fb: map as WC

kernel-src/include/kernel/term.h

@@ -2,6 +2,7 @@
 #define _TERM_H
 
 void term_init();
+void term_update_framebuffer(void *fb);
 void term_putchar(char c);
 void term_write(char *str, size_t count);
 void term_getsize(size_t *x, size_t *y, size_t *fbx, size_t *fby);

kernel-src/include/x86-64/arch/mmu.h

@@ -21,6 +21,7 @@
 #define ARCH_MMU_FLAGS_WB 0
 #define ARCH_MMU_FLAGS_WT (1 << 3)
 #define ARCH_MMU_FLAGS_UC (1 << 4)
+#define ARCH_MMU_FLAGS_WC ((1 << 12) | (1 << 3)) // PAT5 (limine sets up the 5th PAT entry as WC)
 
 #define ARCH_MMU_REQUIRED_FLAGS ARCH_MMU_FLAGS_READ
 

kernel-src/io/fb.c

@@ -7,6 +7,7 @@
 #include <arch/cpu.h>
 #include <kernel/pmm.h>
 #include <kernel/usercopy.h>
+#include <kernel/term.h>
 #include <kernel/init.h>
 
 typedef struct bitfield_t {
@@ -256,6 +257,11 @@ void fb_init() {
 
 		printf("%s: %dx%d %d bpp\n", name, fb->width, fb->height, fb->bpp);
 	}
+
+
+	void *fb_map = vmm_map(NULL, fbs[0]->pitch * fbs[0]->height, VMM_FLAGS_PHYSICAL, ARCH_MMU_FLAGS_READ | ARCH_MMU_FLAGS_WRITE | ARCH_MMU_FLAGS_NOEXEC | ARCH_MMU_FLAGS_WC, FROM_HHDM(fbs[0]->address));
+	__assert(fb_map);
+	term_update_framebuffer(fb_map);
 }
 
 INIT_ROUTINE_DEFINE(fb, INIT_ROUTINE_FLAGS_NONE, fb_init, devfs);

kernel-src/io/term.c

@@ -71,4 +71,8 @@ void term_init() {
 	logging_sethook(term_putchar);
 }
 
-INIT_ROUTINE_DEFINE(term, INIT_ROUTINE_FLAGS_NONE, term_init, pmm);
+void term_update_framebuffer(void *fb) {
+	((struct flanterm_fb_context *)fb)->framebuffer = fb;
+}
+
+INIT_ROUTINE_DEFINE(term, INIT_ROUTINE_FLAGS_NONE, term_init, vmm);