Keyboard buffer + getline

docs/MANUAL.md

@@ -2,9 +2,30 @@
 
 # Table of Contents
 
-- nothing (yet).
+- [Overview](#i-overview)
+    - [Supported Hardware](#a-supported-hardware)
+    - [Features](#b-features)
+- [Kernel architecture](#ii-kernel-architecture)
+    - [Boot process](#a-boot-process)
+    - [Memory management](#b-memory-management)
+    - [Scheduling](#c-scheduling)
+    - [Input/output](#d-inputoutput)
+- [Syscall table](#iii-syscall-table)
 
-## I. Kernel architecture
+## I. Overview
+
+## a. Supported Hardware
+
+The recommended hardware to run PepperOS is the following:
+
+- UEFI/BIOS
+- Any x86 processor, 64-bits only
+- PS/2 Keyboard
+- Minimum 128MB of memory
+
+## b. Features
+
+## II. Kernel architecture
 
 ### a. Boot process
 
@@ -14,6 +35,6 @@
 
 ### d. Input/Output
 
-## II. Syscall table
+## III. Syscall table
 
 Not yet implemented.

include/config.h

@@ -39,6 +39,9 @@
 /* term */
 #define TERM_HISTORY_MAX_LINES 256
 
+/* kbd */
+#define KBD_BUFFER_MAX 256
+
 /* time */
 #define TIMER_FREQUENCY 1000
 

include/io/kbd/ps2.h

@@ -7,7 +7,12 @@
 #ifndef PS2_H
 #define PS2_H
 
+#include <stddef.h>
+
 void keyboard_handler(void);
+char keyboard_getchar();
+int keyboard_putchar(char c);
+int keyboard_getline(char* output, size_t size);
 
 #define SHIFT_PRESSED_BIT 0b00000001
 #define ALT_PRESSED_BIT   0b00000010

src/idt/idt.c

@@ -258,7 +258,7 @@ struct cpu_status_t* interrupt_dispatch(struct cpu_status_t* context)
 
         case 33: // Keyboard Interrupt
             keyboard_handler();
-            process_create("keyboard-initiated", kbdproc_main, NULL); // DEBUG
+            //process_create("keyboard-initiated", kbdproc_main, NULL); // DEBUG
             outb(0x20, 0x20);
             break;
 

src/io/kbd/ps2.c

@@ -4,6 +4,7 @@
  * @license GPL-3.0-only
  */
 
+#include "config.h"
 #include <io/serial/serial.h>
 #include <io/kbd/ps2.h>
 #include <stdint.h>
@@ -18,6 +19,11 @@ uint8_t key_status = 0b00000000;
 unsigned char* keymap;
 unsigned char* keymap_shifted;
 
+// Keyboard buffer
+char keyboard_buffer[KBD_BUFFER_MAX] = {0};
+int write_index = 0;
+int read_index = 0;
+
 extern struct init_status init;
 
 unsigned char kbdus[128] =
@@ -214,6 +220,7 @@ void keyboard_handler()
                         }
                         // Should probably have a keyboard buffer here... instead of this
                         _putchar(c);
+                        keyboard_putchar(c);
                     }
                 }
             }
@@ -221,6 +228,79 @@ void keyboard_handler()
     }
 }
 
+/*
+ * keyboard_getchar - Get a character from keyboard
+ *
+ * This function reads one character from the keyboard buffer.
+ * If the keyboard buffer is empty, it will block until a key
+ * is pressed.
+ *
+ * Return:
+ * <char> - character from keyboard buffer
+ */
+char keyboard_getchar()
+{
+    while (read_index == write_index); // Empty buffer
+
+    char c = keyboard_buffer[read_index];
+    read_index = (read_index+1) % KBD_BUFFER_MAX;
+    return c;
+}
+
+/*
+ * keyboard_putchar - Puts a character in the keyboard buffer
+ * @c: character to add
+ *
+ * This function is used in the keyboard handler to add new
+ * characters to the keyboard buffer.
+ *
+ * Return:
+ * %-1 - keyboard buffer is full
+ * %0 - operation completed successfully
+ */
+int keyboard_putchar(char c)
+{
+    if ((write_index+1) % KBD_BUFFER_MAX == read_index) {
+        // Full buffer
+        return -1;
+   }
+   
+   keyboard_buffer[write_index] = c;
+   write_index = (write_index+1) % KBD_BUFFER_MAX;
+   return 0;
+}
+
+/*
+ * keyboard_getline - Gets a line of input from keyboard
+ * @output: Output string
+ * @size:   Size of output string
+ *
+ * Read a line of characters from the keyboard, until the
+ * buffer fills or a newline character is read.
+ * The output string is NULL-terminated.
+ *
+ * Return:
+ * <num> - the number of characters read
+ */
+int keyboard_getline(char* output, size_t size)
+{
+    char c;
+    size_t index = 0;
+    
+    // Read until Enter is pressed
+    while ((c = keyboard_getchar()) != 0x0A) {
+        if (index == size-1) {
+            output[index] = c;
+            output[index+1] = '\0';
+            return index;
+        }
+        output[index] = c;
+        index++;
+    }
+    output[index+1] = '\0';
+    return index;
+}
+
 /*
  * keyboard_init - Keyboard initialization
  * @layout: Desired layout

src/kmain.c

@@ -68,7 +68,7 @@ struct process_t* idle_proc;
 // Never gets executed although pedicel is scheduled?
 void pedicel_main(void* arg)
 {
-	printf("\n\nWelcome to PepperOS! Pedicel speaking.\r\nNothing left to do, let's go idle!");
+	printf("\n\nWelcome to PepperOS! Pedicel speaking.\r\nNothing left to do, let's go idle!\r\n");
 }
 
 void idle_main(void* arg)
@@ -78,6 +78,14 @@ void idle_main(void* arg)
 	}
 }
 
+void thing_main(void* arg)
+{
+	printf("What's your name, pal? ");
+	char name[10];
+	keyboard_getline(name, 10);
+	printf("\r\n{%s} is such a nice name!\r\n", name);
+}
+
 extern uintptr_t kheap_start;
 
 /*
@@ -118,7 +126,7 @@ void kmain()
 	process_init();
 	idle_proc = process_create("idle", (void*)idle_main, 0);
 	struct process_t* pedicel = process_create("pedicel", (void*)pedicel_main, 0);
-
+	process_create("thing", thing_main, NULL);
 	process_display_list(processes_list);
 
 	scheduler_init();

src/sched/scheduler.c

@@ -69,10 +69,10 @@ struct cpu_status_t* scheduler_schedule(struct cpu_status_t* context)
         }
     }
 
-    DEBUG("current_process={pid=%u, name='%s', root_page_table[virt]=%p}", current_process->pid, current_process->name, current_process->root_page_table);
+    //DEBUG("current_process={pid=%u, name='%s', root_page_table[virt]=%p}", current_process->pid, current_process->name, current_process->root_page_table);
 
     load_cr3(VIRT_TO_PHYS((uint64_t)current_process->root_page_table));
-    DEBUG("Loaded process PML4 into CR3");
+    //DEBUG("Loaded process PML4 into CR3");
 
     return current_process->context;
 }