added read_cpuid and MTRR support checking before trying to set them

[retrobench] / src / dos / gfx.c

diff --git a/src/dos/gfx.c b/src/dos/gfx.c
index 80d965b..474a2e1 100644 (file)
--- a/src/dos/gfx.c
+++ b/src/dos/gfx.c
@@ -171,6 +171,7 @@ void *set_video_mode(int idx, int nbuf)
 {
        unsigned int mode;
        struct video_mode *vm = vmodes + idx;
+       struct cpuid_info cpu;
 
        if(curmode == vm) return vpgaddr[0];
 
@@ -226,8 +227,10 @@ void *set_video_mode(int idx, int nbuf)
 
                blit_frame = blit_frame_lfb;
 
-               print_mtrr();
-               enable_wrcomb(vm->fb_addr, fbsize);
+               if(read_cpuid(&cpu) != -1 && cpu.feat & CPUID_FEAT_MTRR) {
+                       print_mtrr();
+                       enable_wrcomb(vm->fb_addr, fbsize);
+               }
 
        } else {
                vpgaddr[0] = (void*)0xa0000;