feat: io: serial & console

kernel/src/kmain.c

@@ -1,7 +1,9 @@
 #include "../../common/bootinfo.h"
+#include "console.h"
 #include "types.h"
 
 #include "shitgui.h"
+#include "serial.h"
 
 void kmain(Bootinfo* info) {
     u32 *fb = (u32*)info->base;
@@ -29,5 +31,11 @@ void kmain(Bootinfo* info) {
     p.y += stripe_h;
     sg_draw_rect(&sg_ctx, &p, info->width, stripe_h, 0x5BCEFA);
 
+    serial_init();
+    console_init(&sg_ctx);
+    console_set_color(0x000000);
+    kprint("Hello!!!");
+    for (int i = 0; i < 1000; i++) kprint("!");
+
     while (1) { __asm__("hlt"); }
 }

kernel/src/modules/console.c

@@ -0,0 +1,44 @@
+#include "console.h"
+#include "serial.h"
+#include "font.h"
+#include "shitgui.h"
+
+static SG_Context *ctx_ptr = nullptr;
+static SG_Point s_cursor_pos = {0};
+static SG_Font s_font = {0};
+static u32 s_color = 0xFFFFFF;
+
+void console_init(SG_Context *ctx) {
+    ctx_ptr = ctx;
+    s_cursor_pos.x = 0;
+    s_cursor_pos.y = 0;
+
+    s_font.h = 8;
+    s_font.w = 8;
+    s_font.base = (const unsigned char*)font8x8_basic;
+}
+
+static void console_putc(char c) {
+    serial_writec(c);
+    if (!ctx_ptr) return;
+    if (c == '\n') {
+        s_cursor_pos.x = 0;
+        s_cursor_pos.y += s_font.h;
+    } else {
+        sg_draw_char_bitmap(ctx_ptr, &s_cursor_pos, c, s_color, &s_font);
+        s_cursor_pos.x += s_font.w;
+    }
+
+    if (s_cursor_pos.x >= ctx_ptr->width) {
+        s_cursor_pos.x = 0;
+        s_cursor_pos.y += s_font.h;
+    }
+}
+
+void console_set_color(u32 color) {
+    s_color = color;
+}
+
+void kprint(const char *str) {
+    for (int i = 0; str[i] != '\0'; i++) console_putc(str[i]);
+}

kernel/src/modules/memory.c

@@ -1,3 +1,4 @@
+#include "memory.h"
 #include "types.h"
 
 void *memset(void *ptr, int value, usize num) {

kernel/src/modules/serial.c

@@ -0,0 +1,28 @@
+#include "serial.h"
+#include "io.h"
+
+#define PORT 0x3F8 // com1
+
+int serial_init() {
+    outb(PORT + 1, 0x00); // interrupt enable register (+1) / disable interruptions
+    outb(PORT + 3, 0x80); // line control register (+3) 
+    outb(PORT + 0, 0x03); // speed : low byte
+    outb(PORT + 1, 0x00); // speed : high byte
+    outb(PORT + 3, 0x03); // line control register (+3) / reset DLAB / no parity / 1 stop bit / (8N1)
+    outb(PORT + 2, 0xC7); // FIFO Control register (+2) / 1100 0111 / last ones are enable FIFO buff / first ones to clean noise
+    outb(PORT + 4, 0x0B); // ready :3
+    return 0;
+}
+
+static int is_transmit_empty() { 
+    return inb(PORT + 5) & 0x20; // checking 5th bit LSR 
+}
+
+void serial_writec(char chr) {
+    while (is_transmit_empty() == 0); // waiting for buffer to flush (spinlock)
+    outb(PORT, chr);
+}
+
+void serial_write(const char *str) {
+    for (int i = 0; str[i] != '\0'; i++) serial_writec(str[i]);
+}

kernel/src/modules/shitgui.c

@@ -42,4 +42,27 @@ void sg_draw_rect(SG_Context *ctx, SG_Point *p, u32 w, u32 h, u32 color) {
         volatile u32 *row_ptr = &ctx->fb[(start_y + y) * ctx->pitch + start_x];
         for (u32 x = 0; x < draw_w; x++) row_ptr[x] = color;
     }
+}
+
+void sg_draw_char_bitmap(SG_Context *ctx, SG_Point *p, char c, u32 color, SG_Font *font) {
+    if (!ctx->fb) return;
+
+    u32 start_x = p->x;
+    u32 start_y = p->y;
+    u32 draw_w = font->w;
+    u32 draw_h = font->h;
+
+    if (start_x >= ctx->width || start_y >= ctx->height) return;
+    if (start_x + draw_w > ctx->width) draw_w = ctx->width - start_x;
+    if (start_y + draw_h > ctx->height) draw_h = ctx->height - start_y;
+
+    for (u32 y = 0; y < draw_h; y++) {
+        u8 bitmap_row = font->base[(unsigned char)c * font->h + y];
+        volatile u32 *row_ptr = &ctx->fb[(start_y + y) * ctx->pitch + start_x];
+        for (u32 x = 0; x < draw_w; x++) {
+            if (bitmap_row & (1 << (font->w - 1 - x))) {
+                row_ptr[x] = color;
+            }
+        }
+    }
 }