Separated functionality into separate files. Added initial (untested) support for ARM.

arch/arm-none-eabi/boot.s

@@ -0,0 +1,33 @@
+.section ".text.boot"
+
+.globl Start
+Start:
+	// Setup the stack
+	mov	sp, #0x8000
+	
+	// Clear out bss
+	ldr	r4, =_bss_start
+	ldr	r9, =_bss_end
+	mov	r5, #0
+	mov	r6, #0
+	mov	r7, #0
+	mov	r8, #0
+	b	2f
+
+1:
+	// Store multiple at r4
+	stmia	r4!, {r5-r8}
+
+2:
+	// If we are still below bss_end, loop
+	cmp	r4, r9
+	blo	1b
+	
+	// Call brados_main
+	ldr	r3, =brados_main
+	blx	r3
+
+halt:
+	// Halt
+	wfe
+	b	halt

arch/arm-none-eabi/linker.ld

@@ -0,0 +1,42 @@
+ENTRY(Start)
+
+SECTIONS
+{
+	/* Starts at LOADER_ADDR */
+	. = 0x8000
+	_start = .;
+	_text_start = .;
+	.text:
+	{
+		KEEP(*(.text.boot))
+		*(.text)
+	}
+	. = ALIGN(4096);
+	_text_end = .;
+	
+	_rodata_start = .;
+	.rodata:
+	{
+		*(.rodata)
+	}
+	. = ALIGN(4096)
+	_rodata_end = .;
+	
+	_data_start = .;
+	.data:
+	{
+		*(.data)
+	}
+	. = ALIGN(4096);
+	_data_end = .;
+	
+	_bss_start = .;
+	.bss:
+	{
+		bss = .;
+		*(.bss)
+	}
+	. = ALIGN(4096)
+	_bss_end = .;
+	_end = .;
+}

arch/i586-elf/boot.s

@@ -0,0 +1,40 @@
+# Declare constants for creating a multiboot header
+.set ALIGN,	1<<0
+.set MEMINFO,	1<<1
+.set FLAGS,	ALIGN | MEMINFO
+.set MAGIC,	0x1BADB002
+.set CHECKSUM,	-(MAGIC + FLAGS)
+
+# Declare multiboot header
+.section .multiboot
+.align 4
+.long MAGIC
+.long FLAGS
+.long CHECKSUM
+
+# Create a 16 KiB stack
+.section .bootstrap_stack
+stack_bottom:
+.skip 16384
+stack_top:
+
+# Kernel entry point
+.section .text
+.global _start
+.type _start, @function
+_start:
+	# We are now in kernel mode!
+	# Setup the stack
+	movl $stack_top, %esp
+	
+	# Call the main kernel function
+	call brados_main
+	
+	# In case the function returns, enter an endless loop
+	cli
+	hlt
+.Lhang:
+	jmp .Lhang
+
+# Set the size of the _start symbol for debugging
+.size _start, . - _start

arch/i586-elf/linker.ld

@@ -0,0 +1,38 @@
+/* Kernel entry point */
+ENTRY(_start)
+
+/* Define the locations of the object file sections */
+SECTIONS
+{
+	/* Sections begin at 1 MiB */
+	. = 1M;
+	
+	/* The multiboot header needs to come first, followed by program code */
+	.text BLOCK(4K) : ALIGN(4K)
+	{
+		*(.multiboot)
+		*(.text)
+	}
+	
+	/* Read-only data */
+	.rodata BLOCK(4K) : ALIGN(4K)
+	{
+		*(.rodata)
+	}
+	
+	/* Initialized read-write data */
+	.data BLOCK(4K) : ALIGN(4K)
+	{
+		*(.data)
+	}
+	
+	/* Uninitialized read-write data and stack */
+	.bss BLOCK(4K) : ALIGN(4K)
+	{
+		*(COMMON)
+		*(.bss)
+		*(.bootstrap_stack)
+	}
+	
+	/* Add other sections here */
+}