summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorDanny Holman <dholman@gymli.xyz>2021-01-17 20:16:00 -0600
committerDanny Holman <dholman@gymli.xyz>2021-01-17 20:16:00 -0600
commit5064ec05b2af9e17aa1753575bef457a284ad61d (patch)
treeac65aaba0d21ce59e848eebc7befa3b72a7a92a0 /arch
parent50bc91ab29672a2a99cd97c0d560d1ccc69f1cf6 (diff)
arch: i386: add support for x86 processors
Add support for 32-bit x86 processors, i.e. the 80386 and above. Signed-off-by: Danny Holman <dholman@gymli.xyz>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/boot.s32
-rw-r--r--arch/i386/crti.s15
-rw-r--r--arch/i386/crtn.s7
-rw-r--r--arch/i386/tty.c55
-rw-r--r--arch/i386/vga.h33
5 files changed, 142 insertions, 0 deletions
diff --git a/arch/i386/boot.s b/arch/i386/boot.s
new file mode 100644
index 0000000..56ac227
--- /dev/null
+++ b/arch/i386/boot.s
@@ -0,0 +1,32 @@
+.set ALIGN, 1<<0
+.set MEMINFO, 1<<1
+.set FLAGS, ALIGN | MEMINFO
+.set MAGIC, 0x1BADB002
+.set CHECKSUM, -(MAGIC + FLAGS)
+
+.section .multiboot
+.align 4
+.long MAGIC
+.long FLAGS
+.long CHECKSUM
+
+.section .bss
+.align 16
+stack_bottom:
+.skip 16384
+stack_top:
+
+.section .text
+.global _start
+.type _start, @function
+
+_start:
+ movl $stack_top, %esp
+
+ call _init
+ call kernel_main
+
+ cli
+1: hlt
+ jmp 1b
+.size _start, . - _start
diff --git a/arch/i386/crti.s b/arch/i386/crti.s
new file mode 100644
index 0000000..4e1e4cb
--- /dev/null
+++ b/arch/i386/crti.s
@@ -0,0 +1,15 @@
+.section .init
+.global _init
+.type _init, @function
+
+_init:
+ pushl %ebp
+ movl %esp, %ebp
+
+.section .fini
+.global _fini
+.type _fini, @function
+
+_fini:
+ pushl %ebp
+ movl %esp, %ebp
diff --git a/arch/i386/crtn.s b/arch/i386/crtn.s
new file mode 100644
index 0000000..447afb1
--- /dev/null
+++ b/arch/i386/crtn.s
@@ -0,0 +1,7 @@
+.section .init
+ popl %ebp
+ ret
+
+.section .fini
+ popl %ebp
+ ret
diff --git a/arch/i386/tty.c b/arch/i386/tty.c
new file mode 100644
index 0000000..9c3985b
--- /dev/null
+++ b/arch/i386/tty.c
@@ -0,0 +1,55 @@
+#include "vga.h"
+#include <kernel/tty.h>
+#include <kernel/string.h>
+#include <stddef.h>
+#include <stdint.h>
+
+static const size_t VGA_WIDTH = 80;
+static const size_t VGA_HEIGHT = 25;
+static uint16_t *const VGA_MEMORY = (uint16_t*)0xB8000;
+
+static size_t terminal_row;
+static size_t terminal_column;
+static uint8_t terminal_color;
+static uint16_t *terminal_buffer;
+
+void tty_init(void) {
+ terminal_row = 0;
+ terminal_column = 0;
+ terminal_color = vga_entry_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
+ terminal_buffer = VGA_MEMORY;
+ for (size_t y = 0; y < VGA_HEIGHT; y++) {
+ for (size_t x = 0; x < VGA_WIDTH; x++) {
+ const size_t index = y * VGA_WIDTH + x;
+ terminal_buffer[index] = vga_entry(' ', terminal_color);
+ }
+ }
+}
+
+void tty_setcolor(uint8_t color) {
+ terminal_color = color;
+}
+
+void tty_putentryat(unsigned char c, uint8_t color, size_t x, size_t y) {
+ const size_t index = y * VGA_WIDTH + x;
+ terminal_buffer[index] = vga_entry(c, color);
+}
+
+void tty_putchar(char c) {
+ unsigned char uc = c;
+ tty_putentryat(uc, terminal_color, terminal_column, terminal_row);
+ if (++terminal_column == VGA_WIDTH) {
+ terminal_column = 0;
+ if (++terminal_row == VGA_HEIGHT)
+ terminal_row = 0;
+ }
+}
+
+void tty_write(const char *data, size_t size) {
+ for (size_t i = 0; i < size; i++)
+ tty_putchar(data[i]);
+}
+
+void tty_writestring(const char *data) {
+ tty_write(data, strlen(data));
+}
diff --git a/arch/i386/vga.h b/arch/i386/vga.h
new file mode 100644
index 0000000..e89f202
--- /dev/null
+++ b/arch/i386/vga.h
@@ -0,0 +1,33 @@
+#ifndef I386_VGA_H
+#define I386_VGA_H
+
+#include <stdint.h>
+
+enum vga_color {
+ VGA_COLOR_BLACK = 0,
+ VGA_COLOR_BLUE = 1,
+ VGA_COLOR_GREEN = 2,
+ VGA_COLOR_CYAN = 3,
+ VGA_COLOR_RED = 4,
+ VGA_COLOR_MAGENTA = 5,
+ VGA_COLOR_BROWN = 6,
+ VGA_COLOR_LIGHT_GREY = 7,
+ VGA_COLOR_DARK_GREY = 8,
+ VGA_COLOR_LIGHT_BLUE = 9,
+ VGA_COLOR_LIGHT_GREEN = 10,
+ VGA_COLOR_LIGHT_CYAN = 11,
+ VGA_COLOR_LIGHT_RED = 12,
+ VGA_COLOR_LIGHT_MAGENTA = 13,
+ VGA_COLOR_LIGHT_BROWN = 14,
+ VGA_COLOR_LIGHT_WHITE = 15,
+};
+
+static inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) {
+ return fg | bg << 4;
+}
+
+static inline uint16_t vga_entry(unsigned char uc, uint8_t color) {
+ return (uint16_t)uc | (uint16_t)color << 8;
+}
+
+#endif