Fixed warnings

20-interrupts-timer/Makefile

@@ -7,7 +7,7 @@ OBJ = ${C_SOURCES:.c=.o cpu/interrupt.o}
 CC = /usr/local/i386elfgcc/bin/i386-elf-gcc
 GDB = /usr/local/i386elfgcc/bin/i386-elf-gdb
 # -g: Use debugging symbols in gcc
-CFLAGS = -g
+CFLAGS = -g 
 
 # First rule is run by default
 os-image.bin: boot/bootsect.bin kernel.bin

21-shell/Makefile

@@ -1 +0,0 @@
-../20-interrupts-timer/Makefile

21-shell/Makefile

@@ -0,0 +1,47 @@
+C_SOURCES = $(wildcard kernel/*.c drivers/*.c cpu/*.c libc/*.c)
+HEADERS = $(wildcard kernel/*.h drivers/*.h cpu/*.h libc/*.h)
+# Nice syntax for file extension replacement
+OBJ = ${C_SOURCES:.c=.o cpu/interrupt.o} 
+
+# Change this if your cross-compiler is somewhere else
+CC = /usr/local/i386elfgcc/bin/i386-elf-gcc
+GDB = /usr/local/i386elfgcc/bin/i386-elf-gdb
+# -g: Use debugging symbols in gcc
+CFLAGS = -g -m32 -nostdlib -nostdinc -fno-builtin -fno-stack-protector -nostartfiles -nodefaultlibs \
+		 -Wall -Wextra -Werror
+
+# First rule is run by default
+os-image.bin: boot/bootsect.bin kernel.bin
+	cat $^ > os-image.bin
+
+# '--oformat binary' deletes all symbols as a collateral, so we don't need
+# to 'strip' them manually on this case
+kernel.bin: boot/kernel_entry.o ${OBJ}
+	i386-elf-ld -o $@ -Ttext 0x1000 $^ --oformat binary
+
+# Used for debugging purposes
+kernel.elf: boot/kernel_entry.o ${OBJ}
+	i386-elf-ld -o $@ -Ttext 0x1000 $^ 
+
+run: os-image.bin
+	qemu-system-i386 -fda os-image.bin
+
+# Open the connection to qemu and load our kernel-object file with symbols
+debug: os-image.bin kernel.elf
+	qemu-system-i386 -s -fda os-image.bin -d guest_errors,int &
+	${GDB} -ex "target remote localhost:1234" -ex "symbol-file kernel.elf"
+
+# Generic rules for wildcards
+# To make an object, always compile from its .c
+%.o: %.c ${HEADERS}
+	${CC} ${CFLAGS} -ffreestanding -c $< -o $@
+
+%.o: %.asm
+	nasm $< -f elf -o $@
+
+%.bin: %.asm
+	nasm $< -f bin -o $@
+
+clean:
+	rm -rf *.bin *.dis *.o os-image.bin *.elf
+	rm -rf kernel/*.o boot/*.bin drivers/*.o boot/*.o cpu/*.o

21-shell/README.md

@@ -31,6 +31,12 @@ move `drivers/ports.*` into `cpu/` since it is clearly cpu-dependent code.
 `boot/` is also CPU-dependent code, but we will not mess with it until
 we implement the boot sequence for a different machine.
 
+There are more switches for the `CFLAGS` on the `Makefile`, since we will now
+start creating higher-level functions for our C library and we don't want
+the compiler to include any external code if we make a mistake with a declaration.
+We also added some flags to turn warnings into errors, since an apparantly minor mistake
+converting pointers can blow up later on. This also forced us to modify some misc pointer
+declarations in our code.
 
 Keyboard characters
 -------------------

21-shell/cpu/isr.c

@@ -1,7 +1,9 @@
 #include "isr.h"
 #include "idt.h"
 #include "../drivers/screen.h"
+#include "../drivers/keyboard.h"
 #include "../libc/string.h"
+#include "timer.h"
 #include "ports.h"
 
 isr_t interrupt_handlers[256];

21-shell/cpu/isr.h

@@ -81,6 +81,7 @@ typedef struct {
 
 void isr_install();
 void isr_handler(registers_t r);
+void irq_install();
 
 typedef void (*isr_t)(registers_t);
 void register_interrupt_handler(u8 n, isr_t handler);

21-shell/cpu/timer.c

@@ -1,9 +1,10 @@
 #include "timer.h"
 #include "isr.h"
+#include "ports.h"
 
 u32 tick = 0;
 
-static void timer_callback(registers_t regs) {
+static void timer_callback() {
     tick++;
 }
 

21-shell/drivers/keyboard.c

@@ -8,6 +8,8 @@
 #define BACKSPACE 0x0E
 #define ENTER 0x1C
 
+static char key_buffer[256];
+
 #define SC_MAX 57
 const char *sc_name[] = { "ERROR", "Esc", "1", "2", "3", "4", "5", "6", 
     "7", "8", "9", "0", "-", "=", "Backspace", "Tab", "Q", "W", "E", 
@@ -21,7 +23,7 @@ const char sc_ascii[] = { '?', '?', '1', '2', '3', '4', '5', '6',
         'H', 'J', 'K', 'L', ';', '\'', '`', '?', '\\', 'Z', 'X', 'C', 'V', 
         'B', 'N', 'M', ',', '.', '/', '?', '?', '?', ' '};
 
-static void keyboard_callback(registers_t regs) {
+static void keyboard_callback() {
     /* The PIC leaves us the scancode in port 0x60 */
     u8 scancode = port_byte_in(0x60);
     

21-shell/drivers/keyboard.h

@@ -1,5 +1,3 @@
 #include "../cpu/types.h"
 
-static char key_buffer[256];
-
 void init_keyboard();

21-shell/drivers/screen.c

@@ -1,5 +1,6 @@
 #include "screen.h"
 #include "../cpu/ports.h"
+#include "../libc/mem.h"
 
 /* Declaration of private functions */
 int get_cursor_offset();
@@ -64,7 +65,7 @@ void kprint_backspace() {
  * Sets the video cursor to the returned offset
  */
 int print_char(char c, int col, int row, char attr) {
-    unsigned char *vidmem = (unsigned char*) VIDEO_ADDRESS;
+    u8 *vidmem = (u8*) VIDEO_ADDRESS;
     if (!attr) attr = WHITE_ON_BLACK;
 
     /* Error control: print a red 'E' if the coords aren't right */
@@ -94,12 +95,12 @@ int print_char(char c, int col, int row, char attr) {
     if (offset >= MAX_ROWS * MAX_COLS * 2) {
         int i;
         for (i = 1; i < MAX_ROWS; i++) 
-            memory_copy(get_offset(0, i) + VIDEO_ADDRESS,
-                        get_offset(0, i-1) + VIDEO_ADDRESS,
+            memory_copy((u8*)(get_offset(0, i) + VIDEO_ADDRESS),
+                        (u8*)(get_offset(0, i-1) + VIDEO_ADDRESS),
                         MAX_COLS * 2);
 
         /* Blank last line */
-        char *last_line = get_offset(0, MAX_ROWS-1) + VIDEO_ADDRESS;
+        char *last_line = (char*) (get_offset(0, MAX_ROWS-1) + (u8*) VIDEO_ADDRESS);
         for (i = 0; i < MAX_COLS * 2; i++) last_line[i] = 0;
 
         offset -= 2 * MAX_COLS;
@@ -125,15 +126,15 @@ void set_cursor_offset(int offset) {
     /* Similar to get_cursor_offset, but instead of reading we write data */
     offset /= 2;
     port_byte_out(REG_SCREEN_CTRL, 14);
-    port_byte_out(REG_SCREEN_DATA, (unsigned char)(offset >> 8));
+    port_byte_out(REG_SCREEN_DATA, (u8)(offset >> 8));
     port_byte_out(REG_SCREEN_CTRL, 15);
-    port_byte_out(REG_SCREEN_DATA, (unsigned char)(offset & 0xff));
+    port_byte_out(REG_SCREEN_DATA, (u8)(offset & 0xff));
 }
 
 void clear_screen() {
     int screen_size = MAX_COLS * MAX_ROWS;
     int i;
-    char *screen = VIDEO_ADDRESS;
+    u8 *screen = (u8*) VIDEO_ADDRESS;
 
     for (i = 0; i < screen_size; i++) {
         screen[i*2] = ' ';

21-shell/drivers/screen.h

@@ -1,6 +1,8 @@
 #ifndef SCREEN_H
 #define SCREEN_H
 
+#include "../cpu/types.h"
+
 #define VIDEO_ADDRESS 0xb8000
 #define MAX_ROWS 25
 #define MAX_COLS 80

21-shell/libc/mem.c

@@ -1,6 +1,6 @@
 #include "mem.h"
 
-void memory_copy(char *source, char *dest, int nbytes) {
+void memory_copy(u8 *source, u8 *dest, int nbytes) {
     int i;
     for (i = 0; i < nbytes; i++) {
         *(dest + i) = *(source + i);

21-shell/libc/mem.h

@@ -3,7 +3,7 @@
 
 #include "../cpu/types.h"
 
-void memory_copy(char *source, char *dest, int nbytes);
+void memory_copy(u8 *source, u8 *dest, int nbytes);
 void memory_set(u8 *dest, u8 val, u32 len);
 
 #endif

21-shell/libc/string.h

@@ -4,6 +4,7 @@
 void int_to_ascii(int n, char str[]);
 void reverse(char s[]);
 int strlen(char s[]);
+void backspace(char s[]);
 void append(char s[], char n);
 int strcmp(char s1[], char s2[]);