Merge pull request #12 from xamidev/programs

Programs: loading, 1 fake syscall.. (bad)

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;
@@ -186,3 +199,52 @@ 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