[SeaBIOS] [PATCH 2/2] vgahw: fallback to stdvga when cirrus / bochs detection fails

[Gerd Hoffmann]

Happens in case a vga with bochs interface lives behind a pci bridge.
stdvga ports are passed through with vgasnoop enabled, bochs interface
ports are not.  Better fallback to stdvga (so text mode works as usual)
rather than bailing out.

Signed-off-by: Gerd Hoffmann 
---
 vgasrc/vgahw.c | 67 ++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 37 insertions(+), 30 deletions(-)

diff --git a/vgasrc/vgahw.c b/vgasrc/vgahw.c
index fc843c4..95482df 100644
--- a/vgasrc/vgahw.c
+++ b/vgasrc/vgahw.c
@@ -6,122 +6,129 @@
 #include "stdvga.h" // stdvga_set_mode
 #include "geodevga.h" // geodevga_setup

+static int CirrusDetected VAR16 = 0;
+static int BochsDetected VAR16 = 0;
+
 struct vgamode_s *vgahw_find_mode(int mode) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_find_mode(mode);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_find_mode(mode);
     return stdvga_find_mode(mode);
 }

int vgahw_set_mode(struct vgamode_s *vmode_g, int flags) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_set_mode(vmode_g, flags);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_set_mode(vmode_g, flags);
     return stdvga_set_mode(vmode_g, flags);
 }

void vgahw_list_modes(u16 seg, u16 *dest, u16 *last) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         clext_list_modes(seg, dest, last);
-    else if (CONFIG_VGA_BOCHS)
+    else if (CONFIG_VGA_BOCHS && BochsDetected)
         bochsvga_list_modes(seg, dest, last);
     else
         stdvga_list_modes(seg, dest, last);
 }

int vgahw_setup(void) {
-    if (CONFIG_VGA_CIRRUS)
-        return clext_setup();
-    if (CONFIG_VGA_BOCHS)
-        return bochsvga_setup();
+    if (CONFIG_VGA_CIRRUS && clext_setup() == 0) {
+        CirrusDetected = 1;
+        return 0;
+    }
+    if (CONFIG_VGA_BOCHS && bochsvga_setup() == 0) {
+        BochsDetected = 1;
+        return 0;
+    }
     if (CONFIG_VGA_GEODEGX2 || CONFIG_VGA_GEODELX)
         return geodevga_setup();
     return stdvga_setup();
 }

int vgahw_get_window(struct vgamode_s *vmode_g, int window) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_get_window(vmode_g, window);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_get_window(vmode_g, window);
     return stdvga_get_window(vmode_g, window);
 }

int vgahw_set_window(struct vgamode_s *vmode_g, int window
                                    , int val) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_set_window(vmode_g, window, val);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_set_window(vmode_g, window, val);
     return stdvga_set_window(vmode_g, window, val);
 }

int vgahw_get_linelength(struct vgamode_s *vmode_g) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_get_linelength(vmode_g);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_get_linelength(vmode_g);
     return stdvga_get_linelength(vmode_g);
 }

int vgahw_set_linelength(struct vgamode_s *vmode_g, int val) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_set_linelength(vmode_g, val);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_set_linelength(vmode_g, val);
     return stdvga_set_linelength(vmode_g, val);
 }

int vgahw_get_displaystart(struct vgamode_s *vmode_g) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_get_displaystart(vmode_g);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_get_displaystart(vmode_g);
     return stdvga_get_displaystart(vmode_g);
 }

int vgahw_set_displaystart(struct vgamode_s *vmode_g, int val) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_set_displaystart(vmode_g, val);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_set_displaystart(vmode_g, val);
     return stdvga_set_displaystart(vmode_g, val);
 }

int vgahw_get_dacformat(struct vgamode_s *vmode_g) {
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_get_dacformat(vmode_g);
     return stdvga_get_dacformat(vmode_g);
 }

int vgahw_set_dacformat(struct vgamode_s *vmode_g, int val) {
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_set_dacformat(vmode_g, val);
     return stdvga_set_dacformat(vmode_g, val);
 }

int vgahw_size_state(int states) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_size_state(states);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_size_state(states);
     return stdvga_size_state(states);
 }

int vgahw_save_state(u16 seg, void *data, int states) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_save_state(seg, data, states);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_save_state(seg, data, states);
     return stdvga_save_state(seg, data, states);
 }

int vgahw_restore_state(u16 seg, void *data, int states) {
-    if (CONFIG_VGA_CIRRUS)
+    if (CONFIG_VGA_CIRRUS && CirrusDetected)
         return clext_restore_state(seg, data, states);
-    if (CONFIG_VGA_BOCHS)
+    if (CONFIG_VGA_BOCHS && BochsDetected)
         return bochsvga_restore_state(seg, data, states);
     return stdvga_restore_state(seg, data, states);
 }