From eed45cbba97aaf2cdd1d48da82ab6a2671542d37 Mon Sep 17 00:00:00 2001
From: "K. Lange" <klange@toaruos.org>
Date: Mon, 25 Jul 2022 09:51:04 +0900
Subject: [PATCH] i965: cleanup, clear screen on initial mode set

---
 base/usr/include/kernel/video.h |  2 ++
 kernel/misc/fbterm.c            | 21 ++++++++++-----------
 modules/i965.c                  | 19 ++++++++++++++++---
 3 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/base/usr/include/kernel/video.h b/base/usr/include/kernel/video.h
index 7712672a..4dd23e7e 100644
--- a/base/usr/include/kernel/video.h
+++ b/base/usr/include/kernel/video.h
@@ -20,8 +20,10 @@ extern void lfb_set_resolution(uint16_t x, uint16_t y);
 extern uint16_t lfb_resolution_x;
 extern uint16_t lfb_resolution_y;
 extern uint16_t lfb_resolution_b;
+extern uint32_t lfb_resolution_s;
 extern uint8_t * lfb_vid_memory;
 extern const char * lfb_driver_name;
 extern void (*lfb_resolution_impl)(uint16_t,uint16_t);
 extern int framebuffer_initialize(void);
+extern size_t lfb_memsize;
 #endif
diff --git a/kernel/misc/fbterm.c b/kernel/misc/fbterm.c
index 679ca247..e40c585f 100644
--- a/kernel/misc/fbterm.c
+++ b/kernel/misc/fbterm.c
@@ -15,6 +15,7 @@
 #include <kernel/string.h>
 #include <kernel/args.h>
 #include <kernel/mmu.h>
+#include <kernel/video.h>
 
 /* Whether to scroll or wrap when cursor reaches the bottom. */
 static int fbterm_scroll = 0;
@@ -29,14 +30,6 @@ static int term_state = 0;
 static char term_buf[1024] = {0};
 static int term_buf_c = 0;
 
-/* Is this in a header somewhere? */
-extern uint8_t * lfb_vid_memory;
-extern uint16_t lfb_resolution_x;
-extern uint16_t lfb_resolution_y;
-extern uint16_t lfb_resolution_b;
-extern uint32_t lfb_resolution_s;
-extern size_t lfb_memsize;
-
 /* Bitmap font details */
 #include "../../apps/terminal-font.h"
 #define char_height LARGE_FONT_CELL_HEIGHT
@@ -49,8 +42,6 @@ extern size_t lfb_memsize;
 static uint32_t fg_color = FG_COLOR;
 static uint32_t bg_color = BG_COLOR;
 
-extern uint32_t lfb_resolution_s;
-
 static inline void set_point(int x, int y, uint32_t value) {
 	if (lfb_resolution_b == 32) {
 		((uint32_t*)lfb_vid_memory)[y * (lfb_resolution_s/4) + x] = value;
@@ -132,7 +123,7 @@ static void draw_square(int x, int y) {
 	}
 }
 
-static void fbterm_draw_logo(void) {
+void fbterm_draw_logo(void) {
 	uint64_t logo_squares = 0x981818181818FFFFUL;
 	for (size_t y = 0; y < 8; ++y) {
 		for (size_t x = 0; x < 8; ++x) {
@@ -144,6 +135,14 @@ static void fbterm_draw_logo(void) {
 	}
 }
 
+void fbterm_reset(void) {
+	x = 0;
+	y = 0;
+	term_state = 0;
+	fg_color = FG_COLOR;
+	bg_color = BG_COLOR;
+}
+
 static void fbterm_init_framebuffer(void) {
 	write_char = fb_write_char;
 	get_width = fb_get_width;
diff --git a/modules/i965.c b/modules/i965.c
index 6cdb1bfd..fdb3481f 100644
--- a/modules/i965.c
+++ b/modules/i965.c
@@ -31,7 +31,6 @@
 #define REG_DSPASTRIDE    0x70188
 #define REG_DSPASURF      0x7019c
 
-extern uint32_t lfb_resolution_s;
 extern fs_node_t * lfb_device;
 static uintptr_t ctrl_regs = 0;
 
@@ -72,10 +71,13 @@ static void i965_modeset(uint16_t x, uint16_t y) {
 	lfb_resolution_y = y;
 	lfb_resolution_b = 32;
 	lfb_resolution_s = i965_mmio_read(REG_DSPASTRIDE);
-	lfb_device->length  = lfb_resolution_s * lfb_resolution_y;
-
+	lfb_memsize = lfb_resolution_s * lfb_resolution_y;
+	lfb_device->length  = lfb_memsize;
 }
 
+extern void fbterm_draw_logo(void);
+extern void fbterm_reset(void);
+
 static void setup_framebuffer(uint32_t pcidev) {
 	/* Map BAR space for the control registers */
 	uint32_t ctrl_space = pci_read_field(pcidev, PCI_BAR0, 4);
@@ -88,6 +90,17 @@ static void setup_framebuffer(uint32_t pcidev) {
 
 	lfb_resolution_impl = i965_modeset;
 	lfb_set_resolution(1440,900);
+
+	/* Normally we don't clear the screen on mode set, but we should do it here */
+	memset(lfb_vid_memory, 0, lfb_memsize);
+
+	/* Redraw the boot logo; if we were loaded by userspace, it'll probably
+	 * be overwritten pretty quickly by the compositor? But whatever... */
+	fbterm_reset();
+	fbterm_draw_logo();
+
+	/* Helpful to know why the console text got cleared */
+	dprintf("i965: video configured for %u x %u\n", lfb_resolution_x, lfb_resolution_y);
 }
 
 static void find_intel(uint32_t device, uint16_t v, uint16_t d, void * extra) {