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authorIan McFarlane <i.mcfarlane2002@gmail.com>2025-04-17 14:19:40 -0400
committerIan McFarlane <i.mcfarlane2002@gmail.com>2025-04-17 14:19:40 -0400
commit7108e7c951f7cff79ce4992f1c7d8d0af0bb5af6 (patch)
treee99684b87952bded5e51c83848a5d35ab53d9ab0 /kernel/drivers/gpu/bochs.c
parentstarting on ata (diff)
parentclang 18 in flake instead of zig (diff)
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Merge branch 'main' into ata
Diffstat (limited to 'kernel/drivers/gpu/bochs.c')
-rw-r--r--kernel/drivers/gpu/bochs.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/kernel/drivers/gpu/bochs.c b/kernel/drivers/gpu/bochs.c
new file mode 100644
index 0000000..a100908
--- /dev/null
+++ b/kernel/drivers/gpu/bochs.c
@@ -0,0 +1,104 @@
+#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);
+}