TTY_OUTPUT_FUNCTIONS_SUPPORTED     0x0004u
+#define        VBE_MODEATTR_COLOR_MODE                         0x0008u
+#define        VBE_MODEATTR_GRAPHICS_MODE                      0x0010u
+#define        VBE_MODEATTR_VGA_COMPATIBLE_MODE                0x0020u
+#define        VBE_MODEATTR_VGA_COMPATIBLE_WINDOWD_MEMORY_MODE 0x0040u
+#define        VBE_MODEATTR_LINEAR_FRAME_BUFFER_MODE           0x0080u
+#define        VBE_MODEATTR_DOUBLE_SCAN_MODE                   0x0100u
+#define        VBE_MODEATTR_INTERLACED_MODE                    0x0200u
+#define        VBE_MODEATTR_HARDWARE_TRIPPLE_BUFFERING_SUPPORT 0x0400u
+#define        VBE_MODEATTR_HARDWARE_STEREOSCOPIC_SUPPORT      0x0800u
+#define        VBE_MODEATTR_DUAL_DISPLAY_START_ADDRESS_SUPPORT 0x1000u
+#define        VBE_MODEATTR_RESERVED_2                         0x2000u
+#define        VBE_MODEATTR_RESERVED_3                         0x4000u
+#define        VBE_MODEATTR_RESERVED_4                         0x8000u
+
+/*
+ * p36
+ */
+#define VBE_MEMMODEL_TEXT              0x00u
+#define        VBE_MEMMODEL_CGA                0x01u
+#define        VBE_MEMMODEL_HERCULES           0x02u
+#define        VBE_MEMMODEL_PLANAR             0x03u
+#define        VBE_MEMMODEL_PACKED_PIXEL       0x04u
+#define        VBE_MEMMODEL_NON_CHAIN_4_256    0x05u
+#define        VBE_MEMMODEL_DIRECT_COLOR       0x06u
+#define        VBE_MEMMODEL_YUV                0x07u
+/* VESA Reserved                       0x08u-0x0fu */
+/* OEM Reserved                                0x10u-0xffU */
+
+
 static int
 vbe_mode_is_supported(struct modeinfoblock *mi)
 {
-       if ((mi->ModeAttributes & 0x01) == 0)
+       if ((mi->ModeAttributes & VBE_MODEATTR_MODE_HARDWARE_SUPPORTED) == 0)
                return 0;       /* mode not supported by hardware */
-       if ((mi->ModeAttributes & 0x08) == 0)
+       if ((mi->ModeAttributes & VBE_MODEATTR_COLOR_MODE) == 0)
+               return 0;       /* only color modes are supported */
+       if ((mi->ModeAttributes & VBE_MODEATTR_GRAPHICS_MODE) == 0)
+               return 0;       /* text mode */
+       if ((mi->ModeAttributes & VBE_MODEATTR_LINEAR_FRAME_BUFFER_MODE) == 0)
                return 0;       /* linear fb not available */
-       if ((mi->ModeAttributes & 0x10) == 0)
-               return 0;       /* text mode */
        if (mi->NumberOfPlanes != 1)
                return 0;       /* planar mode not supported */
-       if (mi->MemoryModel != 0x04 /* Packed pixel */ &&
-           mi->MemoryModel != 0x06 /* Direct Color */)
+       if (mi->MemoryModel != VBE_MEMMODEL_PACKED_PIXEL /* Packed pixel */ &&
+           mi->MemoryModel != VBE_MEMMODEL_DIRECT_COLOR /* Direct Color */)
                return 0;       /* unsupported pixel format */
        return 1;
 }