Add stubs for VIA vga bios callbacks to system bios.

The VIA vga bios likes wants to call int 15/5f of main bios.  So, add
    stubs to make it happy.

1 files changed, 65 insertions, 0 deletions

diff --git a/src/vgahooks.c b/src/vgahooks.c
new file mode 100644
index 0000000..7c229ba
--- /dev/null
+++ b/src/vgahooks.c
@@ -0,0 +1,65 @@
+// Hooks for via vgabios calls into main bios.
+//
+// Copyright (C) 2008  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "bregs.h" // set_fail
+#include "util.h" // handle_155f
+#include "config.h" // CONFIG_*
+
+static void
+handle_155f01(struct bregs *regs)
+{
+    regs->eax = 0x5f;
+    regs->cl = 2; // panel type =  2 = 1024 * 768
+    set_success(regs);
+}
+
+static void
+handle_155f02(struct bregs *regs)
+{
+    regs->eax = 0x5f;
+    regs->bx = 2;
+    regs->cx = 0x401;  // PAL + crt only
+    regs->dx = 0;  // TV Layout - default
+    set_success(regs);
+}
+
+static void
+handle_155f18(struct bregs *regs)
+{
+    regs->eax = 0x5f;
+    regs->ebx = 0x545; // MCLK = 133, 32M frame buffer, 256 M main memory
+    regs->ecx = 0x060;
+    set_success(regs);
+}
+
+static void
+handle_155f19(struct bregs *regs)
+{
+    set_fail_silent(regs);
+}
+
+static void
+handle_155fXX(struct bregs *regs)
+{
+    set_code_fail(regs, RET_EUNSUPPORTED);
+}
+
+void
+handle_155f(struct bregs *regs)
+{
+    if (! CONFIG_VGAHOOKS) {
+        handle_155fXX(regs);
+        return;
+    }
+
+    switch (regs->al) {
+    case 0x01: handle_155f01(regs); break;
+    case 0x02: handle_155f02(regs); break;
+    case 0x18: handle_155f18(regs); break;
+    case 0x19: handle_155f19(regs); break;
+    default:   handle_155fXX(regs); break;
+    }
+}