1 files changed, 58 insertions, 0 deletions
diff --git a/kernel/features/psf.c b/kernel/features/psf.c
new file mode 100644
index 0000000..adf2aa2
--- /dev/null
+++ b/kernel/features/psf.c
@@ -0,0 +1,58 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+// PSF parser
+
+#include <def.h>
+#include <gui.h>
+#include <mem.h>
+#include <print.h>
+#include <psf.h>
+#include <vesa.h>
+
+// Verifies the PSF magics
+// Returns the PSF version or 0
+int psf_verify(char *data)
+{
+	struct psf1_header *header1 = (struct psf1_header *)data;
+	struct psf2_header *header2 = (struct psf2_header *)data;
+
+	if (header1->magic[0] == PSF1_MAGIC_0 && header1->magic[1] == PSF1_MAGIC_1)
+		return 1;
+	else if (header2->magic[0] == PSF2_MAGIC_0 && header2->magic[1] == PSF2_MAGIC_1 &&
+		 header2->magic[2] == PSF2_MAGIC_2 && header2->magic[3] == PSF2_MAGIC_3)
+		return 2;
+	else
+		return 0;
+}
+
+struct font *psf_parse(char *data)
+{
+	int version = psf_verify(data);
+
+	char *chars;
+	int height;
+	int width;
+	int char_size;
+
+	if (version == 1) {
+		chars = data + sizeof(struct psf1_header);
+		height = ((struct psf1_header *)data)->char_size;
+		width = 8;
+		char_size = ((struct psf1_header *)data)->char_size;
+	} else if (version == 2) {
+		chars = data + ((struct psf2_header *)data)->size;
+		height = ((struct psf2_header *)data)->height;
+		width = ((struct psf2_header *)data)->width;
+		char_size = ((struct psf2_header *)data)->char_size;
+	} else {
+		printf("Unknown font!\n");
+		return 0;
+	}
+
+	struct font *font = malloc(sizeof(*font));
+	font->chars = chars;
+	font->height = height;
+	font->width = width;
+	font->char_size = char_size;
+
+	return font;
+}