Update README.md

Reviewed-on: #6

Makefile

@@ -1,6 +1,8 @@
+SOURCES = src/io/kbd/ps2.c src/io/serial/serial.c src/io/term/printf.c src/io/term/term.c src/idt/idt.c src/mem/gdt/gdt.c src/mem/misc/utils.c src/time/timer.c src/kmain.c
+
 build:
 	rm -f *.o
-	x86_64-elf-gcc -g -c -I src src/kbd/ps2.c src/time/timer.c src/idt/idt.c src/mem/utils.c src/mem/gdt.c src/io/serial.c src/io/term.c src/io/printf.c src/kmain.c -Wall -Wextra -std=gnu99 -nostdlib -ffreestanding -fno-stack-protector -fno-stack-check -fno-PIC -ffunction-sections -fdata-sections -mcmodel=kernel
+	x86_64-elf-gcc -g -c -I src $(SOURCES) -Wall -Wextra -std=gnu99 -nostdlib -ffreestanding -fno-stack-protector -fno-stack-check -fno-PIC -ffunction-sections -fdata-sections -mcmodel=kernel
 	objcopy -O elf64-x86-64 -B i386 -I binary zap-light16.psf zap-light16.o
 	nasm -f elf64 src/idt/idt.S -o idt_stub.o
 	x86_64-elf-ld -o pepperk -T linker.ld *.o

README.md

@@ -7,6 +7,25 @@ First install the dependencies: `sudo apt install xorriso make qemu-system`
 Then, to compile the kernel and make an ISO image file: `make build-iso`
 To run it with QEMU, `make run`
 
+## TODO
+
+The basics that I'm targeting are:
+
+- Fix terminal driver (backspace issues, scrolling) OR add Flanterm or equivalent
+- Implement paging / see what Limine does at boot with memory management
+- Implement tasks, and task switching
+- Load an executable
+- Scheduler (round-robin using the PIT timer interrupt)
+- Filesystem (TAR for read-only initfs, then maybe read-write using FAT12/16/32
+- Getting to userspace (syscalls)
+- Porting musl libc or equivalent
+
+In the future, maybe?
+
+- SMP support
+- Parsing the ACPI tables and using them for something
+- Replacing the PIT timer with APIC
+
 ## Thanks
 
 PepperOS wouldn't be possible without the following freely-licensed software:

src/idt/idt.c

@@ -1,8 +1,9 @@
 #include "idt.h"
 #include <stdint.h>
 #include <stddef.h>
-#include "../io/serial.h"
-#include "../kbd/ps2.h"
+#include "../io/serial/serial.h"
+#include "../io/kbd/ps2.h"
+#include <kernel.h>
 
 struct interrupt_descriptor idt[256];
 struct idtr idt_reg;
@@ -49,7 +50,7 @@ void idt_init()
         idt_set_entry(i, vector_0_handler + (i*16), 0);
     }
     idt_load(&idt);
-    serial_kputs("kernel: idt: Initialized IDT!\n");
+    DEBUG("IDT initialized");
 }
 
 struct cpu_status_t* interrupt_dispatch(struct cpu_status_t* context)
@@ -57,74 +58,74 @@ struct cpu_status_t* interrupt_dispatch(struct cpu_status_t* context)
     switch(context->vector_number)
     {
         case 0:
-            serial_kputs("kernel: idt: Divide Error!\n");
+            DEBUG("Divide Error!");
             break;
         case 1:
-            serial_kputs("kernel: idt: Debug Exception!\n");
+            DEBUG("Debug Exception!");
             break;
         case 2:
-            serial_kputs("kernel: idt: NMI Interrupt!\n");
+            DEBUG("NMI Interrupt!");
             break;
         case 3:
-            serial_kputs("kernel: idt: Breakpoint Interrupt!\n");
+            DEBUG("Breakpoint Interrupt!");
             break;
         case 4:
-            serial_kputs("kernel: idt: Overflow Trap!\n");
+            DEBUG("Overflow Trap!");
             break;
         case 5:
-            serial_kputs("kernel: idt: BOUND Range Exceeded!\n");
+            DEBUG("BOUND Range Exceeded!");
             break;
         case 6:
-            serial_kputs("kernel: idt: Invalid Opcode!\n");
+            DEBUG("Invalid Opcode!");
             break;
         case 7:
-            serial_kputs("kernel: idt: Device Not Available!\n");
+            DEBUG("Device Not Available!");
             break;
         case 8:
-            serial_kputs("kernel: idt: Double Fault!\n");
+            DEBUG("Double Fault!");
             break;
         case 9:
-            serial_kputs("kernel: idt: Coprocessor Segment Overrun!\n");
+            DEBUG("Coprocessor Segment Overrun!");
             break;
         case 10:
-            serial_kputs("kernel: idt: Invalid TSS!\n");
+            DEBUG("Invalid TSS!");
             break;
         case 11:
-            serial_kputs("kernel: idt: Segment Not Present!\n");
+            DEBUG("Segment Not Present!");
             break;
         case 12:
-            serial_kputs("kernel: idt: Stack-Segment Fault!\n");
+            DEBUG("Stack-Segment Fault!");
             break;
         case 13:
-            serial_kputs("kernel: idt: General Protection Fault!\n");
+            DEBUG("General Protection Fault!");
             break;
         case 14:
-            serial_kputs("kernel: idt: Page Fault!\n");
+            DEBUG("Page Fault!");
             break;
         case 15:
-            serial_kputs("kernel: idt: Intel Reserved Interrupt! (Achievement unlocked: How Did We Get Here?)\n");
+            DEBUG("Intel Reserved Interrupt! (Achievement unlocked: How Did We Get Here?)");
             break;
         case 16:
-            serial_kputs("kernel: idt: x87 Floating-Point Error!\n");
+            DEBUG("x87 Floating-Point Error!");
             break;
         case 17:
-            serial_kputs("kernel: idt: Alignment Check Fault!\n");
+            DEBUG("Alignment Check Fault!");
             break;
         case 18:
-            serial_kputs("kernel: idt: Machine Check!\n");
+            DEBUG("Machine Check!");
             break;
         case 19:
-            serial_kputs("kernel: idt: SIMD Floating-Point Exception!\n");
+            DEBUG("SIMD Floating-Point Exception!");
             break;
         case 20:
-            serial_kputs("kernel: idt: Virtualization Exception!\n");
+            DEBUG("Virtualization Exception!");
             break;
         case 21:
-            serial_kputs("kernel: idt: Control Protection Exception!\n");
+            DEBUG("Control Protection Exception!");
             break;
 
         case 32:
-            //serial_kputs("Tick!");
+            //DEBUG("Tick!");
             ticks++;
             // Send an EOI so that we can continue having interrupts
             outb(0x20, 0x20);
@@ -135,7 +136,7 @@ struct cpu_status_t* interrupt_dispatch(struct cpu_status_t* context)
             break;
 
         default:
-            serial_kputs("kernel: idt: Unexpected interrupt\n");
+            DEBUG("Unexpected interrupt");
             break;
     }
 

src/io/kbd/ps2.c

@@ -1,10 +1,10 @@
 // PS/2 Keyboard support
 
-#include "../io/serial.h"
-#include "../io/printf.h"
+#include "../serial/serial.h"
 #include "ps2.h"
 #include <stdint.h>
-#include "../io/term.h"
+#include "../term/term.h"
+#include <kernel.h>
 
 // The key status bitfield will be used to see if ALT, CONTROL, or SHIFT is pressed
 uint8_t key_status = 0b00000000;
@@ -206,7 +206,7 @@ void keyboard_handler()
             }
         }
 
-        serial_kputs("key pressed!\n");
+        skputs("key pressed!\n");
     }
 
     // End of Interrupt (to master PIC)
@@ -230,7 +230,8 @@ void keyboard_init(unsigned char layout)
             break;
         
         default:
-            serial_kputs("Unsupported layout.");
-            break;
+            skputs("Unsupported layout.");
+            return;
     }
+    DEBUG("PS/2 Keyboard initialized");
 }

src/io/serial/serial.c

@@ -1,4 +1,4 @@
-#include "../kernel.h"
+#include <kernel.h>
 #include "serial.h"
 
 void outb(int port, unsigned char data)
@@ -36,7 +36,7 @@ int serial_init()
     // Set normal operation mode
     outb(PORT + 4, 0x0F);
 
-    serial_kputs("\n\nkernel: serial: Serial initialization OK!\n");
+    DEBUG("serial initialized");
     return 0;
 }
 
@@ -45,18 +45,20 @@ static int is_transmit_empty()
     return inb(PORT + 5) & 0x20;
 }
 
-void write_serial(char c)
+// Serial kernel putchar
+void skputc(char c)
 {
     while (!is_transmit_empty()); // wait for free spot
     outb(PORT, c);
 }
 
-void serial_kputs(const char* str)
+// Serial kernel putstring
+void skputs(const char* str)
 {
     unsigned int i=0;
     while (str[i])
     {
-        write_serial(str[i]);
+        skputc(str[i]);
         i++;
     }
 }

src/io/serial/serial.h

@@ -5,6 +5,7 @@ void outb(int port, unsigned char data);
 unsigned char inb(int port);
 
 int serial_init();
-void serial_kputs(const char* str);
+void skputs(const char* str);
+void skputc(char c);
 
 #endif

src/io/term/term.c

@@ -2,7 +2,7 @@
 
 #include <limine.h>
 #include <stddef.h>
-#include "kernel.h"
+#include <kernel.h>
 #include "term.h"
 
 extern struct limine_framebuffer* framebuffer;
@@ -35,6 +35,7 @@ int term_init()
 	if (framebuffer)
 	{
 		fb = framebuffer->address;
+		DEBUG("terminal initialized");
 		return 0;
 	}
 	return -ENOMEM;

src/kernel.h

@@ -10,4 +10,12 @@ enum ErrorCodes
 #define CLEAR_INTERRUPTS __asm__ volatile("cli")
 #define SET_INTERRUPTS __asm__ volatile("sti")
 
+#include "io/serial/serial.h"
+#include "io/term/printf.h"
+
+// Still lacks print formatting...
+#define DEBUG(log, ...) \
+	printf("debug: [%s]: " log "\n", __FILE__, ##__VA_ARGS__); \
+	fctprintf((void*)&skputc, 0, "debug: [%s]: %s\n", __FILE__, log)
+
 #endif

src/kmain.c

@@ -1,15 +1,15 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <limine.h>
-#include "io/term.h"
-#include "io/printf.h"
-#include "io/serial.h"
-#include "mem/gdt.h"
-#include "mem/utils.h"
+#include "io/term/term.h"
+#include "io/term/printf.h"
+#include "io/serial/serial.h"
+#include "mem/gdt/gdt.h"
+#include "mem/misc/utils.h"
 #include "idt/idt.h"
 #include "kernel.h"
 #include "time/timer.h"
-#include "kbd/ps2.h"
+#include "io/kbd/ps2.h"
 
 // Limine version used
 __attribute__((used, section(".limine_requests")))
@@ -48,9 +48,8 @@ void kmain()
 	// Get the first framebuffer from the response
 	framebuffer = framebuffer_request.response->framebuffers[0];
 
-	if (term_init()) hcf();
-
-	if (serial_init()) kputs("kernel: serial: error: Cannot init serial communication!");
+	term_init();
+	serial_init();
 
 	CLEAR_INTERRUPTS;
 	gdt_init();
@@ -61,8 +60,8 @@ void kmain()
 	keyboard_init(FR);
 
 	// Draw something
-	printf("%s, %s!", "Hello", "world");
-
-	//printf("%d", 4/0);
+	printf("%s, %s!\n", "Hello", "world");
+	// Yoohoooooo!
+	DEBUG("kernel initialized successfully! hanging... wow=%d", 42);
 	hcf();
 }

src/mem/gdt/gdt.c

@@ -1,6 +1,7 @@
 #include "gdt.h"
 #include <stdint.h>
-#include "../io/serial.h"
+#include "../../io/serial/serial.h"
+#include <kernel.h>
 
 // Descriptors are 8-byte wide (64bits)
 // So the selectors will be (in bytes): 0x0, 0x8, 0x10, 0x18, etc..
@@ -78,5 +79,5 @@ void gdt_init()
     gdt_load();
     gdt_flush();
 
-    serial_kputs("kernel: gdt: Initialized GDT!\n");
+    DEBUG("GDT initialized");
 }

src/time/timer.c

@@ -1,5 +1,6 @@
 #include <stdint.h>
-#include "../io/serial.h"
+#include "../io/serial/serial.h"
+#include <kernel.h>
 
 /*
 For now, the timer module will be using the PIC.
@@ -72,4 +73,5 @@ void timer_init()
     pic_remap();
     pic_enable();
     pit_init();
+    DEBUG("PIT initialized");
 }