Basic shell

core/main.c

@@ -380,8 +380,6 @@ void kmain(unsigned long magic, unsigned long addr)
     pagingSetup(firstUsedByMem, lastUsedByMem);
     VGAMap();
 
-    printf("[Setup] IRQ handlers\n");
-    irqSetRoutineWrapped(IRQ_KEYBOARD, keyboard_do_irq);
 
     printf("[Setup] HW interrupts\n");
     // Enabling the HW interrupts
@@ -394,6 +392,10 @@ void kmain(unsigned long magic, unsigned long addr)
     printf("[Setup] allocation system\n");
     areaInit(firstUsedByMem, lastUsedByMem, _stack_bottom, _stack_top);
 
+    printf("[Setup] IRQ handlers\n");
+    keyboardSetup();
+    irqSetRoutineWrapped(IRQ_KEYBOARD, keyboard_do_irq);
+
     mmuContextSetup();
     cpu_context_subsystem_setup();
 

core/syscall.c

@@ -1,3 +1,4 @@
+#include "keyboard.h"
 #include "klibc.h"
 #include "stdarg.h"
 #include "syscall.h"
@@ -24,6 +25,9 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx){
             ret = syscallGet1arg(userCtx, &c);
             putc(c);
             break;
+        case SYSCALL_ID_READ:
+            ret = keyboardRead();
+            break;
         default:
            printf("Unknon syscall id %d\n", syscallId); 
            ret = -ENOENT;

core/syscall.h

@@ -6,6 +6,7 @@
 #define SYSCALL_ID_EXIT 1
 #define SYSCALL_ID_YOLO 2
 #define SYSCALL_ID_PUTC 3
+#define SYSCALL_ID_READ 4
 
 #ifdef __KERNEL__
 int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

drivers/keyboard.c

@@ -1,6 +1,18 @@
 #include "keyboard.h"
 #include "io.h"
 #include "klibc.h"
+#include "ringbuffer.h"
+
+#define KEYBOARD_BUFFER_SIZE 128
+
+static ringbuffer_t buf;
+
+int keyboardSetup()
+{
+    buf = ringbufferCreate(KEYBOARD_BUFFER_SIZE);
+
+    return 0;
+}
 
 const char *scancode[128] = {
     /* 0 */ 0,
@@ -308,6 +320,18 @@ void keyboard_do_irq()
         }
     }
 
-    if (key)
+    if (key){
         printf(key);
+        ringbufferEnqueue(buf, *key);
+    }
+}
+
+char keyboardRead()
+{
+    uint8_t c;
+    if (ringbufferDequeue(buf, &c)){
+        return c;
+    }
+
+    return 0;
 }

drivers/keyboard.h

@@ -6,3 +6,6 @@
 #define KEYBOARD_DATA_PORT 0x60
 
 void keyboard_do_irq();
+
+int keyboardSetup();
+char keyboardRead();

userspace/kernel/syscall.h

@@ -6,6 +6,7 @@
 #define SYSCALL_ID_EXIT 1
 #define SYSCALL_ID_YOLO 2
 #define SYSCALL_ID_PUTC 3
+#define SYSCALL_ID_READ 4
 
 #ifdef __KERNEL__
 int syscallExecute(int syscallId, const struct cpu_state *user_ctx);

userspace/libc.c

@@ -512,3 +512,38 @@ void yolo()
 {
     syscall0(SYSCALL_ID_YOLO);
 }
+
+char readc()
+{
+    return syscall0(SYSCALL_ID_READ);
+}
+
+char readcBlock()
+{
+    char c = 0;
+    do {
+        c = readc();
+    } while (c == 0);
+    return c;
+}
+
+int readline(char *buf, int size)
+{
+    int i = 0;
+    for (; i < size - 1; i++) {
+        char key = readcBlock();
+
+        if (key == '\n')
+            break;
+
+        if(key == '\b' && i>=1){
+            buf[i-1] = '\0';
+            i-=2;
+        }
+
+        buf[i] = key;
+    }
+    buf[i] = '\0';
+    return i == (size-1);
+}
+

userspace/libc.h

@@ -37,3 +37,6 @@ int syscall0(int id);
 
 void _exit(int status);
 void yolo();
+char readc();
+char readcBlock();
+int readline(char *buf, int size);

userspace/main_user.c

@@ -1,12 +1,50 @@
 #include "libc.h"
 
-int main(int argc, char *argv[])
+int func_yolo()
 {
-        (void)argc;
-        (void)argv;
         yolo();
+        return 0;
+}
+
+int func_help()
+{
+        printf("\nAvailable Commands:\n");
+        printf("        yolo\n");
+        printf("        suicide\n");
+        printf("        help\n");
+        return 0;
+}
+
+int func_suicide()
+{
         printf("User is about to suicide\n");
         int *yolo = 0;
         *yolo     = 1;
         return 0;
 }
+
+int main(int argc, char *argv[])
+{
+        (void)argc;
+        (void)argv;
+        char buf[64];
+        printf("Shell staring. type \"help\" for help\n");
+        while (1) {
+                printf(">");
+                if (readline(buf, sizeof(buf)))
+                        continue;
+                if (strcmp(buf, "yolo") == 0) {
+                        func_yolo();
+                        continue;
+                }
+                if (strcmp(buf, "help") == 0) {
+                        func_help();
+                        continue;
+                }
+                if (strcmp(buf, "suicide") == 0) {
+                        func_suicide();
+                        continue;
+                }
+        }
+        return 0;
+}