From d726c9e50a096d9f87affae5ebabfd34dae23333 Mon Sep 17 00:00:00 2001
From: Bensong Liu <bensl@microsoft.com>
Date: Mon, 2 Nov 2020 18:18:55 +0800
Subject: [PATCH] println working
---
kernel/include/stdlib.hpp | 22 +++++++++++++++++
kernel/include/vga.hpp | 52 ++++++++++++++++++++++++++++++++-------
kernel/kernel.cc | 5 ++++
3 files changed, 70 insertions(+), 9 deletions(-)
create mode 100644 kernel/include/stdlib.hpp
diff --git a/kernel/include/stdlib.hpp b/kernel/include/stdlib.hpp
new file mode 100644
index 0000000..dfeffc2
--- /dev/null
+++ b/kernel/include/stdlib.hpp
@@ -0,0 +1,22 @@
+#ifndef ROS_KERN_STDLIB_HPP
+#define ROS_KERN_STDLIB_HPP
+
+#include "stdint.hpp"
+
+template <typename T>
+inline void memcpy(T *dst, const T *src, size_t count) {
+ for(auto i = 0; i < count; ++i) {
+ dst[i] = src[i];
+ }
+}
+template <typename T>
+inline void memset(T *dst, const T &data_to_set, size_t count) {
+ char *cdst = reinterpret_cast<char *>(dst);
+
+ for(auto i = 0; i < count; ++i) {
+ cdst[i] = data_to_set;
+ }
+}
+
+
+#endif
diff --git a/kernel/include/vga.hpp b/kernel/include/vga.hpp
index b6925ed..ffebbc3 100644
--- a/kernel/include/vga.hpp
+++ b/kernel/include/vga.hpp
@@ -1,17 +1,51 @@
#ifndef ROS_KERN_VGA_HPP
#define ROS_KERN_VGA_HPP
-inline char *vga_begin = (char *)0xb8000;
-void push_char(char c, char color) {
- static int pos = 0;
- vga_begin[pos++] = c;
- vga_begin[pos++] = color;
+#include "stdint.hpp"
+#include "stdlib.hpp"
+
+#define VGA_BEGIN_ADDR ((uint16_t *)0xb8000)
+constexpr uint16_t VGA_WIDTH = 80;
+constexpr uint16_t VGA_HEIGHT = 25;
+constexpr uint16_t VGA_MAKE_CHAR(char c, uint8_t color) {
+ return (color << 8) + uint8_t(c);
+}
+constexpr uint8_t default_color = 0x0f;
+
+
+inline void trigger_scroll(uint16_t *pos) {
+ for(uint16_t row = 1; row < VGA_HEIGHT; ++row) {
+ memcpy(VGA_BEGIN_ADDR + (row-1)*VGA_WIDTH, VGA_BEGIN_ADDR + row*VGA_WIDTH, VGA_WIDTH);
+ }
+ memset(VGA_BEGIN_ADDR + (VGA_HEIGHT-1)*VGA_WIDTH, VGA_MAKE_CHAR(0, 0), VGA_WIDTH);
+ (*pos) -= VGA_WIDTH;
+}
+
+inline void set_char(uint16_t x, uint16_t y, char c, char color) {
+ VGA_BEGIN_ADDR[y*VGA_WIDTH + x] = VGA_MAKE_CHAR(c, color);
+}
+
+inline void put_char(char c, uint8_t color) {
+ static uint16_t pos = 0;
+ if(pos >= VGA_WIDTH * VGA_HEIGHT)
+ trigger_scroll(&pos);
+
+ switch(c) {
+ case '\n':
+ pos += VGA_WIDTH;
+ [[fallthrough]]; // unix \n implies \r.
+ case '\r':
+ pos -= pos % VGA_WIDTH;
+ break;
+ default:
+ VGA_BEGIN_ADDR[pos++] = VGA_MAKE_CHAR(c, color);
+ }
}
-void set_char(int x, int y, char c, char color) {
- auto pos = x + 80 * y;
- vga_begin[pos*2] = c;
- vga_begin[pos*2+1] = color;
+inline void print(const char *cstr, uint8_t color = default_color) {
+ while(*cstr != '\0') {
+ put_char(*(cstr++), color);
+ }
}
#endif
\ No newline at end of file
diff --git a/kernel/kernel.cc b/kernel/kernel.cc
index d1c4e40..5419de6 100644
--- a/kernel/kernel.cc
+++ b/kernel/kernel.cc
@@ -17,5 +17,10 @@ void main() {
set_char(x, y, c, color);
}
}
+ print("Hello world!\n");
+ print("Hello world!\n", 0xb1);
+ print("Hello world!\n", 0xae);
+ print("Hello world!\n", 0x5c);
+ print("Hello world!\n");
}
--
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