holy crap i got it to boot! 😄

gems-kernel.git/build.sh

@@ -7,12 +7,12 @@ mkdir builds/iso
 mkdir builds/iso/boot
 mkdir builds/iso/boot/grub
 echo "Building bootloader"
-nasm -f elf32 source/bootloader.asm -o builds/blocks/bl.o
+nasm -f elf32 source/bootloader.asm -o builds/blocks/bootloader.o
 echo "Building basic keyboard support"
 nasm -f elf32 source/detect-kbinput.asm -o builds/blocks/detectkeys.o
 echo "Building OS"
 set disassembly-flavor intel
-opt/cross/bin/i686-elf-gcc builds/blocks/bl.o -ffreestanding -nostdlib builds/blocks/detectkeys.o source/os.c -w -g -m32 -o builds/iso/gems.elf -I"/usr/include" -I"source/THIRDPARTY/lwext4-master/include/" -I"source/THIRDPARTY/linux-old/include/linux" -I"source/THIRDPARTY/linux-old/include/asm"
+opt/cross/bin/i686-elf-gcc builds/blocks/bootloader.o -ffreestanding -nostdlib builds/blocks/detectkeys.o source/os.c -w -g -m32 -o builds/iso/gems.elf -I"/usr/include" -I"source/THIRDPARTY/lwext4-master/include/" -I"source/THIRDPARTY/linux-old/include/linux" -I"source/THIRDPARTY/linux-old/include/asm"
 echo "Creating GRUB config"
 echo "set default=0" > builds/iso/boot/grub/grub.cfg
 echo "set timeout=60" >> builds/iso/boot/grub/grub.cfg

gems-kernel.git/linker.ld

@@ -0,0 +1,52 @@
+/* The bootloader will look at this image and start execution at the symbol
+   designated as the entry point. */
+ENTRY(_start)
+ 
+/* Tell where the various sections of the object files will be put in the final
+   kernel image. */
+SECTIONS
+{
+	/* It used to be universally recommended to use 1M as a start offset,
+	   as it was effectively guaranteed to be available under BIOS systems.
+	   However, UEFI has made things more complicated, and experimental data
+	   strongly suggests that 2M is a safer place to load. In 2016, a new
+	   feature was introduced to the multiboot2 spec to inform bootloaders
+	   that a kernel can be loaded anywhere within a range of addresses and
+	   will be able to relocate itself to run from such a loader-selected
+	   address, in order to give the loader freedom in selecting a span of
+	   memory which is verified to be available by the firmware, in order to
+	   work around this issue. This does not use that feature, so 2M was
+	   chosen as a safer option than the traditional 1M. */
+	. = 2M;
+ 
+	/* First put the multiboot header, as it is required to be put very early
+	   in the image or the bootloader won't recognize the file format.
+	   Next we'll put the .text section. */
+	.text BLOCK(4K) : ALIGN(4K)
+	{
+		*(.multiboot)
+		*(.text)
+	}
+ 
+	/* Read-only data. */
+	.rodata BLOCK(4K) : ALIGN(4K)
+	{
+		*(.rodata)
+	}
+ 
+	/* Read-write data (initialized) */
+	.data BLOCK(4K) : ALIGN(4K)
+	{
+		*(.data)
+	}
+ 
+	/* Read-write data (uninitialized) and stack */
+	.bss BLOCK(4K) : ALIGN(4K)
+	{
+		*(COMMON)
+		*(.bss)
+	}
+ 
+	/* The compiler may produce other sections, by default it will put them in
+	   a segment with the same name. Simply add stuff here as needed. */
+}

gems-kernel.git/quick-test.sh

@@ -0,0 +1,5 @@
+if grub-file --is-x86-multiboot builds/iso/gems.elf; then
+  echo multiboot confirmed
+else
+  echo the file is not multiboot
+fi

gems-kernel.git/source/bootloader.asm

@@ -1,16 +1,90 @@
-SECTION .multiboot
+; Declare constants for the multiboot header.
-ALIGN 4
+MBALIGN  equ  1 << 0            ; align loaded modules on page boundaries
-extern kern
+MEMINFO  equ  1 << 1            ; provide memory map
-mboot:
+MBFLAGS  equ  MBALIGN | MEMINFO ; this is the Multiboot 'flag' field
-    mov ax, 9ch
+MAGIC    equ  0x1BADB002        ; 'magic number' lets bootloader find the header
-    mov ss, ax ;cannot be written directly
+CHECKSUM equ -(MAGIC + MBFLAGS)   ; checksum of above, to prove we are multiboot
-    mov sp, 4094d
+ 
-    mov ax, 7c0h
+; Declare a multiboot header that marks the program as a kernel. These are magic
-    mov ds, ax ;cannot be written directly
+; values that are documented in the multiboot standard. The bootloader will
-    call kern
+; search for this signature in the first 8 KiB of the kernel file, aligned at a
-quit:
+; 32-bit boundary. The signature is in its own section so the header can be
-    hlt
+; forced to be within the first 8 KiB of the kernel file.
-    jmp quit
+section .multiboot
-    jmp $
+align 4
-    times 510-($-$$) db 0
+	dd MAGIC
-    dw 0xAA55
+	dd MBFLAGS
+	dd CHECKSUM
+ 
+; The multiboot standard does not define the value of the stack pointer register
+; (esp) and it is up to the kernel to provide a stack. This allocates room for a
+; small stack by creating a symbol at the bottom of it, then allocating 16384
+; bytes for it, and finally creating a symbol at the top. The stack grows
+; downwards on x86. The stack is in its own section so it can be marked nobits,
+; which means the kernel file is smaller because it does not contain an
+; uninitialized stack. The stack on x86 must be 16-byte aligned according to the
+; System V ABI standard and de-facto extensions. The compiler will assume the
+; stack is properly aligned and failure to align the stack will result in
+; undefined behavior.
+section .bss
+align 16
+stack_bottom:
+resb 16384 ; 16 KiB
+stack_top:
+ 
+; The linker script specifies _start as the entry point to the kernel and the
+; bootloader will jump to this position once the kernel has been loaded. It
+; doesn't make sense to return from this function as the bootloader is gone.
+; Declare _start as a function symbol with the given symbol size.
+section .text
+global _start:function (_start.end - _start)
+_start:
+	; The bootloader has loaded us into 32-bit protected mode on a x86
+	; machine. Interrupts are disabled. Paging is disabled. The processor
+	; state is as defined in the multiboot standard. The kernel has full
+	; control of the CPU. The kernel can only make use of hardware features
+	; and any code it provides as part of itself. There's no printf
+	; function, unless the kernel provides its own <stdio.h> header and a
+	; printf implementation. There are no security restrictions, no
+	; safeguards, no debugging mechanisms, only what the kernel provides
+	; itself. It has absolute and complete power over the
+	; machine.
+ 
+	; To set up a stack, we set the esp register to point to the top of our
+	; stack (as it grows downwards on x86 systems). This is necessarily done
+	; in assembly as languages such as C cannot function without a stack.
+	mov esp, stack_top
+ 
+	; This is a good place to initialize crucial processor state before the
+	; high-level kernel is entered. It's best to minimize the early
+	; environment where crucial features are offline. Note that the
+	; processor is not fully initialized yet: Features such as floating
+	; point instructions and instruction set extensions are not initialized
+	; yet. The GDT should be loaded here. Paging should be enabled here.
+	; C++ features such as global constructors and exceptions will require
+	; runtime support to work as well.
+ 
+	; Enter the high-level kernel. The ABI requires the stack is 16-byte
+	; aligned at the time of the call instruction (which afterwards pushes
+	; the return pointer of size 4 bytes). The stack was originally 16-byte
+	; aligned above and we've since pushed a multiple of 16 bytes to the
+	; stack since (pushed 0 bytes so far) and the alignment is thus
+	; preserved and the call is well defined.
+        ; note, that if you are building on Windows, C functions may have "_" prefix in assembly: _kernel_main
+	extern kernel_main
+	call kernel_main
+ 
+	; If the system has nothing more to do, put the computer into an
+	; infinite loop. To do that:
+	; 1) Disable interrupts with cli (clear interrupt enable in eflags).
+	;    They are already disabled by the bootloader, so this is not needed.
+	;    Mind that you might later enable interrupts and return from
+	;    kernel_main (which is sort of nonsensical to do).
+	; 2) Wait for the next interrupt to arrive with hlt (halt instruction).
+	;    Since they are disabled, this will lock up the computer.
+	; 3) Jump to the hlt instruction if it ever wakes up due to a
+	;    non-maskable interrupt occurring or due to system management mode.
+	cli
+.hang:	hlt
+	jmp .hang
+.end:

gems-kernel.git/source/debug.h

@@ -78,5 +78,5 @@ void panic(char deets[128]) {
     print("\nAre colors working? (Order: Blue,Green,Lightblue,Red,Pink,Orange,White.)\n");
     showColors();
     print("Regular\n");
-    halt();
+    halt(1);
 }

gems-kernel.git/source/linker.ld

@@ -1,41 +1,52 @@
+/* The bootloader will look at this image and start execution at the symbol
+   designated as the entry point. */
+ENTRY(_start)
+ 
+/* Tell where the various sections of the object files will be put in the final
+   kernel image. */
 SECTIONS
 {
-  .text.start (_KERNEL_BASE_) : {
+	/* It used to be universally recommended to use 1M as a start offset,
-/* link multiboot struct */
+	   as it was effectively guaranteed to be available under BIOS systems.
-. = ALIGN(8);
+	   However, UEFI has made things more complicated, and experimental data
-KEEP(*(.multiboot))
+	   strongly suggests that 2M is a safer place to load. In 2016, a new
-/* keep this */
+	   feature was introduced to the multiboot2 spec to inform bootloaders
-    startup.o( .text )
+	   that a kernel can be loaded anywhere within a range of addresses and
-  }
+	   will be able to relocate itself to run from such a loader-selected
+	   address, in order to give the loader freedom in selecting a span of
+	   memory which is verified to be available by the firmware, in order to
+	   work around this issue. This does not use that feature, so 2M was
+	   chosen as a safer option than the traditional 1M. */
+	. = 2M;
  
-  .text : ALIGN(0x1000) {
+	/* First put the multiboot header, as it is required to be put very early
-/* link multiboot struct */
+	   in the image or the bootloader won't recognize the file format.
-. = ALIGN(8);
+	   Next we'll put the .text section. */
-KEEP(*(.multiboot))
+	.text BLOCK(4K) : ALIGN(4K)
-/* keep this */
+	{
-_TEXT_START_ = .;
+		*(.multiboot)
-    *(.text)
+		*(.text)
-_TEXT_END_ = .;
+	}
-  }
  
-  .data : ALIGN(0x1000) {
+	/* Read-only data. */
-/* link multiboot struct */
+	.rodata BLOCK(4K) : ALIGN(4K)
-. = ALIGN(8);
+	{
-KEEP(*(.multiboot))
+		*(.rodata)
-/* keep this */
+	}
-_DATA_START_ = .;
-    *(.data)
-_DATA_END_ = .;
-  }
  
-  .bss : ALIGN(0x1000) {
+	/* Read-write data (initialized) */
-/* link multiboot struct */
+	.data BLOCK(4K) : ALIGN(4K)
-. = ALIGN(8);
+	{
-KEEP(*(.multiboot))
+		*(.data)
-/* keep this */
+	}
-_BSS_START_ = .;
+ 
-    *(.bss)
+	/* Read-write data (uninitialized) and stack */
-_BSS_END_ = .;
+	.bss BLOCK(4K) : ALIGN(4K)
-  }
+	{
+		*(COMMON)
+		*(.bss)
+	}
+ 
+	/* The compiler may produce other sections, by default it will put them in
+	   a segment with the same name. Simply add stuff here as needed. */
 }
-

gems-kernel.git/source/os.c

@@ -63,15 +63,15 @@ void os() {
 	while ( 1 == 1 ) {
 		rloadstring("basickeys");
 	}
-	panic("RUSHELL-LEVEL CRASH");
 }
 
 void kern() {
 	//extern bootloader();
 	//bootloader();
+    haltLoop();
 	clear(lastVGATextColor());
 	print("GEMS OK, WAITING A FEW TICKS TO TEST TIME... \n");
-	wait(100000000); //ok? ok.
+	wait(10); //ok? ok.
 	beep();
 	print("Getting frequency of A2 \n");
 	print("(might be garbled until fixed) \n");
@@ -84,10 +84,6 @@ void kern() {
 	waitSecs(5);
 	clear();
 	os();
-	while (1 == 1)
-	{
-	panic("KERNEL-LEVEL CRASH");
-	}
 }
 
 int kernel_main(struct multiboot_info* mbd, unsigned int magic) {

gems-kernel.git/source/start.s

@@ -1,53 +1,52 @@
-// We declare the 'kernel_main' label as being external to this file.
+/* The bootloader will look at this image and start execution at the symbol
-// That's because it's the name of the main C function in 'kernel.c'.
+   designated as the entry point. */
-.extern kernel_main
+ENTRY(_start)
  
-// We declare the 'start' label as global (accessible from outside this file), since the linker will need to know where it is.
+/* Tell where the various sections of the object files will be put in the final
-// In a bit, we'll actually take a look at the code that defines this label.
+   kernel image. */
-.global start
+SECTIONS
+{
+	/* It used to be universally recommended to use 1M as a start offset,
+	   as it was effectively guaranteed to be available under BIOS systems.
+	   However, UEFI has made things more complicated, and experimental data
+	   strongly suggests that 2M is a safer place to load. In 2016, a new
+	   feature was introduced to the multiboot2 spec to inform bootloaders
+	   that a kernel can be loaded anywhere within a range of addresses and
+	   will be able to relocate itself to run from such a loader-selected
+	   address, in order to give the loader freedom in selecting a span of
+	   memory which is verified to be available by the firmware, in order to
+	   work around this issue. This does not use that feature, so 2M was
+	   chosen as a safer option than the traditional 1M. */
+	. = 2M;
  
-// Our bootloader, GRUB, needs to know some basic information about our kernel before it can boot it.
+	/* First put the multiboot header, as it is required to be put very early
-// We give GRUB this information using a standard known as 'Multiboot'.
+	   in the image or the bootloader won't recognize the file format.
-// To define a valid 'Multiboot header' that will be recognised by GRUB, we need to hard code some
+	   Next we'll put the .text section. */
-// constants into the executable. The following code calculates those constants.
+	.text BLOCK(4K) : ALIGN(4K)
-.set MB_MAGIC, 0x1BADB002          // This is a 'magic' constant that GRUB will use to detect our kernel's location.
+	{
-.set MB_FLAGS, (1 << 0) | (1 << 1) // This tells GRUB to 1: load modules on page boundaries and 2: provide a memory map (this is useful later in development)
+		*(.multiboot)
-// Finally, we calculate a checksum that includes all the previous values
+		*(.text)
-.set MB_CHECKSUM, (0 - (MB_MAGIC + MB_FLAGS))
+	}
  
-// We now start the section of the executable that will contain our Multiboot header
+	/* Read-only data. */
-.section .multiboot
+	.rodata BLOCK(4K) : ALIGN(4K)
-	.align 4 // Make sure the following data is aligned on a multiple of 4 bytes
+	{
-	// Use the previously calculated constants in executable code
+		*(.rodata)
-	.long MB_MAGIC
+	}
-	.long MB_FLAGS
-	// Use the checksum we calculated earlier
-	.long MB_CHECKSUM
  
-// This section contains data initialised to zeroes when the kernel is loaded
+	/* Read-write data (initialized) */
-.section .bss
+	.data BLOCK(4K) : ALIGN(4K)
-	// Our C code will need a stack to run. Here, we allocate 4096 bytes (or 4 Kilobytes) for our stack.
+	{
-	// We can expand this later if we want a larger stack. For now, it will be perfectly adequate.
+		*(.data)
-	.align 16
+	}
-	stack_bottom:
-		.skip 4096 // Reserve a 4096-byte (4K) stack
-	stack_top:
  
-// This section contains our actual assembly code to be run when our kernel loads
+	/* Read-write data (uninitialized) and stack */
-.section .text
+	.bss BLOCK(4K) : ALIGN(4K)
-	// Here is the 'start' label we mentioned before. This is the first code that gets run in our kernel.
+	{
-	start:
+		*(COMMON)
-		// First thing's first: we want to set up an environment that's ready to run C code.
+		*(.bss)
-		// C is very relaxed in its requirements: All we need to do is to set up the stack.
+	}
-		// Please note that on x86, the stack grows DOWNWARD. This is why we start at the top.
-		mov $stack_top, %esp // Set the stack pointer to the top of the stack
  
-		// Now we have a C-worthy (haha!) environment ready to run the rest of our kernel.
+	/* The compiler may produce other sections, by default it will put them in
-		// At this point, we can call our main C function.
+	   a segment with the same name. Simply add stuff here as needed. */
-		call kernel_main
+}
- 
-		// If, by some mysterious circumstances, the kernel's C code ever returns, all we want to do is to hang the CPU
-		hang:
-			cli      // Disable CPU interrupts
-			hlt      // Halt the CPU
-			jmp hang // If that didn't work, loop around and try again.

gems-kernel.git/source/time.h

@@ -1,7 +1,7 @@
 //Made to create time at 100000000 TPS
 //by Sparksammy
 int time = 1;
-
+int halted = 0;
 void countOld() {
 	static long long int i; 
 	static int state = 0; 
@@ -20,12 +20,12 @@ void countOld() {
 	
 }
 
-void halt() {
+void halt(int halt) {
-// do nothing.
+    halted = halt;
 }
 
 void wait(uint32_t millis) {
-    uint32_t countdown = millis * 1193181.66667;
+    uint32_t countdown = millis * 1000;
     while (countdown > 0) {
         uint32_t countdown = countdown - 1;
     }
@@ -67,3 +67,14 @@ void disableCount() {
 void enableCount() {
 	countstate = true;
 }
+
+void haltLoop() {
+    while (true) {
+        if (halted == 0) {
+            break;
+        }
+        if (halted == 1) {
+            continue;
+        }
+    }
+}