font rending in framebuffer yay!!

2 files changed, 217 insertions, 0 deletions

diff --git a/kernel/drivers/gpu.c b/kernel/drivers/gpu.c
new file mode 100644
index 0000000..7ecdada
--- /dev/null
+++ b/kernel/drivers/gpu.c
@@ -0,0 +1,119 @@
+#include <lib.h>
+#include <comus/drivers/gpu.h>
+#include <comus/drivers/gpu/bochs.h>
+#include <comus/error.h>
+#include <comus/term.h>
+#include <comus/asm.h>
+
+enum gpu_type {
+	GPU_UNSET = 0,
+	GPU_BOCHS = 1,
+	N_GPU_TYPE,
+};
+
+static enum gpu_type type = GPU_UNSET;
+
+static const char *gpu_type_str[N_GPU_TYPE] = {
+	"Unknown", "Bochs"
+};
+
+struct psf2_font {
+	uint8_t magic[4];
+	uint32_t version;
+	uint32_t header_size;
+	uint32_t flags;
+	uint32_t length;
+	uint32_t glyph_size;
+	uint32_t height;
+	uint32_t width;
+	uint8_t data[];
+};
+
+extern struct psf2_font en_font;
+
+int gpu_init(void)
+{
+	if (bochs_init() == SUCCESS)
+		type = GPU_BOCHS;
+
+	if (type != GPU_UNSET) {
+		uint16_t width = gpu_width() / en_font.width;
+		uint16_t height = gpu_height() / en_font.height;
+		term_switch_handler(width, height, gpu_draw_char);
+	}
+
+	return type != GPU_UNSET;
+}
+
+uint32_t gpu_width(void)
+{
+	switch (type) {
+	case GPU_BOCHS:
+		return bochs_width();
+	default:
+		return 0;
+	}
+}
+
+uint32_t gpu_height(void)
+{
+	switch (type) {
+	case GPU_BOCHS:
+		return bochs_height();
+	default:
+		return 0;
+	}
+}
+
+uint8_t gpu_bit_depth(void)
+{
+	switch (type) {
+	case GPU_BOCHS:
+		return bochs_bit_depth();
+	default:
+		return 0;
+	}
+}
+
+void gpu_set_pixel(uint32_t x, uint32_t y, uint32_t r, uint32_t g, uint32_t b)
+{
+	switch (type) {
+	case GPU_BOCHS:
+		bochs_set_pixel(x, y, r, g, b);
+		break;
+	default:
+		break;
+	}
+}
+
+void gpu_draw_char(char c, uint16_t cx, uint16_t cy)
+{
+	uint32_t sx = en_font.width * cx;
+	uint32_t sy = en_font.height * cy;
+
+	uint8_t *glyph = &en_font.data[en_font.glyph_size * c];
+
+	for (uint32_t i = 0; i < en_font.width; i++) {
+		for (uint32_t j = 0; j < en_font.height; j++) {
+			uint32_t x = sx + (en_font.width - i - 1);
+			uint32_t y = sy + j;
+			uint32_t bitoff = i + j * en_font.width;
+			uint32_t byteoff = bitoff / 8;
+			uint32_t bitshift = bitoff % 8;
+
+			uint32_t color = ((glyph[byteoff] >> bitshift) & 0x1) * 255;
+			gpu_set_pixel(x, y, color, color, color);
+		}
+	}
+}
+
+void gpu_report(void)
+{
+	if (type == GPU_UNSET)
+		return;
+
+	kprintf("GPU (%s)\n", gpu_type_str[type]);
+	kprintf("Width: %d\n", gpu_width());
+	kprintf("Height: %d\n", gpu_height());
+	kprintf("Bit depth: %d\n\n", gpu_bit_depth());
+}
diff --git a/kernel/drivers/gpu/bochs.c b/kernel/drivers/gpu/bochs.c
new file mode 100644
index 0000000..5b0f1fc
--- /dev/null
+++ b/kernel/drivers/gpu/bochs.c
@@ -0,0 +1,98 @@
+#include <lib.h>
+#include <comus/asm.h>
+#include <comus/memory.h>
+#include <comus/drivers/pci.h>
+#include <comus/drivers/gpu/bochs.h>
+
+#define INDEX           0x1CE
+#define DATA            0x1CF
+
+#define INDEX_ID            0
+#define INDEX_XRES          1
+#define INDEX_YRES          2
+#define INDEX_BPP           3
+#define INDEX_ENABLE        4
+#define INDEX_BANK          5
+#define INDEX_VIRT_WIDTH    6
+#define INDEX_VIRT_HEIGHT   7
+#define INDEX_X_OFFSET      8
+#define INDEX_Y_OFFSET      9
+
+#define DATA_DISP_DISABLE   0x00
+#define DATA_DISP_ENABLE    0x01
+#define DATA_LFB_ENABLE     0x40
+#define DATA_NO_CLEAR_MEM   0x80
+
+#define BOCHS_PCI_VENDOR    0x1234
+#define BOCHS_PCI_DEVICE    0x1111
+
+#define BOCHS_WIDTH 1024
+#define BOCHS_HEIGHT 768
+#define BOCHS_BIT_DEPTH 32
+
+static volatile uint32_t *framebuffer;
+static uint16_t width = BOCHS_WIDTH;
+static uint16_t height = BOCHS_HEIGHT;
+static uint8_t bit_depth = BOCHS_BIT_DEPTH;
+
+static void write(uint16_t index, uint16_t data) {
+	outw(INDEX, index);
+	outw(DATA, data);
+}
+
+static uint16_t read(uint16_t value) {
+	outw(INDEX, value);
+	return inw(DATA);
+}
+
+static int is_available(void) {
+	return (read(INDEX_ID) == 0xB0C5);
+}
+
+static void set_mode(uint16_t width, uint16_t height, uint16_t bit_depth, int lfb, int clear) {
+	write(INDEX_ENABLE, DATA_DISP_DISABLE);
+	write(INDEX_XRES, width);
+	write(INDEX_YRES, height);
+	write(INDEX_BPP, bit_depth);
+	write(INDEX_ENABLE, DATA_DISP_ENABLE |
+			(lfb ? DATA_LFB_ENABLE : 0) |
+			(clear ? 0 : DATA_NO_CLEAR_MEM));
+}
+
+int bochs_init(void) {
+	struct pci_device bochs = {0};
+	bool found = pci_findby_id(&bochs, BOCHS_PCI_DEVICE, BOCHS_PCI_VENDOR, NULL);
+	if (!found)
+		return 1;
+
+	set_mode(width, height, bit_depth, true, true);
+	if (!is_available())
+		return 1;
+
+	uint32_t bar0 = pci_rcfg_d(bochs, PCI_BAR0_D);
+	uint32_t *addr = (uint32_t *) (uintptr_t) bar0;
+	framebuffer = kmapaddr(addr, NULL, width * height * bit_depth, F_WRITEABLE);
+
+	return 0;
+}
+
+uint32_t bochs_width(void)
+{
+	return width;
+}
+
+uint32_t bochs_height(void)
+{
+	return height;
+}
+
+uint8_t bochs_bit_depth(void)
+{
+	return bit_depth;
+}
+
+void bochs_set_pixel(uint32_t x, uint32_t y, uint32_t r, uint32_t g, uint32_t b)
+{
+	uint32_t index = x + y * width;
+	framebuffer[index] = (b << 0) | (g << 8) | (r << 16);
+}