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Diffstat (limited to 'src/kernel/arch/amd64/tty/vga.c')
-rw-r--r--src/kernel/arch/amd64/tty/vga.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/src/kernel/arch/amd64/tty/vga.c b/src/kernel/arch/amd64/tty/vga.c
new file mode 100644
index 0000000..e5f2274
--- /dev/null
+++ b/src/kernel/arch/amd64/tty/vga.c
@@ -0,0 +1,33 @@
+#include <kernel/arch/amd64/tty/tty.h>
+
+struct vga_cell {
+ unsigned char c;
+ unsigned char style;
+} __attribute__((__packed__));
+
+static const size_t vga_len = 80 * 25;
+static struct vga_cell *vga = (void*) 0xB8000;
+static size_t vga_pos = 0;
+
+static void vga_scroll(void) {
+ for (size_t i = 0; i < vga_len - 80; i++)
+ vga[i] = vga[i + 80];
+ vga_pos -= 80;
+}
+
+static void vga_putchar(char c) {
+ if (vga_pos >= vga_len - 80)
+ vga_scroll();
+ vga[vga_pos++].c = c;
+}
+
+void vga_write(const char *buf, size_t len) {
+ for (size_t i = 0; i < len; i++)
+ vga_putchar(buf[i]);
+}
+
+void vga_clear(void) {
+ for (size_t i = 0; i < vga_len; i++)
+ vga[i].c = ' ';
+ vga_pos = 0;
+}