vesainfo: program to dump all VESA modes

2 files changed, 84 insertions, 1 deletions

diff --git a/com32/samples/Makefile b/com32/samples/Makefile
index 214c0c71..213ae1a3 100644
--- a/com32/samples/Makefile
+++ b/com32/samples/Makefile
@@ -38,7 +38,7 @@ LNXLIBS	   = ../libutil/libutil_lnx.a
 
 .SUFFIXES: .lss .c .o .elf .c32 .lnx
 
-all: 	hello.c32 cat.c32 resolv.c32 \
+all: 	hello.c32 cat.c32 resolv.c32 vesainfo.c32 \
 	fancyhello.c32 fancyhello.lnx \
 	keytest.c32 keytest.lnx \
 
diff --git a/com32/samples/vesainfo.c b/com32/samples/vesainfo.c
new file mode 100644
index 00000000..a1f00299
--- /dev/null
+++ b/com32/samples/vesainfo.c
@@ -0,0 +1,83 @@
+/*
+ * vesainfo.c
+ *
+ * Dump information about what VESA graphics modes are supported.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <console.h>
+#include <com32.h>
+#include <inttypes.h>
+#include "../lib/sys/vesa/vesa.h"
+
+/* Wait for a keypress */
+static void wait_key(void)
+{
+  char ch;
+  while (fread(&ch, 1, 1, stdin) == 0)
+    ;
+}
+
+static void print_modes(void)
+{
+  static com32sys_t rm;
+  struct vesa_general_info *gi;
+  struct vesa_mode_info *mi;
+  uint16_t mode, *mode_ptr;
+  int lines;
+
+  /* Allocate space in the bounce buffer for these structures */
+  gi = &((struct vesa_info *)__com32.cs_bounce)->gi;
+  mi = &((struct vesa_info *)__com32.cs_bounce)->mi;
+
+  gi->signature = VBE2_MAGIC;	/* Get VBE2 extended data */
+  rm.eax.w[0] = 0x4F00;		/* Get SVGA general information */
+  rm.edi.w[0] = OFFS(gi);
+  rm.es      = SEG(gi);
+  __intcall(0x10, &rm, &rm);
+
+  if ( rm.eax.w[0] != 0x004F ) {
+    printf("No VESA BIOS detected\n");
+    return;
+  } else if ( gi->signature != VESA_MAGIC ) {
+    printf("VESA information structure has bad magic, trying anyway...\n");
+  }
+
+  printf("VBE version %d.%d\n"
+	 "Mode   attrib h_res v_res bpp layout rpos gpos bpos\n",
+	 (gi->version >> 8) & 0xff, gi->version & 0xff);
+
+  lines = 1;
+
+  mode_ptr = GET_PTR(gi->video_mode_ptr);
+
+  while ((mode = *mode_ptr++) != 0xFFFF) {
+    if (++lines >= 23) {
+      wait_key();
+      lines = 0;
+    }
+
+    rm.eax.w[0] = 0x4F01;	/* Get SVGA mode information */
+    rm.ecx.w[0] = mode;
+    rm.edi.w[0] = OFFS(mi);
+    rm.es  = SEG(mi);
+    __intcall(0x10, &rm, &rm);
+
+    /* Must be a supported mode */
+    if ( rm.eax.w[0] != 0x004f )
+      continue;
+
+    printf("0x%04x 0x%04x %5u %5u %3u %6u %4u %4u %4u\n",
+	   mode, mi->mode_attr, mi->h_res, mi->v_res, mi->bpp,
+	   mi->memory_layout, mi->rpos, mi->gpos, mi->bpos);
+  }
+}
+
+int main(void)
+{
+  openconsole(&dev_rawcon_r, &dev_stdcon_w);
+
+  print_modes();
+  return 0;
+}