dev: boot framebuffer support

arch/x86_64/include/socks/machine/init.h

@@ -16,6 +16,9 @@ extern "C" {
 
 extern int ml_init(uintptr_t arg);
 
+extern const struct framebuffer_varinfo *bootfb_varinfo(void);
+extern const struct framebuffer_fixedinfo *bootfb_fixedinfo(void);
+
 #ifdef __cplusplus
 }
 #endif

arch/x86_64/init.c

@@ -20,6 +20,8 @@
 #define PTR32(x) ((void *)((uintptr_t)(x)))
 
 static ml_cpu_block g_bootstrap_cpu = {0};
+static struct framebuffer_varinfo __bootfb_varinfo;
+static struct framebuffer_fixedinfo __bootfb_fixedinfo;
 
 /* start and end of kernel image (physical addresses) */
 extern char __pstart[], __pend[];
@@ -44,10 +46,51 @@ static void early_vm_init(void)
 	printk("memblock: reserved bios+kernel at [0x%016llx-0x%016llx]", 0, (uintptr_t)__pend);
 }
 
+static void init_bootfb(multiboot_info_t *mb)
+{
+	__bootfb_varinfo.fb_xres = mb->framebuffer_width;
+	__bootfb_varinfo.fb_yres = mb->framebuffer_height;
+	__bootfb_varinfo.fb_bpp = mb->framebuffer_bpp;
+	__bootfb_varinfo.fb_stride = mb->framebuffer_pitch;
+
+	switch (mb->framebuffer_type) {
+	case MULTIBOOT_FRAMEBUFFER_TYPE_INDEXED:
+		__bootfb_varinfo.fb_flags = FB_MODE_PALETTE;
+		__bootfb_varinfo.fb_palette_addr = mb->framebuffer_palette_addr;
+		__bootfb_varinfo.fb_palette_nr_colours = mb->framebuffer_palette_num_colors;
+		break;
+	case MULTIBOOT_FRAMEBUFFER_TYPE_RGB:
+		__bootfb_varinfo.fb_flags = FB_MODE_RGB;
+		__bootfb_varinfo.fb_red.b_length = mb->framebuffer_red_mask_size;
+		__bootfb_varinfo.fb_red.b_offset = mb->framebuffer_red_field_position;
+
+		__bootfb_varinfo.fb_green.b_length = mb->framebuffer_green_mask_size;
+		__bootfb_varinfo.fb_green.b_offset = mb->framebuffer_green_field_position;
+
+		__bootfb_varinfo.fb_blue.b_length = mb->framebuffer_blue_mask_size;
+		__bootfb_varinfo.fb_blue.b_offset = mb->framebuffer_blue_field_position;
+
+		__bootfb_varinfo.fb_alpha.b_length = 0;
+		__bootfb_varinfo.fb_alpha.b_offset = 0;
+		break;
+	case MULTIBOOT_FRAMEBUFFER_TYPE_EGA_TEXT:
+		__bootfb_varinfo.fb_flags = FB_MODE_VGATEXT;
+		__bootfb_varinfo.fb_xcells = 80;
+		__bootfb_varinfo.fb_ycells = 25;
+		break;
+	default:
+		break;
+	}
+
+	__bootfb_fixedinfo.fb_baseptr = mb->framebuffer_addr;
+}
+
 int ml_init(uintptr_t arg)
 {
 	multiboot_info_t *mb = (multiboot_info_t *)arg;
 
+	init_bootfb(mb);
+
 	bootstrap_cpu_init();
 	vgacon_init();
 	serialcon_init(115200);
@@ -56,6 +99,7 @@ int ml_init(uintptr_t arg)
 	print_kernel_banner();
 
 	early_vm_init();
+	printk("video mode: %ux%u", mb->framebuffer_width, mb->framebuffer_height);
 
 	e820_scan(PTR32(mb->mmap_addr), mb->mmap_length);
 
@@ -91,3 +135,13 @@ int ml_init(uintptr_t arg)
 
 	return 0;
 }
+
+const struct framebuffer_varinfo *bootfb_varinfo(void)
+{
+	return &__bootfb_varinfo;
+}
+
+const struct framebuffer_fixedinfo *bootfb_fixedinfo(void)
+{
+	return &__bootfb_fixedinfo;
+}

include/socks/device.h

@@ -70,7 +70,7 @@ struct bus_device_ops {
 };
 
 struct framebuffer_device_ops {
-	kern_status_t(*scan)(struct device *);
+	kern_status_t(*set_varinfo)(struct device *, const struct framebuffer_varinfo *);
 };
 
 struct block_device {

include/socks/fb.h

@@ -4,7 +4,9 @@
 #include <stdint.h>
 
 enum framebuffer_flags {
-	FB_VGATEXT = 0x01u,
+	FB_MODE_RGB = 0x01u,
+	FB_MODE_VGATEXT = 0x02u,
+	FB_MODE_PALETTE = 0x04u,
 };
 
 struct framebuffer_bitfield {
@@ -20,10 +22,24 @@ struct framebuffer_varinfo {
 	uint32_t fb_bpp;
 	uint32_t fb_stride;
 
-	struct framebuffer_bitfield fb_red;
-	struct framebuffer_bitfield fb_green;
-	struct framebuffer_bitfield fb_blue;
-	struct framebuffer_bitfield fb_alpha;
+	union {
+		struct {
+			uint32_t fb_xcells;
+			uint32_t fb_ycells;
+		};
+
+		struct {
+			struct framebuffer_bitfield fb_red;
+			struct framebuffer_bitfield fb_green;
+			struct framebuffer_bitfield fb_blue;
+			struct framebuffer_bitfield fb_alpha;
+		};
+
+		struct {
+			uintptr_t fb_palette_addr;
+			uint16_t fb_palette_nr_colours;
+		};
+	};
 };
 
 struct framebuffer_fixedinfo {

init/main.c

@@ -182,14 +182,28 @@ void kernel_init(uintptr_t arg)
 
 	printk("kernel_init() running on processor %u", this_cpu());
 
-
 	create_kernel_thread(background_thread);
 
+	struct object *fb;
 	struct object *kbd;
 
 	run_all_tests();
 
-	status = object_namespace_get_object(global_namespace(), "/dev/input/input0", &kbd);
+	status = object_get("/dev/video/fb0", &fb);
+	if (status == KERN_OK) {
+		struct device *fb_dev = cast_to_device(fb);
+		struct framebuffer_device *fb_info = FRAMEBUFFER_DEVICE(fb_dev);
+
+		printk("fb: mode=%ux%ux%u type=%u cells=%ux%u",
+		       fb_info->fb_varinfo.fb_xres, fb_info->fb_varinfo.fb_yres,
+		       fb_info->fb_varinfo.fb_flags,
+		       fb_info->fb_varinfo.fb_xcells, fb_info->fb_varinfo.fb_ycells);
+	} else {
+		printk("fb: unavailable");
+	}
+
+
+	status = object_get("/dev/input/input0", &kbd);
 	if (status != KERN_OK) {
 		printk("no keyboard available");
 		hang();

kexts/drivers/video/vesafb/extension.yaml

@@ -1,7 +1,7 @@
-name: vgafb
+name: vesafb
 description: |
-  Generic VGA driver.
-id: net.doorstuck.socks.vgafb
+  Boot-time VESA framebuffer driver.
+id: net.doorstuck.socks.vesafb
 license: BSD-3-Clause
 copyright: Copyright © Max Wash 2023
 sources:

kexts/drivers/video/vesafb/main.c

@@ -0,0 +1,65 @@
+#include <socks/printk.h>
+#include <socks/device.h>
+#include <socks/kext.h>
+#include <socks/machine/init.h>
+#include <socks/libc/stdio.h>
+
+static struct driver *vesa_driver = NULL;
+static struct framebuffer_device *vesafb = NULL;
+
+static kern_status_t set_varinfo(struct device *dev, const struct framebuffer_varinfo *info)
+{
+	return KERN_UNSUPPORTED;
+}
+
+static struct framebuffer_device_ops vesa_ops = {
+	.set_varinfo = set_varinfo,
+};
+
+static void init_vesa(struct framebuffer_device *dev)
+{
+	struct framebuffer_varinfo *varinfo = &dev->fb_varinfo;
+	struct framebuffer_fixedinfo *fixedinfo = &dev->fb_fixedinfo;
+
+	memcpy(varinfo, bootfb_varinfo(), sizeof *varinfo);
+	memcpy(fixedinfo, bootfb_fixedinfo(), sizeof *fixedinfo);
+}
+
+static kern_status_t online(struct kext *self)
+{
+	const struct framebuffer_fixedinfo *fixedinfo = bootfb_fixedinfo();
+	if (!fixedinfo->fb_baseptr) {
+		/* No VESA information avaiable, cannot create device. */
+		return KERN_OK;
+	}
+
+	vesa_driver = driver_create(self, "vesafb");
+	if (!vesa_driver) {
+		return KERN_NO_MEMORY;
+	}
+
+	driver_register(vesa_driver);
+
+	struct framebuffer_device *fb = framebuffer_device_create();
+	fb->fb_ops = &vesa_ops;
+
+	init_vesa(fb);
+
+	struct device *fb_base = framebuffer_device_base(fb);
+	snprintf(fb_base->dev_name, sizeof fb_base->dev_name, "vesafb");
+
+	kern_status_t status = device_register(fb_base, vesa_driver, misc_device());
+	if (status != KERN_OK) {
+		driver_unregister(vesa_driver);
+		driver_destroy(vesa_driver);
+		return status;
+	}
+
+	vesafb = fb;
+
+	return KERN_OK;
+}
+
+DEFINE_KEXT("net.doorstuck.socks.vesafb",
+	    online, NULL,
+	    KEXT_NO_DEPENDENCIES);

kexts/drivers/video/vga16fb/extension.yaml

@@ -1,8 +0,0 @@
-name: vga16fb
-description: |
-  Legacy VGA textmode framebuffer driver.
-id: net.doorstuck.socks.vga16fb
-license: BSD-3-Clause
-copyright: Copyright © Max Wash 2023
-sources:
-  - main.c

kexts/drivers/video/vga16fb/main.c

@@ -1,12 +0,0 @@
-#include <socks/printk.h>
-#include <socks/kext.h>
-
-static kern_status_t online(struct kext *self)
-{
-	printk("vga16fb: online");
-	return KERN_OK;
-}
-
-DEFINE_KEXT("net.doorstuck.socks.vga16fb",
-	    online, NULL,
-	    KEXT_NO_DEPENDENCIES);

kexts/drivers/video/vgafb/main.c

@@ -1,36 +0,0 @@
-#include <socks/printk.h>
-#include <socks/device.h>
-#include <socks/kext.h>
-#include <socks/libc/stdio.h>
-
-static struct driver *vga_driver = NULL;
-static struct framebuffer_device *vgafb = NULL;
-
-static kern_status_t online(struct kext *self)
-{
-	vga_driver = driver_create(self, "vgafb");
-	if (!vga_driver) {
-		return KERN_NO_MEMORY;
-	}
-
-	driver_register(vga_driver);
-
-	struct framebuffer_device *fb = framebuffer_device_create();
-	struct device *fb_base = framebuffer_device_base(fb);
-	snprintf(fb_base->dev_name, sizeof fb_base->dev_name, "vgafb");
-
-	kern_status_t status = device_register(fb_base, vga_driver, misc_device());
-	if (status != KERN_OK) {
-		driver_unregister(vga_driver);
-		driver_destroy(vga_driver);
-		return status;
-	}
-
-	vgafb = fb;
-
-	return KERN_OK;
-}
-
-DEFINE_KEXT("net.doorstuck.socks.vgafb",
-	    online, NULL,
-	    KEXT_NO_DEPENDENCIES);