From 457a2117706cdaee34f894e67c89da7bf29f6143 Mon Sep 17 00:00:00 2001
From: Loic Guegan <manzerbredes@mailbox.org>
Date: Mon, 12 Apr 2021 10:28:04 +0200
Subject: Refactoring

---
 src/core/framebuffer.c | 58 ----------------------------------------
 src/core/framebuffer.h | 35 ------------------------
 src/core/gdt.h         |  3 +++
 src/core/idt.c         | 39 +++++++++++++++++++++++++++
 src/core/idt.h         | 32 ++++++++++++++++++++++
 src/core/int.S         | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 146 insertions(+), 93 deletions(-)
 delete mode 100644 src/core/framebuffer.c
 delete mode 100644 src/core/framebuffer.h
 create mode 100644 src/core/idt.c
 create mode 100644 src/core/idt.h
 create mode 100644 src/core/int.S

(limited to 'src/core')

diff --git a/src/core/framebuffer.c b/src/core/framebuffer.c
deleted file mode 100644
index 110dc73..0000000
--- a/src/core/framebuffer.c
+++ /dev/null
@@ -1,58 +0,0 @@
-#include "framebuffer.h"
-
-#define MAX_COL 80
-#define MAX_LINE 25
-
-VIDEO_STATE VS={
-  (u8 *)0xB8000,
-  0,
-  0,
-  BLACK,
-  GRAY,
-};
-
-void putchar(char c){
-  // Handle newline here
-  if(c=='\n'){
-    VS.col=0;
-    VS.line+=1;
-    if(VS.line>=MAX_LINE){
-      VS.line=MAX_LINE-1;
-      scrollup();
-    }
-    return;
-  }
-  
-  // Print char
-  VS.mem[VS.col*2+MAX_COL*VS.line*2]=c;
-  VS.mem[VS.col*2+MAX_COL*VS.line*2+1]=VS.fg|VS.bg<<4;
-  
-  // Refresh location
-  VS.col+=1;
-  if(VS.col>= MAX_COL){
-    VS.col=0;
-    VS.line+=1;
-    if(VS.line>=MAX_LINE){
-      VS.line=MAX_LINE-1;
-      scrollup();
-    }
-  }
-}
-
-void clear(){
-  for(char i=0;i<MAX_LINE;i++){
-    scrollup();
-  }
-}
-
-void scrollup(){
-  // Move VS.line up
-  for(char i=1;i<=MAX_LINE;i++){
-    for(char j=0;j<=MAX_COL;j++)
-      VS.mem[j*2+MAX_COL*(i-1)*2]=VS.mem[j*2+MAX_COL*i*2];
-  }
-  // Clear last VS.line
-  for(char i=0;i<=MAX_COL;i++){
-    VS.mem[i*2+MAX_COL*(MAX_LINE-1)*2]='\0';
-  }
-}
diff --git a/src/core/framebuffer.h b/src/core/framebuffer.h
deleted file mode 100644
index 3d862d6..0000000
--- a/src/core/framebuffer.h
+++ /dev/null
@@ -1,35 +0,0 @@
-#ifndef FRAMEBUFFER_H
-#define FRAMEBUFFER_H
-
-#include "types.h"
-
-typedef enum VIDEO_COLORS {
-  BLACK=0, BLUE=1, GREEN=2,CYAN=3, RED=4,PURPLE=5,BROWN=6,GRAY=7,
-  DARK_GRAY=8,LIGHT_BLUE=9,LIGHT_GREEN=10,LIGHT_CYAN=11,LIGHT_RED=12,LIGHT_PURPLE=13,YELLOW=14,WHITE=15
-  
-} VIDEO_COLORS;
-
-typedef struct VIDEO_STATE {
-  u8 *mem;
-  u8 col;
-  u8 line;
-  u8 bg;
-  u8 fg;
-} VIDEO_STATE;
-
-/**
- * Print char
- */
-void putchar(char);
-
-/**
- * Scroll the framebuffer from one line
- */
-void scrollup();
-
-/**
- * Clear all char from the framebuffer
- */
-void clear();
-
-#endif
diff --git a/src/core/gdt.h b/src/core/gdt.h
index f010891..246ddbe 100644
--- a/src/core/gdt.h
+++ b/src/core/gdt.h
@@ -72,6 +72,9 @@ void gdt_memcpy();
  */
 void gdt_write_entry(GDT_ENTRY entry, u32 id);
 
+/**
+  * Extract the base from the user data segment 
+  */ 
 int gdt_user_ds_base();
 
 #endif
diff --git a/src/core/idt.c b/src/core/idt.c
new file mode 100644
index 0000000..4e08d62
--- /dev/null
+++ b/src/core/idt.c
@@ -0,0 +1,39 @@
+#include "idt.h"
+
+struct IDT_REGISTER IDTR={
+    8*IDT_MAX_ENTRY,
+    0x0
+};
+
+// Interrupt functions (cf int.S)
+extern u32
+INT_DEFAULT,
+INT_PAGE_FAULT,
+INT_CLOCK,
+INT_KEYPRESS,
+INT_SYSCALL;
+
+
+void idt_init(){
+    // Map first default 32 entries 
+    for(int i=0;i<IDT_MAX_ENTRY;i++){
+        idt_write_entry((IDT_ENTRY){0x08,(u32)&INT_DEFAULT,IDT_INT_GATE},i);
+        if(i==14)
+            idt_write_entry((IDT_ENTRY){0x08,(u32)&INT_PAGE_FAULT,IDT_INT_GATE},i);
+        if(i==32)
+            idt_write_entry((IDT_ENTRY){0x08,(u32)&INT_CLOCK,IDT_INT_GATE},i);
+        if(i==33)
+            idt_write_entry((IDT_ENTRY){0x08,(u32)&INT_KEYPRESS,IDT_INT_GATE},i);
+        if(i==48)
+            idt_write_entry((IDT_ENTRY){0x08,(u32)&INT_SYSCALL,IDT_TRAP_GATE},i);
+    }
+    // Load IDT
+    asm("lidtl (IDTR)");
+}
+
+void idt_write_entry(IDT_ENTRY entry, int id){
+    int descriptor[2];
+    descriptor[0]=entry.offset & 0xFFFF | entry.segment << 16;
+    descriptor[1]=entry.type & 0xFFFF | entry.offset & 0xFFFF0000;
+    memcpy((void*)descriptor, (void *)(IDTR.base+(id*8)),8);
+}
\ No newline at end of file
diff --git a/src/core/idt.h b/src/core/idt.h
new file mode 100644
index 0000000..17c5cfa
--- /dev/null
+++ b/src/core/idt.h
@@ -0,0 +1,32 @@
+#ifndef IDT_H
+#define IDT_H
+
+#include "core/types.h"
+#include "core/mem.h"
+
+#define IDT_MAX_ENTRY 200
+#define IDT_INT_GATE 0x8E00
+#define IDT_TRAP_GATE 0xEF00
+
+typedef struct IDT_ENTRY {
+    u16 segment;
+    u32 offset;
+    u16 type;
+} IDT_ENTRY;
+
+struct IDT_REGISTER {
+    u16 limit;
+    u32 base;
+} __attribute__((packed));
+
+/**
+ * Copy IDT into memory and load it
+ */
+void idt_init();
+
+/**
+ * Write an IDT entry into memory
+ */
+void idt_write_entry(IDT_ENTRY entry,int id);
+
+#endif
\ No newline at end of file
diff --git a/src/core/int.S b/src/core/int.S
new file mode 100644
index 0000000..8ca8b7a
--- /dev/null
+++ b/src/core/int.S
@@ -0,0 +1,72 @@
+.macro  SAVE_REGS
+pushal             
+push %ds
+push %es
+push %fs
+push %gs
+push %ebx
+mov $0x10,%bx
+mov %bx,%ds
+pop %ebx
+.endm
+
+.macro RESTORE_REGS
+    pop %gs
+    pop %fs
+    pop %es
+    pop %ds
+    popal
+.endm
+
+.globl interrupt_enable
+interrupt_enable:
+    call idt_init
+    call pic_init
+    sti
+    ret
+
+.globl INT_DEFAULT
+INT_DEFAULT:
+    SAVE_REGS
+    movb $0x20, %al
+    outb %al, $0x20
+    RESTORE_REGS
+    iret
+
+.globl INT_KEYPRESS
+INT_KEYPRESS:
+    SAVE_REGS
+    call _8042_keypress
+    movb $0x20, %al
+    outb %al, $0x20
+    RESTORE_REGS
+    iret
+
+.globl INT_CLOCK
+INT_CLOCK:
+    SAVE_REGS
+    call clock
+    movb $0x20, %al
+    outb %al, $0x20
+    RESTORE_REGS
+    iret
+
+.globl INT_SYSCALL
+INT_SYSCALL:
+    SAVE_REGS
+    call syscall
+    movb $0x20, %al
+    outb %al, $0x20
+    RESTORE_REGS
+    iret
+
+.globl INT_PAGE_FAULT
+INT_PAGE_FAULT:
+    SAVE_REGS
+    call page_fault
+    hlt
+    movb $0x20, %al
+    outb %al, $0x20
+    RESTORE_REGS
+    iret
+
-- 
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