From fde20f86f5be5a39fd3eadf95ba71761d173e0ce Mon Sep 17 00:00:00 2001 From: dzwdz Date: Thu, 24 Jun 2021 20:41:07 +0200 Subject: Hello world o/ --- kernel/tty.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 kernel/tty.c (limited to 'kernel/tty.c') diff --git a/kernel/tty.c b/kernel/tty.c new file mode 100644 index 0000000..45de728 --- /dev/null +++ b/kernel/tty.c @@ -0,0 +1,32 @@ +/* will be moved to userspace later on */ + +#include + +struct vga_cell { + unsigned char c; + unsigned char style; +} __attribute__((__packed__)); + +static const size_t vga_len = 80 * 25; +static struct vga_cell *vga = (void*) 0xB8000; +static size_t vga_pos = 0; + +static void tty_scroll() { + for (int i = 0; i < vga_len - 80; i++) { + vga[i] = vga[i + 80]; + } + vga_pos -= 80; +} + +void tty_putchar(char c) +{ + if (vga_pos >= vga_len - 80) tty_scroll(); + vga[vga_pos++].c = c; +} + +void tty_write(const char *buf, size_t len) +{ + for (size_t i = 0; i < len; i++) { + tty_putchar(buf[i]); + } +} -- cgit v1.2.3