.gitignore

@@ -5,3 +5,4 @@ blankos.iso
 iso/
 i386-elf-7.5.0-Linux-x86_64/
 i386-elf-7.5.0-Linux-x86_64.tar.xz
+src/initrd/*.bin

docs/DEVELOPERS.md

@@ -42,6 +42,8 @@ sudo qemu-system-i386 -drive if=pflash,format=raw,readonly=on,file=/usr/share/OV
 
 Be warned, these are not actual programs in the sense you'd expect. These are indeed functions that are called from the shell, and embedded in the kernel ELF binary. Real programs apart from the kernel are not yet a thing here, but might be one day.
 
+(Now, there is a 'beginning' of something that we could call real programs, but I still suck at making the syscalls work. One day, one day...)
+
 ### Step 1 - Making the program and the entry point
 
 To make a program for the OS, first create the appropriate C source file and header file in the `src/programs` subfolder. Name it appropriately, for example `myprogram.c`.

docs/USERS.md

@@ -143,3 +143,7 @@ Starts a simplified and buggy snake game. You can choose the speed by setting th
 Controls:
 - `q` to quit
 - `wasd` to move
+
+#### `exec <binary>`
+
+Executes a binary file. Warning: this is highly broken and syscalls aren't working. It's written in a childish manner. Help is always appreciated (lol).

makefile

@@ -1,22 +1,27 @@
 CC = i386-elf-7.5.0-Linux-x86_64/bin/i386-elf-gcc
-CFLAGS = -ffreestanding -g -Wall -Wextra -Wno-builtin-declaration-mismatch -mno-sse -mno-mmx -mno-avx -march=i386 -c -I src/
+CFLAGS = -ffreestanding -g -Wall -Wextra -mno-sse -mno-mmx -mno-avx -march=i386 -c -I src/
+LD = ld
 LDFLAGS = -T link.ld -melf_i386
 AS = nasm
 ASFLAGS = -f elf
+AR = i386-elf-7.5.0-Linux-x86_64/bin/i386-elf-ar
 
 SRC_DIR = src
 KERNEL_DIR = $(SRC_DIR)/kernel
 LIBC_DIR = $(SRC_DIR)/libc
-PROGRAMS_DIR = $(SRC_DIR)/programs
+UTILS_DIR = $(SRC_DIR)/utils
 DRIVERS_DIR = $(SRC_DIR)/drivers
+PROGRAMS_DIR = $(SRC_DIR)/programs
 INCLUDE_DIR = include
 FONTS_DIR = $(INCLUDE_DIR)/fonts
 OBJ_DIR = build
 
-C_SOURCES = $(wildcard $(KERNEL_DIR)/*.c) $(wildcard $(LIBC_DIR)/*.c) $(wildcard $(PROGRAMS_DIR)/*.c) $(wildcard $(DRIVERS_DIR)/*.c)
-ASM_SOURCES = $(wildcard $(KERNEL_DIR)/*.s) $(wildcard $(LIBC_DIR)/*.s) $(wildcard $(PROGRAMS_DIR)/*.s) $(wildcard $(DRIVERS_DIR)/*.s)
+C_SOURCES = $(wildcard $(KERNEL_DIR)/*.c) $(wildcard $(LIBC_DIR)/*.c) $(wildcard $(UTILS_DIR)/*.c) $(wildcard $(DRIVERS_DIR)/*.c)
+ASM_SOURCES = $(wildcard $(KERNEL_DIR)/*.s) $(wildcard $(LIBC_DIR)/*.s) $(wildcard $(UTILS_DIR)/*.s) $(wildcard $(DRIVERS_DIR)/*.s)
+PROGRAM_SOURCES = $(wildcard $(PROGRAMS_DIR)/*.c)
 
 OBJECTS = $(patsubst $(SRC_DIR)/%, $(OBJ_DIR)/%, $(C_SOURCES:.c=.o) $(ASM_SOURCES:.s=.o)) 
+PROGRAM_OBJECTS = $(patsubst $(SRC_DIR)/%, $(OBJ_DIR)/%, $(PROGRAM_SOURCES:.c=.o))
 
 TOOLCHAIN_SRC = https://newos.org/toolchains/i386-elf-7.5.0-Linux-x86_64.tar.xz
 TOOLCHAIN_FILE = i386-elf-7.5.0-Linux-x86_64.tar.xz
@@ -24,14 +29,21 @@ TOOLCHAIN_FILE = i386-elf-7.5.0-Linux-x86_64.tar.xz
 FONT_OBJ = $(OBJ_DIR)/fonts/UniCyr_8x16.o
 FONT_SRC = $(FONTS_DIR)/UniCyr_8x16.psf
 
-all: $(OBJ_DIR) kernel.elf
+all: $(OBJ_DIR) kernel.elf programs
 
 $(OBJ_DIR):
 	mkdir -p $(OBJ_DIR)
-	mkdir -p $(OBJ_DIR)/kernel $(OBJ_DIR)/libc $(OBJ_DIR)/programs $(OBJ_DIR)/drivers $(OBJ_DIR)/fonts
-
+	mkdir -p $(OBJ_DIR)/kernel $(OBJ_DIR)/libc $(OBJ_DIR)/utils $(OBJ_DIR)/drivers $(OBJ_DIR)/fonts $(OBJ_DIR)/programs
+	
 kernel.elf: $(OBJECTS) $(FONT_OBJ)
-	ld $(LDFLAGS) $(OBJECTS) $(FONT_OBJ) -o kernel.elf
+	$(LD) $(LDFLAGS) $(OBJECTS) $(FONT_OBJ) -o kernel.elf
+
+programs: $(PROGRAM_OBJECTS)
+	@mkdir -p $(SRC_DIR)/initrd
+	@for prog in $(PROGRAM_OBJECTS); do \
+		base=$$(basename $$prog .o); \
+		$(LD) -melf_i386 -T program.ld $$prog -o $(SRC_DIR)/initrd/$$base.bin; \
+	done
 
 $(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
 	$(CC) $(CFLAGS) $< -o $@
@@ -66,5 +78,5 @@ debug:
 	./debug.sh
 
 clean:
-	rm -rf $(OBJ_DIR) kernel.elf blankos.iso $(TOOLCHAIN_FILE)
+	rm -rf $(OBJ_DIR) kernel.elf blankos.iso $(TOOLCHAIN_FILE) $(SRC_DIR)/initrd/*.bin
 

program.ld

@@ -0,0 +1,10 @@
+OUTPUT_FORMAT(binary)
+ENTRY(main)
+
+SECTIONS
+{
+	. = 0x1000;
+	.text : { *(.text*) }
+	.data : { *(.data*) }
+	.bss : { *(.bss*) }
+}

src/kernel/initrd.c

@@ -8,6 +8,7 @@
 #include "../libc/string.h"
 #include "initrd.h"
 #include "system.h"
+#include "kheap.h"
 
 static unsigned int octal_to_int(const char* str, size_t size)
 {
@@ -31,6 +32,18 @@ uint32_t tar_parse_size(const char* in)
 	return size;
 }
 
+uint32_t tar_get_size(tar_header_t* header)
+{
+	uint32_t size = 0;
+	char* size_str = header->size;
+
+	for (int i=0; i<11 && size_str[i] != '\0'; i++)
+	{
+		size = size*8 + (size_str[i]-'0');
+	}
+	return size;
+}
+
 void tar_find_file(uint8_t *tar_start, const char* filename)
 {
 	uint8_t *ptr = tar_start;
@@ -174,3 +187,52 @@ uint32_t tar_get_file_size(uint8_t* initrd, const char* filename)
 	}
 	return -1;
 }
+
+tar_header_t* tar_find(uint8_t* initrd, const char* filename)
+{
+	tar_header_t* header = (tar_header_t*)initrd;
+	while (header->filename[0] != '\0')
+	{
+		if (strcmp(header->filename, filename) == 0)
+		{
+			return header;
+		}
+
+		uint32_t file_size = tar_get_size(header);
+		uint32_t file_blocks = (file_size + 511)/512;
+		header = (tar_header_t*) ((uintptr_t)header+(file_blocks+1)*512);
+	}
+
+	return NULL;
+}
+
+void* tar_get_file_content(tar_header_t* header)
+{
+	return (void*) ((uintptr_t)header+512);
+}
+
+void* load_file_from_initrd(uint8_t* initrd, const char* filename)
+{
+	tar_header_t* file = tar_find(initrd, filename);
+	if (file == NULL)
+	{
+		printf("'%s' not found\n", filename);
+		return NULL;
+	}
+
+	uint32_t file_size = tar_get_size(file);
+
+	void* file_data = malloc(file_size);
+	if (file_data == NULL)
+	{
+		printf("Malloc error for file '%s'\n", filename);
+		return NULL;
+	}
+
+	void* file_content = tar_get_file_content(file);
+	memcpy(file_data, file_content, file_size);
+
+	printf("[initrd] Loaded '%s' at 0x%x, size=%u\n", filename, (unsigned int)file_data, file_size);
+
+	return file_data;
+}

src/kernel/initrd.h

@@ -35,5 +35,6 @@ void ls_initrd(uint8_t* initrd, int verbose);
 void cat_initrd(uint8_t* initrd, const char* filename);
 int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer);
 uint32_t tar_get_file_size(uint8_t* initrd, const char* filename);
+void* load_file_from_initrd(uint8_t* initrd, const char* filename);
 
 #endif

src/kernel/irq.c

@@ -25,6 +25,8 @@ extern void irq13();
 extern void irq14();
 extern void irq15();
 
+extern void syscall_common_stub();
+
 void *irq_routines[16] =
 {
 	0, 0, 0, 0, 0, 0, 0, 0,
@@ -76,6 +78,8 @@ void irq_install()
 	idt_set_gate(46, (unsigned)irq14, 0x08, 0x8E);
 	idt_set_gate(47, (unsigned)irq15, 0x08, 0x8E);
 	printf("[kernel] installed irq 0-15\n");
+
+	idt_set_gate(0x80, (unsigned long)syscall_common_stub, 0x08, 0x8E);
 }
 
 void irq_handler(struct regs *r)

src/kernel/kheap.c

@@ -6,6 +6,7 @@
 #include "kheap.h"
 #include <stdint.h>
 #include "system.h"
+#include "../libc/stdio.h"
 
 // Free list allocator
 
@@ -17,6 +18,7 @@ void init_alloc()
 	free_list = (block_t*)heap;
 	free_list->size = HEAP_SIZE-sizeof(block_t);
 	free_list->next = NULL;
+	printf("[kernel] initialized heap and allocator, start=0x%x\n", heap);
 }
 
 void* malloc(size_t size)

src/kernel/kheap.h

@@ -17,7 +17,6 @@ typedef struct block
 
 #define HEAP_SIZE 1024*1024	// 1MB malloc-able
 
-
 void init_alloc();
 void* malloc(size_t size);
 void free(void* ptr);

src/kernel/kmain.c

@@ -15,7 +15,7 @@
 #include "multiboot2.h"
 #include "kheap.h"
 #include "initrd.h"
-#include "../programs/programs.h"
+#include "../utils/utils.h"
 #include "../libc/crypto.h"
 
 void kmain(multiboot2_info *mb_info)
@@ -78,14 +78,14 @@ void kmain(multiboot2_info *mb_info)
 		
 		if (mmap->addr != 0)
 		{
-			
+			/*
 			serial_printf(3, "base addr=0x%x%x, length=0x%x%x, type=%u",
 				(uint32_t) (mmap->addr >> 32),
 				(uint32_t) (mmap->addr & 0xFFFFFFFF),
 				(uint32_t) (mmap->len >> 32),
 				(uint32_t) (mmap->len & 0xFFFFFFFF),
 				mmap->type);
-			
+			*/
 		}
 
 		mmap = (struct multiboot_mmap_entry*) ((uint8_t*)mmap + mmap_tag->entry_size);
@@ -118,6 +118,8 @@ void kmain(multiboot2_info *mb_info)
     printf("[debug] malloc test ptr1=0x%x, ptr2=0x%x\n", (unsigned int)ptr1, (unsigned int)ptr2); 
     free(ptr1); free(ptr2);
 
+    // usually the place where i do testing
+
     timer_install();
     keyboard_install();
     printf("[kernel] spawning shell...\n"); 

src/kernel/loader.s

@@ -210,8 +210,39 @@ irq_common_stub:
 	add esp, 8
 	iret
 
+; we'll be placing the syscall_common_stub here.
+; push everything, then call syscall_handler (be sure to define it extern)
+; then pop back everything and iret
+extern syscall_handler
+
+global syscall_common_stub
+syscall_common_stub:
+	pusha
+	push ds
+	push es
+	push fs
+	push gs
+	
+	mov eax, ds
+	push eax	; save ds
+	mov ax, 0x01	; kernel segment YES I CHEATED I KNOW THIS SUCKS
+	mov ds, ax
+	mov es, ax
+	
+	call syscall_handler
+
+	pop eax
+	mov ds, eax	; restore ds
+
+	pop gs
+	pop fs
+	pop es
+	pop ds
+	popa
+	iret
+
 section .bss
 align 4 
 
-resb KERNEL_STACK_SIZE
 kernel_stack:
+	resb KERNEL_STACK_SIZE

src/kernel/shell.c

@@ -6,7 +6,7 @@
 #include "system.h"
 #include "../libc/stdio.h"
 #include "../libc/string.h"
-#include "../programs/programs.h"
+#include "../utils/utils.h"
 #include "../libc/crypto.h"
 #include <stdint.h>
 #include "../drivers/rtc.h"
@@ -146,6 +146,7 @@ void shell_install()
   register_command("lspci", program_lspci);
   register_command("naval", program_navalbattle);
   register_command("snake", program_snake);
+  register_command("exec", program_exec);
 
   for (;;)
   {

src/kernel/syscalls.c

@@ -0,0 +1,33 @@
+// System calls
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+#include "../libc/stdio.h"
+
+void handle_syscall(int syscall_number)
+{
+	switch(syscall_number)
+	{
+		case 1:
+			puts("Here's the syscall 1\n");
+			break;
+		default:
+			printf("[error] Invalid syscall number '%d'!\n", syscall_number);
+			break;
+	}
+}
+
+void syscall_handler()
+{
+	int syscall_number;
+	void* arg;
+	// mov eax, syscall_number
+	// mov ebx, arg
+	asm volatile("mov %%eax, %0" : "=r"(syscall_number));
+	asm volatile("mov %%ebx, %0" : "=r"(arg));
+
+	printf("[syscall] syscall_number=%d, arg=%p\n", syscall_number, arg);
+
+	handle_syscall(syscall_number);
+}

src/kernel/system.h

@@ -39,5 +39,7 @@ extern volatile unsigned long global_ticks;
 
 extern unsigned int g_multiboot_info_address;
 
+void syscall_handler();
+
 #endif
 

src/programs/hello.c

@@ -0,0 +1,10 @@
+void user_syscall(int syscall_no) {
+	asm volatile ("mov %0, %%eax" : : "r"(syscall_no));
+	asm volatile ("int $0x80"); 
+}
+
+void main()
+{
+	user_syscall(1);
+	return;
+}

src/utils/misc.c

@@ -11,6 +11,8 @@
 #include "../drivers/rtc.h"
 #include "../kernel/io.h"
 #include "../drivers/pci.h"
+#include "../kernel/initrd.h"
+#include "../kernel/kmain.h"
 
 // Print a rainbow colorful text for testing
 
@@ -74,7 +76,7 @@ void program_uptime()
 
 void program_help()
 {
-	printf("help\tpanic\twords\tprimes\trainbow\tclear\nmath\tbf\t   uptime   echo\t  sysinfo\tconway\nrot13   morse\tcowsay   time\t  read\t   reboot\npi\t  ls\t   cat\t  bmp\t   lspci\t  naval\nsnake\n");
+	printf("help\tpanic\twords\tprimes\trainbow\tclear\nmath\tbf\t   uptime   echo\t  sysinfo\tconway\nrot13   morse\tcowsay   time\t  read\t   reboot\npi\t  ls\t   cat\t  bmp\t   lspci\t  naval\nsnake   exec\n");
 }
 
 // Panic
@@ -133,7 +135,7 @@ void program_read(int argc, char* argv[])
 	}
 }
 
-// Reboots the machine (might just shutdown)
+// Reboots the machine (might just shutdown) (or do nothing if youre lucky)
 
 void program_reboot()
 {
@@ -151,3 +153,24 @@ void program_lspci()
 {
 	scan_pci_bus();
 }
+
+// Executes binary file
+
+void program_exec(int argc, char* argv[])
+{
+	if (argc < 2)
+	{
+		puts("Usage: exec <binary>\n");
+		return;
+	} 
+	void* binary_file = load_file_from_initrd((uint8_t*)initrd_addr, argv[1]); 
+
+	if (binary_file == NULL)
+	{
+		printf("[exec] Failed to load program '%s'.\n", argv[1]);
+		return;
+	} 
+
+	void (*program_entry)() = (void (*)())binary_file;
+	program_entry();
+}

src/utils/uhex.c

@@ -0,0 +1,72 @@
+// uhex (microhex) port for BlankOS; read-only version
+// Author: xamidev
+// Licensed under the Unlicense. See the repo below.
+// https://github.com/xamidev/blankos
+
+// This version is the port of a hex viewer which already was not great,
+// and now by being here it is even worse because it is RO and will have
+// hardcoded stuff in it (no ioctl, STDOUT, or other stuff here...)
+
+/*
+
+#define BYTES 1024
+#define round(x) (int)(x < 0 ? (x -0.5) : x + 0.5)
+
+// WIP: pushed but not done yet
+
+void print_hex(unsigned char* buf, int byteno, int pos, int BYTES_PER_LINE)
+{
+	for (int i=0; i<byteno; i++)
+	{
+		if (i%BYTES_PER_LINE == 0)
+		{
+			if (i != 0)
+			{
+				printf(" ");
+				for (int j=i-BYTES_PER_LINE; j<i; j++)
+				{
+					if (isprint(buf[j])) colorprintf(salmon, black, "%c", buf[j]);
+					else printf(".");
+				}
+			}
+			puts("\n");
+
+			if (pos == 0) printf("%06d:   ", i);
+			else printf("%06d:   ", pos);
+		}
+	printf("%2x", buf[i]);
+	}
+
+	int padding = BYTES_PER_LINE - (byteno % BYTES_PER_LINE);
+	if (padding < BYTES_PER_LINE)
+	{
+		for (int i=0; i<padding; i++) printf("   ");
+		printf("  ");
+	}
+	int start = byteno-(byteno%BYTES_PER_LINE);
+	for (int j=start; j<byteno; j++)
+	{
+		if (isprint(buf[j])) {
+			colorprintf(salmon, black, "%c", buf[j]);
+		} else {
+			printf(".");
+		}
+	}
+	puts("\n");
+}
+
+void program_uhex(int argc, char* argv[])
+{
+	if (argc < 2)
+	{
+		printf("Usage: uhex <file>\nInline commands:\n\tpX - print position X\n\teX - edit position X\n\tq - quit\n");
+		return;
+	}
+
+	int BYTES_PER_LINE = 20;
+
+	
+
+}
+
+*/ 

src/utils/utils.h

@@ -3,8 +3,8 @@
 // Licensed under the Unlicense. See the repo below.
 // https://github.com/xamidev/blankos
 
-#ifndef PROGRAMS_H
-#define PROGRAMS_H
+#ifndef UTILS_H
+#define UTILS_H
 
 void program_words();
 void program_primes();
@@ -45,4 +45,7 @@ void program_navalbattle();
 void program_conway();
 void program_snake();
 
+// Binaries loading and execution
+void program_exec();
+
 #endif