initial hasty attempt at porting over my VBE code

[bootcensus] / src / vbe.c

diff --git a/src/vbe.c b/src/vbe.c
new file mode 100644 (file)
index 0000000..58cf2e7
--- /dev/null
+++ b/src/vbe.c
@@ -0,0 +1,81 @@
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include "vbe.h"
+#include "asmops.h"
+#include "int86.h"
+
+#define SEG_ADDR(s)    ((uint32_t)(s) << 4)
+
+#define MODE_LFB       (1 << 14)
+
+extern void *low_mem_buffer;
+
+struct vbe_info *vbe_get_info(void)
+{
+       struct vbe_info *info;
+       struct int86regs regs;
+
+       info = low_mem_buffer;
+
+       memcpy(info->sig, "VBE2", 4);
+
+       memset(&regs, 0, sizeof regs);
+       regs.es = (uint32_t)low_mem_buffer >> 4;
+       regs.eax = 0x4f00;
+       int86(0x10, &regs);
+
+       return info;
+}
+
+struct vbe_mode_info *vbe_get_mode_info(int mode)
+{
+       struct vbe_mode_info *mi;
+       struct int86regs regs;
+
+       mi = low_mem_buffer;
+
+       memset(&regs, 0, sizeof regs);
+       regs.es = (uint32_t)low_mem_buffer >> 4;
+       regs.eax = 0x4f01;
+       regs.ecx = mode;
+       int86(0x10, &regs);
+
+       if(regs.eax & 0xff00) {
+               return 0;
+       }
+
+       return mi;
+}
+
+int vbe_set_mode(int mode)
+{
+       struct int86regs regs;
+
+       memset(&regs, 0, sizeof regs);
+       regs.eax = 0x4f02;
+       regs.ebx = mode;
+       int86(0x10, &regs);
+
+       if(regs.eax == 0x100) {
+               return -1;
+       }
+       return 0;
+}
+
+void print_mode_info(struct vbe_mode_info *mi)
+{
+       static unsigned int maskbits[] = {0, 1, 3, 7, 0xf, 0x1f, 0x3f, 0x7f, 0xff};
+
+       printf("resolution: %dx%d\n", mi->xres, mi->yres);
+       printf("color depth: %d\n", mi->bpp);
+       printf("mode attributes: %x\n", mi->mode_attr);
+       printf("bytes per scanline: %d\n", mi->scanline_bytes);
+       printf("number of planes: %d\n", (int)mi->num_planes);
+       printf("number of banks: %d\n", (int)mi->num_banks);
+       printf("mem model: %d\n", (int)mi->mem_model);
+       printf("red bits: %d (mask: %x)\n", (int)mi->rmask_size, maskbits[mi->rmask_size] << mi->rpos);
+       printf("green bits: %d (mask: %x)\n", (int)mi->gmask_size, maskbits[mi->gmask_size] << mi->gpos);
+       printf("blue bits: %d (mask: %x)\n", (int)mi->bmask_size, maskbits[mi->bmask_size] << mi->bpos);
+       printf("framebuffer address: %x\n", (unsigned int)mi->fb_addr);
+}