Major update

* Implemented Process manager with input support.
* Implemented a ELF loader which loads static linked
* Implemented a syscall handler
* Added a sample program.
* Added new command to the shell
* Added new function to fetch bg and fg color
* Implemented a function to get arguments from grub
* Updated kernel.c
* Updated Makefile
* Updated README.md
* Fixed some warnings the compiler outputted
* Incremented kernel version

Author: Arun007coder

Makefile

@@ -59,6 +59,7 @@ OBJECTS= 	$(SRCDIR)/boot/multiboot.o \
 			$(SRCDIR)/interrupts/interrupt_helper.o \
 			$(SRCDIR)/interrupts/exception.o \
 			$(SRCDIR)/interrupts/exception_helper.o \
+			$(SRCDIR)/interrupts/syscall.o \
 			$(SRCDIR)/common/libs/debug.o \
 			$(SRCDIR)/common/libs/string.o \
 			$(SRCDIR)/common/libs/printf.o \
@@ -79,6 +80,9 @@ OBJECTS= 	$(SRCDIR)/boot/multiboot.o \
 			$(SRCDIR)/memory/paging.o \
 			$(SRCDIR)/memory/pmm.o \
 			$(SRCDIR)/process/usermode.o \
+			$(SRCDIR)/process/process.o \
+			$(SRCDIR)/process/context_switch.o \
+			$(SRCDIR)/process/elf_loader.o \
 			$(SRCDIR)/kernel/shell.o \
 			$(SRCDIR)/kernel/kernel.o
 
@@ -103,7 +107,7 @@ $(ISOFILE): $(IMAGEFILE) $(EXECUTABLE)
 	@echo 'set root=(cd)' >> $(PROJECT)/boot/grub/grub.cfg
 	@echo '' >> $(PROJECT)/boot/grub/grub.cfg
 	@echo 'menuentry "$(PROJECT)" { '>> $(PROJECT)/boot/grub/grub.cfg
-	@echo 'multiboot /boot/$(EXECUTABLE)' >> $(PROJECT)/boot/grub/grub.cfg
+	@echo 'multiboot /boot/$(EXECUTABLE) --root /dev/rdisk0' >> $(PROJECT)/boot/grub/grub.cfg
 	@echo 'module /boot/sorhd' >> $(PROJECT)/boot/grub/grub.cfg
 	@echo 'boot' >> $(PROJECT)/boot/grub/grub.cfg
 	@echo '}' >> $(PROJECT)/boot/grub/grub.cfg
@@ -127,7 +131,7 @@ sorfs_compile:
 	@echo '[CC] $(SRCDIR)/tools/sorfs.c => sorfs'
 	@gcc $(SRCDIR)/tools/sorfs.c -o sorfs
 
-$(IMAGEFILE): sorfs_compile
+$(IMAGEFILE): sorfs_compile create_test_program
 	@echo '[SORFS] $@'
 	./sorfs -c $@ $(wildcard $(FILESDIR)/*)
 
@@ -144,6 +148,9 @@ stripd: $(EXECUTABLE)
 	@$(TOOLDIR)$(OBJCOPY) --only-keep-debug $(EXECUTABLE) debug.sym
 	@$(TOOLDIR)$(OBJCOPY) $(OBJCOPYFLAGS) $(EXECUTABLE)
 
+create_test_program:
+	$(CC) -nostdlib  $(SRCDIR)/tools/user.c -o files/app.elf 
+
 forcerun: clean iso run
 forcerund: clean iso rund
 

docs/README.md

@@ -14,7 +14,7 @@ Kernel Version
 
 
 ## 🧱 Kernel
-The current kernel version for SectorOS-RW4 is v4.23.04.3NR.<br>
+The current kernel version for SectorOS-RW4 is v5.23.04.4NR.<br>
 
 ## ⚙️ Build Steps
 

docs/changelog.txt

@@ -134,4 +134,19 @@
 * Updated kernel.c
 * Incremented kernel version
 * Updated Makefile
-* Updated README.md
+* Updated README.md
+
+09-04-2023: 10:48 PM IST v5.23.04.4NR
+* Major update
+* Implemented Process manager with input support.
+* Implemented a ELF loader which loads static linked
+* Implemented a syscall handler
+* Added a sample program.
+* Added new command to the shell
+* Added new function to fetch bg and fg color
+* Implemented a function to get arguments from grub
+* Updated kernel.c
+* Updated Makefile
+* Updated README.md
+* Fixed some warnings the compiler outputted
+* Incremented kernel version

src/common/libs/bit.c

@@ -12,12 +12,12 @@ uint8_t hibyte(uint16_t data)
 
 void set_hibyte(uint16_t* data, uint8_t num)
 {
-    data = (num << 8);
+    *data = (uint16_t)(num << 8);
 }
 
 void set_lobyte(uint16_t* data, uint8_t num)
 {
-    data = num;
+    *data = (uint16_t)num;
 }
 
 int get_bit(uint32_t data, int num)

src/common/libs/debug.c

@@ -3,7 +3,7 @@
 
 void kernel_panic(const char* message)
 {
-    text_chcolor(VGA_LIGHT_RED, VGA_BLACK);
+    text_chcolor(VGA_LIGHT_RED, text_getBG());
     printf("kernel panic: - %s\n", message);
     while(1);
 }

src/common/libs/list.c

@@ -122,6 +122,18 @@ int list_contain(list_t * list, void * val)
     return -1;
 }
 
+int list_contain_str(list_t* list, char* str)
+{
+    int index = 0;
+    foreach(listnode, list)
+    {
+        if(strcmp(listnode->val, str) == 0)
+            return index;
+        index++;
+    }
+    return -1;
+}
+
 listnode_t * list_get_node_by_index(list_t * list, int index)
 {
     if(index < 0 || index >= list_size(list))

src/drivers/cpu/gdt.c

@@ -1,5 +1,6 @@
 #include "gdt.h"
 #include "bit.h"
+#include "debug.h"
 #include "isr.h"
 
 gdt_entry_t entries[GDT_MAX_ENTRIES];

src/drivers/video/vga_text.c

@@ -116,6 +116,16 @@ void text_chcolor(uint8_t fg, uint8_t bg)
     textmode.fg = fg;
 }
 
+uint8_t text_getBG()
+{
+    return textmode.bg;
+}
+
+uint8_t text_getFG()
+{
+    return textmode.fg;
+}
+
 void text_puts(char* str)
 {
     while(*str)

src/include/elf_loader.h

@@ -0,0 +1,132 @@
+#ifndef __ELF_LOADER_H__
+#define __ELF_LOADER_H__
+
+#include "system.h"
+#include "syscall.h"
+#include "string.h"
+#include "kheap.h"
+#include "vfs.h"
+#include "paging.h"
+#include "printf.h"
+
+#define DEFAULT_ELF_LOAD_ADDR (void*)0x08048000
+
+#define ELF_NIDENT 16
+
+#define ELFMAG0      0x7F
+#define ELFMAG1     'E'
+#define ELFMAG2     'L'
+#define ELFMAG3     'F'
+#define ELFDATA2LSB (1)
+#define ELFCLASS32  (1)
+#define EM_386     (3)
+#define EV_CURRENT (1)
+
+#define SHN_UNDEF  (0x00)
+
+#define PT_NULL             0
+#define PT_LOAD             1
+#define PT_DYNAMIC          2
+#define PT_INTERP           3
+#define PT_NOTE             4
+#define PT_SHLIB            5
+#define PT_PHDR             6
+#define PT_LOPROC  0x70000000
+#define PT_HIPROC  0x7fffffff
+
+#define PF_X    0x1
+#define PF_W    0x2
+#define PF_R    0x4
+
+typedef uint16_t Elf32_Half;
+typedef uint32_t Elf32_Off;
+typedef uint32_t Elf32_Addr;
+typedef uint32_t Elf32_Word;
+typedef int  Elf32_Sword;
+
+enum Elf_Ident
+{
+    EI_MAG1     = 1,
+    EI_MAG0     = 0,
+    EI_MAG3     = 3,
+    EI_MAG2     = 2,
+    EI_DATA     = 5,
+    EI_CLASS    = 4,
+    EI_OSABI    = 7,
+    EI_VERSION  = 6,
+    EI_ABIVERSION   = 8,
+    EI_PAD      = 9
+};
+
+enum Elf_Type
+{
+    ET_NONE     = 0,
+    ET_REL      = 1,
+    ET_EXEC     = 2 
+};
+
+enum ShT_Types
+{
+    SHT_NULL    = 0,
+    SHT_PROGBITS= 1,
+    SHT_SYMTAB  = 2,
+    SHT_STRTAB  = 3,
+    SHT_RELA    = 4,
+    SHT_NOBITS  = 8,
+    SHT_REL     = 9,
+};
+
+enum ShT_Attributes
+{
+    SHF_WRITE   = 0x01,
+    SHF_ALLOC   = 0x02 
+};
+
+
+typedef struct elf_header
+{
+    uint8_t     e_ident[ELF_NIDENT];
+    Elf32_Half  e_type;
+    Elf32_Half  e_machine;
+    Elf32_Word  e_version;
+    Elf32_Addr  e_entry;
+    Elf32_Off   e_phoff;
+    Elf32_Off   e_shoff;
+    Elf32_Word  e_flags;
+    Elf32_Half  e_ehsize;
+    Elf32_Half  e_phentsize;
+    Elf32_Half  e_phnum;
+    Elf32_Half  e_shentsize;
+    Elf32_Half  e_shnum;
+    Elf32_Half  e_shstrndx;
+}elf_header_t;
+
+typedef struct elf_section_header
+{
+    Elf32_Word  sh_name;
+    Elf32_Word  sh_type;
+    Elf32_Word  sh_flags;
+    Elf32_Addr  sh_addr;
+    Elf32_Off   sh_offset;
+    Elf32_Word  sh_size;
+    Elf32_Word  sh_link;
+    Elf32_Word  sh_info;
+    Elf32_Word  sh_addralign;
+    Elf32_Word  sh_entsize;
+}elf_section_header_t;
+
+typedef struct elf_program_header
+{
+    Elf32_Word      p_type;
+    Elf32_Off       p_offset;
+    Elf32_Addr      p_vaddr;
+    Elf32_Addr      p_paddr;
+    Elf32_Word      p_filesz;
+    Elf32_Word      p_memsz;
+    Elf32_Word      p_flags;
+    Elf32_Word      p_align;
+}elf_program_header_t;
+
+void load_elf();
+
+#endif /*__ELF_LOADER_H__*/

src/include/list.h

@@ -42,6 +42,7 @@ void list_destroy(list_t * list);
 void listnode_destroy(listnode_t * node);
 
 int list_contain(list_t * list, void * val);
+int list_contain_str(list_t* list, char* str);
 
 listnode_t * list_get_node_by_index(list_t * list, int index);
 void * list_remove_by_index(list_t * list, int index);