diff --git a/Rakefile b/Rakefile
index 86ca2e1..5976113 100644
--- a/Rakefile
+++ b/Rakefile
@@ -22,31 +22,44 @@ def assemble_stage(output, compiler, source)
 end
 
 desc 'Final stage'
-task default: ['build/stage2', 'boot/stage2.elna'] do |t|
-  assembler, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
+task default: ['build/stage2b', 'build/stage2b.s', 'boot/stage2.elna'] do |t|
+  exe, previous_output, source = t.prerequisites
 
-  File.open File::NULL, 'w' do |output|
-    assemble_stage output, exe, assembler
-  end
+  cat_arguments = ['cat', source]
+  compiler_arguments = [QEMU, '-L', SYSROOT, exe]
+  diff_arguments = ['diff', '-Nur', previous_output, '-']
+  Open3.pipeline(cat_arguments, compiler_arguments, diff_arguments)
 end
 
 directory 'build'
 
 desc 'Initial stage'
-file 'build/stage1' => ['boot/echo-boot.s', 'boot/common-boot.s', 'build'] do |t|
-  assembler = t.prerequisites.filter { |prerequisite| prerequisite.end_with? '.s' }
+file 'build/stage1' => ['boot/stage1.s', 'boot/common-boot.s', 'build'] do |t|
+  source = t.prerequisites.filter { |prerequisite| prerequisite.end_with? '.s' }
 
-  sh CROSS_GCC, '-nostdlib', '-o', t.name, *assembler
+  sh CROSS_GCC, '-nostdlib', '-o', t.name, *source
 end
 
-file 'build/stage2.s' => ['build/stage1', 'boot/stage2.elna'] do |t|
-  assembler, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
+file 'build/stage2a.s' => ['build/stage1', 'boot/stage2.elna'] do |t|
+  source, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
 
   File.open t.name, 'w' do |output|
-    assemble_stage output, exe, assembler
+    assemble_stage output, exe, source
   end
 end
 
-file 'build/stage2' => ['build/stage2.s', 'boot/common-boot.s'] do |t|
+file 'build/stage2a' => ['build/stage2a.s', 'boot/common-boot.s'] do |t|
+  sh CROSS_GCC, '-nostdlib', '-o', t.name, *t.prerequisites
+end
+
+file 'build/stage2b.s' => ['build/stage2a', 'boot/stage2.elna'] do |t|
+  source, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
+
+  File.open t.name, 'w' do |output|
+    assemble_stage output, exe, source
+  end
+end
+
+file 'build/stage2b' => ['build/stage2b.s', 'boot/common-boot.s'] do |t|
   sh CROSS_GCC, '-nostdlib', '-o', t.name, *t.prerequisites
 end
diff --git a/boot/asm-boot.s b/boot/asm-boot.s
deleted file mode 100644
index fca0d3f..0000000
--- a/boot/asm-boot.s
+++ /dev/null
@@ -1,894 +0,0 @@
-# s1 - Contains the current position in the source text.
-
-.global _start # Program entry point.
-
-.section .rodata
-
-.equ SOURCE_BUFFER_SIZE, 2048
-
-asm_begin: .ascii ".text\n.global _start\n_start:\naddi sp, sp, -64\nsw ra, 60(sp)\nsw s0, 56(sp)\naddi s0, sp, 64\n"
-.equ ASM_BEGIN_SIZE, . - asm_begin
-asm_end: .ascii "addi a0, zero, 0\naddi a7, zero, 93\necall\nlw ra, 60(sp)\nlw s0, 56(sp)\naddi sp, sp, 64\nret\n"
-.equ ASM_END_SIZE, . - asm_end
-asm_program: .ascii ".bss\n"
-.equ ASM_PROGRAM_SIZE, . - asm_program
-asm_type: .ascii ".type "
-.equ ASM_TYPE_SIZE, . - asm_type
-asm_object: .ascii ", @object\n"
-.equ ASM_OBJECT_SIZE, . - asm_object
-asm_size: .ascii ".size "
-.equ ASM_SIZE_SIZE, . - asm_size
-asm_zero: .ascii ".zero "
-.equ ASM_ZERO_SIZE, . - asm_zero
-asm_global: .ascii ".global "
-.equ ASM_GLOBAL_SIZE, . - asm_global
-
-token_begin: .string "begin"
-token_end: .string "end"
-token_import: .string "import"
-token_open_paren: .string "("
-token_close_paren: .string ")"
-token_open_square: .string "["
-token_assign: .string ":="
-token_var: .string "var"
-token_comma: .string ","
-
-space: .ascii " "
-comma: .ascii ","
-new_line: .ascii "\n"
-colon: .ascii ":"
-digit_zero: .ascii "0"
-
-instruction_la: .ascii "la"
-instruction_call: .ascii "call"
-instruction_addi: .ascii "addi"
-instruction_li: .ascii "li"
-instruction_sw: .ascii "sw"
-instruction_lw: .ascii "lw"
-
-register_a0: .ascii "a0"
-register_sp: .ascii "sp"
-register_a: .ascii "a"
-
-.section .bss
-.global source_code
-.type source_code, @object
-.size source_code, SOURCE_BUFFER_SIZE
-source_code: .zero SOURCE_BUFFER_SIZE
-
-.section .text
-
-.type _skip_spaces, @function
-_skip_spaces:
-.Lspace_loop_do:
-	lbu t0, (s1) # t0 = Current character.
-
-	li t1, ' '
-	beq t0, t1, .Lspace_loop_repeat
-	li t1, '\t'
-	beq t0, t1, .Lspace_loop_repeat
-	li t1, '\n'
-	beq t0, t1, .Lspace_loop_repeat
-	li t1, '\r'
-	beq t0, t1, .Lspace_loop_repeat
-
-	j .Lspace_loop_end
-.Lspace_loop_repeat:
-	addi s1, s1, 1
-	j .Lspace_loop_do
-
-.Lspace_loop_end:
-	ret
-
-# Compares two string, which of one has a length, the other one is null-terminated.
-#
-# a0 - The address of the token string.
-# a1 - The length of the string in a0.
-# a2 - The address of the null-terminated string.
-#
-# If the strings match sets a0 to 0, otherwise sets it to 1.
-.type _token_compare, @function
-_token_compare:
-	addi t0, a0, 0
-	addi t1, a1, 0
-	addi t2, a2, 0
-
-.Ltoken_compare_loop:
-	lbu t3, (t2)
-
-	# Will only be 0 if the current character in the null terminated string is \0 and the remaining length of the
-	# another string is 0.
-	or t4, t3, t1
-	beqz t4, .Ltoken_compare_equal
-
-	beqz t1, .Ltoken_compare_not_equal
-	beqz t3, .Ltoken_compare_not_equal
-
-	lbu t4, (t0)
-	bne t3, t4, .Ltoken_compare_not_equal
-
-	addi t0, t0, 1
-	addi t1, t1, -1
-	addi t2, t2, 1
-	j .Ltoken_compare_loop
-
-.Ltoken_compare_not_equal:
-	li a0, 1
-	j .Ltoken_compare_end
-
-.Ltoken_compare_equal:
-	li a0, 0
-
-.Ltoken_compare_end:
-	ret
-
-# Reads a token and returns its length in a0.
-# _read_token doesn't change s1, it finds the length of the token s1 is pointing to.
-.type _read_token, @function
-_read_token:
-	# Prologue.
-	addi sp, sp, -16
-	sw ra, 12(sp)
-	sw s0, 8(sp)
-	addi s0, sp, 16
-
-	lbu t0, (s1) # t0 = Current character.
-	sw zero, 4(sp)
-
-	li t1, '.'
-	beq t0, t1, .Ltoken_character_single
-
-	li t1, ','
-	beq t0, t1, .Ltoken_character_single
-
-	li t1, ':'
-	beq t0, t1, .Ltoken_character_colon
-
-	li t1, ';'
-	beq t0, t1, .Ltoken_character_single
-
-	li t1, '('
-	beq t0, t1, .Ltoken_character_single
-
-	li t1, ')'
-	beq t0, t1, .Ltoken_character_single
-
-	li t1, '['
-	beq t0, t1, .Ltoken_character_single
-
-	li t1, ']'
-	beq t0, t1, .Ltoken_character_single
-
-.Ltoken_character_loop_do: # Expect an identifier or a number.
-	lw t6, 4(sp)
-	add t1, s1, t6
-	lbu a0, (t1) # a0 = Current character.
-
-	call is_alnum
-
-	beqz a0, .Ltoken_character_end
-	lw t6, 4(sp)
-	addi t6, t6, 1
-	sw t6, 4(sp)
-	j .Ltoken_character_loop_do
-
-.Ltoken_character_single:
-	lw t6, 4(sp)
-	addi t6, t6, 1
-	sw t6, 4(sp)
-	j .Ltoken_character_end
-
-.Ltoken_character_colon:
-	lbu t0, 1(s1) # t0 = The character after the colon.
-	lw t6, 4(sp)
-	addi t6, t6, 1
-	sw t6, 4(sp)
-
-	li t1, '='
-	beq t0, t1, .Ltoken_character_single
-	j .Ltoken_character_end
-
-.Ltoken_character_end:
-	lw a0, 4(sp)
-
-	# Epilogue.
-	lw ra, 12(sp)
-	lw s0, 8(sp)
-	addi sp, sp, 16
-	ret
-
-# Generate entry point symbol.
-.type _compile_begin, @function
-_compile_begin:
-	# Prologue.
-	addi sp, sp, -8
-	sw ra, 4(sp)
-	sw s0, 0(sp)
-	addi s0, sp, 8
-
-	# Write initial assembler.
-	la a0, asm_begin
-	addi a1, zero, ASM_BEGIN_SIZE
-	call write_out
-
-	addi s1, s1, 5
-
-	# Epilogue.
-	lw ra, 4(sp)
-	lw s0, 0(sp)
-	addi sp, sp, 8
-	ret
-
-# Generate program termination code.
-.type _compile_end, @function
-_compile_end:
-	# Prologue.
-	addi sp, sp, -8
-	sw ra, 4(sp)
-	sw s0, 0(sp)
-	addi s0, sp, 8
-
-	# Write closing assembler.
-	la a0, asm_end
-	addi a1, zero, ASM_END_SIZE
-	call write_out
-
-	addi s1, s1, 3
-
-	# Epilogue.
-	lw ra, 4(sp)
-	lw s0, 0(sp)
-	addi sp, sp, 8
-	ret
-
-# Ignores the import.
-.type _compile_import, @function
-_compile_import:
-	# Prologue.
-	addi sp, sp, -8
-	sw ra, 4(sp)
-	sw s0, 0(sp)
-	addi s0, sp, 8
-
-	addi s1, s1, 6
-	call _skip_spaces
-	call _read_token
-	add s1, s1, a0 # Skip the imported module name.
-
-	# Epilogue.
-	lw ra, 4(sp)
-	lw s0, 0(sp)
-	addi sp, sp, 8
-	ret
-
-# Compiles a procedure call. Expects s1 to point to the first argument.
-# a0 - Pointer to the procedure name.
-# a1 - Length of the procedure name.
-#
-# Returns the procedure result in a0.
-.type _compile_call, @function
-_compile_call:
-	# Prologue.
-	addi sp, sp, -32
-	sw ra, 28(sp)
-	sw s0, 24(sp)
-	addi s0, sp, 32
-
-	sw a0, 20(sp)
-	sw a1, 16(sp)
-	sw zero, 12(sp) # Argument count for a procedure call.
-
-.Lcompile_call_paren:
-	call _skip_spaces
-	call _read_token
-	addi a1, a0, 0
-	addi a0, s1, 0
-	la a2, token_close_paren
-	call _token_compare
-	beqz a0, .Lcompile_call_complete
-
-.Lcompile_call_argument:
-	call _build_expression
-
-	la a0, instruction_sw
-	li a1, 2
-	call write_out
-
-	la a0, space
-	li a1, 1
-	call write_out
-
-	la a0, register_a0
-	li a1, 2
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	lw t0, 12(sp) # Argument count for a procedure call.
-
-	# Only 8 arguments are supported with a0-a7.
-	# Save all arguments on the stack so they aren't overriden afterwards.
-	# The offset on the stack always has two digits in this case.
-	li t1, -4
-	mul t1, t0, t1
-	addi t1, t1, 52
-	li t2, 10
-	div t3, t1, t2
-	rem t4, t1, t2
-	addi t3, t3, '0'
-	addi t4, t4, '0'
-
-	sw t3, 8(sp)
-	sw t4, 4(sp)
-
-	addi a0, sp, 8
-	li a1, 1
-	call write_out
-
-	addi a0, sp, 4
-	li a1, 1
-	call write_out
-
-	la a0, token_open_paren
-	li a1, 1
-	call write_out
-
-	la a0, register_sp
-	li a1, 2
-	call write_out
-
-	la a0, token_close_paren
-	li a1, 1
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	call _skip_spaces
-	call _read_token
-	addi a1, a0, 0
-	addi a0, s1, 0
-	la a2, token_comma
-	call  _token_compare
-
-	bnez a0, .Lcompile_call_paren
-
-	lw t0, 12(sp) # Argument count for a procedure call.
-	addi t0, t0, 1
-	sw t0, 12(sp)
-
-	addi s1, s1, 1 # Skip the comma between the arguments.
-	j .Lcompile_call_argument
-
-.Lcompile_call_complete:
-	sw zero, 12(sp)
-
-.Lcompile_call_restore:
-	# Just go through all a0-a7 registers and read them from stack.
-	# If this stack value contains garbage, the procedure just shouldn't use it.
-	lw t0, 12(sp)
-	li t1, 7
-	bgt t0, t1, .Lcompile_call_perform
-
-	la a0, instruction_lw
-	li a1, 2
-	call write_out
-
-	la a0, space
-	li a1, 1
-	call write_out
-
-	la a0, register_a
-	li a1, 1
-	call write_out
-
-	lw t0, 12(sp)
-	addi t0, t0, '0'
-	sw t0, 8(sp)
-
-	addi a0, sp, 8
-	li a1, 1
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	lw t0, 12(sp) # Argument count for a procedure call.
-
-	li t1, -4
-	mul t1, t0, t1
-	addi t1, t1, 52
-	li t2, 10
-	div t3, t1, t2
-	rem t4, t1, t2
-	addi t3, t3, '0'
-	addi t4, t4, '0'
-
-	sw t3, 8(sp)
-	sw t4, 4(sp)
-
-	addi a0, sp, 8
-	li a1, 1
-	call write_out
-
-	addi a0, sp, 4
-	li a1, 1
-	call write_out
-
-	la a0, token_open_paren
-	li a1, 1
-	call write_out
-
-	la a0, register_sp
-	li a1, 2
-	call write_out
-
-	la a0, token_close_paren
-	li a1, 1
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	lw t0, 12(sp) # Increment.
-	addi t0, t0, 1
-	sw t0, 12(sp)
-
-	j .Lcompile_call_restore
-
-.Lcompile_call_perform:
-	la a0, instruction_call
-	li a1, 4
-	call write_out
-
-	la a0, space
-	li a1, 1
-	call write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	call _skip_spaces
-	addi s1, s1, 1 # Skip the close paren.
-
-	# Epilogue.
-	lw ra, 28(sp)
-	lw s0, 24(sp)
-	addi sp, sp, 32
-	ret
-
-.type _compile, @function
-compile:
-	# Prologue.
-	addi sp, sp, -16
-	sw ra, 12(sp)
-	sw s0, 8(sp)
-	addi s0, sp, 16
-
-	# Write .bss section header for global variables.
-	la a0, asm_program
-	addi a1, zero, ASM_PROGRAM_SIZE
-	call write_out
-
-	call _skip_spaces
-	addi s1, s1, 7 # Skip "program" keyword.
-
-.Lcharacter_loop_do:
-	call _skip_spaces
-
-	lbu t0, (s1) # t0 = Current character.
-	beqz t0, .Lcharacter_loop_end
-
-	call _read_token
-	sw a0, 4(sp) # Save the token length on the stack.
-	beqz a0, .Lcharacter_loop_end # No token read, there is unrecognized input.
-
-	lw a0, 4(sp)
-	call _handle_token
-
-	j .Lcharacter_loop_do
-.Lcharacter_loop_end:
-
-	# Epilogue.
-	lw ra, 12(sp)
-	lw s0, 8(sp)
-	addi sp, sp, 16
-	ret
-
-# Evalutes an expression and saves the result in a0.
-.type _build_expression, @function
-_build_expression:
-	# Prologue.
-	addi sp, sp, -16
-	sw ra, 12(sp)
-	sw s0, 8(sp)
-	addi s0, sp, 16
-
-	call _skip_spaces
-	call _read_token
-	sw s1, 4(sp)
-	sw a0, 0(sp)
-
-	# Integer literal.
-	addi a0, s1, 0
-	lb a0, (a0)
-	call is_digit
-	bnez a0, .Lbuild_expression_number_literal
-
-	# Named identifier.
-	la a0, instruction_la
-	li a1, 2
-	call write_out
-
-	la a0, space
-	li a1, 1
-	call write_out
-
-	la a0, register_a0
-	li a1, 2
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	lw a0, 4(sp)
-	lw a1, 0(sp)
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	j .Lbuild_expression_end
-
-.Lbuild_expression_number_literal:
-	la a0, instruction_li
-	li a1, 2
-	call write_out
-
-	la a0, space
-	li a1, 1
-	call write_out
-
-	la a0, register_a0
-	li a1, 2
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	lw a0, 4(sp)
-	lw a1, 0(sp)
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	j .Lbuild_expression_end
-
-.Lbuild_expression_end:
-	lw a0, 0(sp)
-	add s1, s1, a0
-
-	# Epilogue.
-	lw ra, 12(sp)
-	lw s0, 8(sp)
-	addi sp, sp, 16
-	ret
-
-# Compiles a statement beginning with an identifier.
-.type _compile_identifier, @function
-_compile_identifier:
-	# Prologue.
-	addi sp, sp, -32
-	sw ra, 28(sp)
-	sw s0, 24(sp)
-	addi s0, sp, 32
-
-	# Save the pointer to the identifier and its length on the stack.
-	sw a0, 20(sp)
-	sw a1, 16(sp)
-
-	add s1, s1, a1
-	call _skip_spaces
-	call _read_token
-
-	# Save the pointer and the length of the token following the identifier.
-	sw s1, 12(sp)
-	sw a0, 8(sp)
-
-	add s1, s1, a0 # Skip that token.
-	call _skip_spaces
-
-	lw a0, 12(sp)
-	lw a1, 8(sp)
-	la a2, token_assign
-	call _token_compare
-	beqz a0, .Lcompile_identifier_assign
-
-	lw a0, 12(sp)
-	lw a1, 8(sp)
-	la a2, token_open_paren
-	call _token_compare
-	beqz a0, .Lcompile_identifier_call
-
-	j .Lcompile_identifier_end
-
-.Lcompile_identifier_call:
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call _compile_call
-
-	j .Lcompile_identifier_end
-
-.Lcompile_identifier_assign:
-	call _build_expression
-
-	la a0, instruction_addi
-	li a1, 4
-	call write_out
-
-	la a0, space
-	li a1, 1
-	call write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	la a0, register_a0
-	li a1, 2
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	la a0, digit_zero
-	li a1, 1
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	j .Lcompile_identifier_end
-
-.Lcompile_identifier_end:
-	# Epilogue.
-	lw ra, 28(sp)
-	lw s0, 24(sp)
-	addi sp, sp, 32
-	ret
-
-.type _compile_var, @function
-_compile_var:
-	# Prologue.
-	addi sp, sp, -32
-	sw ra, 28(sp)
-	sw s0, 24(sp)
-	addi s0, sp, 32
-
-	# Variable name.
-	addi s1, s1, 3
-	call _skip_spaces
-	call _read_token
-	sw s1, 20(sp)
-	sw a0, 16(sp)
-	add s1, s1, a0
-
-	# Skip the colon.
-	call _skip_spaces
-	call _read_token
-	add s1, s1, a0
-
-	call _skip_spaces
-	call _read_token
-	sw a0, 12(sp)
-
-	addi a0, s1, 0
-	lw a1, 12(sp)
-	la a2, token_open_square
-	call _token_compare
-	beqz a0, .Lcompile_var_array
-
-	j .Lcompile_var_end
-
-.Lcompile_var_array:
-	call _skip_spaces
-	add s1, s1, 1 # Skip the opening square bracket.
-
-	call _skip_spaces
-	call _read_token
-	sw a0, 8(sp)
-
-	la a0, asm_type
-	li a1, ASM_TYPE_SIZE
-	call write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call write_out
-
-	la a0, asm_object
-	li a1, ASM_OBJECT_SIZE
-	call write_out
-
-	la a0, asm_size
-	li a1, ASM_SIZE_SIZE
-	call write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call write_out
-
-	la a0, comma
-	li a1, 1
-	call write_out
-
-	addi a0, s1, 0
-	lw a1, 8(sp)
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call write_out
-
-	la a0, colon
-	li a1, 1
-	call write_out
-
-	la a0, asm_zero
-	li a1, ASM_ZERO_SIZE
-	call write_out
-
-	addi a0, s1, 0
-	lw a1, 8(sp)
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	la a0, asm_global
-	li a1, ASM_GLOBAL_SIZE
-	call write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call write_out
-
-	la a0, new_line
-	li a1, 1
-	call write_out
-
-	lw a0, 8(sp)
-	add s1, s1, a0
-
-	call _skip_spaces
-	add s1, s1, 1 # Skip the closing square bracket.
-
-	call _skip_spaces
-	call _read_token
-
-	sw a0, 12(sp)
-	j .Lcompile_var_end
-
-.Lcompile_var_end:
-	lw a0, 12(sp)
-	add s1, s1, a0
-
-	# Epilogue.
-	lw ra, 28(sp)
-	lw s0, 24(sp)
-	addi sp, sp, 32
-	ret
-
-.type _handle_token, @function
-_handle_token:
-	# Prologue.
-	addi sp, sp, -32
-	sw ra, 28(sp)
-	sw s0, 24(sp)
-	addi s0, sp, 32
-
-	sw a0, 20(sp)
-
-	# Detect what token has been read.
-	addi a0, s1, 0
-	lw a1, 20(sp)
-	la a2, token_begin
-	call _token_compare
-	beqz a0, .Lhandle_token_begin
-
-	addi a0, s1, 0
-	lw a1, 20(sp)
-	la a2, token_end
-	call _token_compare
-	beqz a0, .Lhandle_token_end
-
-	addi a0, s1, 0
-	lw a1, 20(sp)
-	la a2, token_import
-	call _token_compare
-	beqz a0, .Lhandle_token_import
-
-	addi a0, s1, 0
-	lw a1, 20(sp)
-	la a2, token_var
-	call _token_compare
-	beqz a0, .Lhandle_token_var
-
-	# If the first symbol in the token is a character, assume an identifier.
-	addi a0, s1, 0
-	lb a0, (a0)
-	call is_alpha
-	bnez a0, .Lhandle_token_identifier
-
-	# Ignore the unknown token.
-	lw t0, 20(sp)
-	add s1, s1, t0
-	j .Lhandle_token_return
-
-.Lhandle_token_begin:
-	call _compile_begin
-	j .Lhandle_token_return
-
-.Lhandle_token_end:
-	call _compile_end
-	j .Lhandle_token_return
-
-.Lhandle_token_import:
-	call _compile_import
-	j .Lhandle_token_return
-
-.Lhandle_token_var:
-	call _compile_var
-	j .Lhandle_token_return
-
-.Lhandle_token_identifier:
-	addi a0, s1, 0
-	lw a1, 20(sp)
-	call _compile_identifier
-	j .Lhandle_token_return
-
-.Lhandle_token_return:
-	# Epilogue.
-	lw ra, 28(sp)
-	lw s0, 24(sp)
-	addi sp, sp, 32
-	ret
-
-_start:
-	# Read the source from the standard input.
-	la a0, source_code
-	li a1, SOURCE_BUFFER_SIZE # Buffer size.
-	call read_file
-
-	la s1, source_code # s1 = Source code position.
-	call compile
-
-	# Call exit.
-	li a0, 0   # Use 0 return code.
-	call exit
diff --git a/boot/echo-boot.s b/boot/stage1.s
similarity index 73%
rename from boot/echo-boot.s
rename to boot/stage1.s
index 8256bbd..fbfa16d 100644
--- a/boot/echo-boot.s
+++ b/boot/stage1.s
@@ -1,17 +1,143 @@
-.global _start
+.global _start # Program entry point.
 # s1 - Contains the current position in the source text.
 
+.equ SOURCE_BUFFER_SIZE, 40960
+
 .section .rodata
-SOURCE_BUFFER_SIZE: .long 20480
+section_rodata: .ascii ".section .rodata\n"
+.equ SECTION_RODATA_SIZE, . - section_rodata
+section_text: .ascii ".section .text\n"
+.equ SECTION_TEXT_SIZE, . - section_text
+section_bss: .ascii ".section .bss\n"
+.equ SECTION_BSS_SIZE, . - section_bss
+global_start: .ascii ".global _start\n"
+.equ GLOBAL_START_SIZE, . - global_start
+prologue: .ascii "addi sp, sp, -96\nsw ra, 92(sp)\nsw s0, 88(sp)\naddi s0, sp, 96\n"
+.equ PROLOGUE_SIZE, . - prologue
+epilogue: .ascii "lw ra, 92(sp)\nlw s0, 88(sp)\naddi sp, sp, 96\nret\n"
+.equ EPILOGUE_SIZE, . - epilogue
 
 .section .bss
 .type source_code, @object
-.size source_code, 20480
-source_code: .zero 20480
+.size source_code, SOURCE_BUFFER_SIZE
+source_code: .zero SOURCE_BUFFER_SIZE
 
 .section .text
 
+# Ignores the import.
+.type _compile_import, @function
+_compile_import:
+	# Prologue.
+	addi sp, sp, -8
+	sw ra, 4(sp)
+	sw s0, 0(sp)
+	addi s0, sp, 8
+
+	addi s1, s1, 6
+	call _skip_spaces
+	call _read_token
+	add s1, s1, a0 # Skip the imported module name.
+
+	# Epilogue.
+	lw ra, 4(sp)
+	lw s0, 0(sp)
+	addi sp, sp, 8
+	ret
+
+.type _build_binary_expression, @function
+_build_binary_expression:
+	# Prologue.
+	addi sp, sp, -32
+	sw ra, 28(sp)
+	sw s0, 24(sp)
+	addi s0, sp, 32
+
+	li a0, 0
+	call _build_expression
+
+	call _skip_spaces
+	call _read_token
+	sw a0, 20(sp)
+
+	li t0, 0x26 # &
+	sw t0, 16(sp)
+	mv a0, s1
+	lw a1, 20(sp)
+	addi a2, sp, 16
+	call _token_compare
+	beqz a0, .L_build_binary_expression_and
+
+	li t0, 0x3d # =
+	sw t0, 16(sp)
+	mv a0, s1
+	lw a1, 20(sp)
+	addi a2, sp, 16
+	call _token_compare
+	beqz a0, .L_build_binary_expression_equal
+
+	/* DEBUG
+	mv a0, s1
+	li a1, 8
+	call _write_error */
+
+	j .Lbuild_binary_expression_end
+
+.L_build_binary_expression_equal:
+	addi s1, s1, 1 # Skip =.
+	li a0, 1
+	call _build_expression
+	li t0, 0x0a3161 # a1\n
+	sw t0, 16(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 12(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 8(sp)
+	li t0, 0x20627573 # sub_
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 15
+	call _write_out
+
+	li t0, 0x0a306120 # _a0\n
+	sw t0, 16(sp)
+	li t0, 0x2c306120 # _a0,
+	sw t0, 12(sp)
+	li t0, 0x7a716573 # seqz
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 12
+	call _write_out
+
+	j .Lbuild_binary_expression_end
+
+.L_build_binary_expression_and:
+	addi s1, s1, 1 # Skip &.
+	li a0, 1
+	call _build_expression
+	li t0, 0x0a3161 # a1\n
+	sw t0, 16(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 12(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 8(sp)
+	li t0, 0x20646e61 # and_
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 15
+	call _write_out
+
+	j .Lbuild_binary_expression_end
+
+.Lbuild_binary_expression_end:
+	# Epilogue.
+	lw ra, 28(sp)
+	lw s0, 24(sp)
+	addi sp, sp, 32
+	ret
+
 # Evalutes an expression and saves the result in a0.
+#
+# a0 - X in aX, the register number to save the result.
 .type _build_expression, @function
 _build_expression:
 	# Prologue.
@@ -20,63 +146,120 @@ _build_expression:
 	sw s0, 24(sp)
 	addi s0, sp, 32
 
+	addi a0, a0, '0' # Make the register number to a character.
+	sw a0, 20(sp) # And save it.
+
 	call _skip_spaces
 	call _read_token
-	sw s1, 20(sp)
-	sw a0, 16(sp)
+	sw s1, 16(sp)
+	sw a0, 12(sp)
 
 	# Integer literal.
 	addi a0, s1, 0
-	lb a0, (a0)
+	lbu a0, (a0)
 	call _is_digit
-	bnez a0, .Lbuild_expression_number_literal
+	bnez a0, .Lbuild_expression_literal
+
+	addi a0, s1, 0
+	lbu a0, (a0)
+	li t0, 0x5f # _
+	beq a0, t0, .Lbuild_expression_call
+
+	li t0, 0x61636f6c # loca
+	sw t0, 8(sp)
+	mv a0, s1
+	addi a1, sp, 8
+	li a2, 4
+	call _memcmp
+	beqz a0, .Lbuild_expression_identifier
 
 	# Named identifier.
-	li t0, 0x202c30 # 0,_
-	sw t0, 12(sp)
+	lw t1, 20(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
+	sw t0, 8(sp)
 	li t0, 0x6120616c # la a
-	sw t0, 8(sp)
-	addi a0, sp, 8
+	sw t0, 4(sp)
+	addi a0, sp, 4
 	li a1, 7
 	call _write_out
 
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call _write_out
-
-	li t0, 0x0a # \n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 1
-	call _write_out
-
-	j .Lbuild_expression_end
-
-.Lbuild_expression_number_literal:
-	li t0, 0x202c30 # 0,_
-	sw t0, 12(sp)
-	li t0, 0x6120696c # li a
-	sw t0, 8(sp)
-	addi a0, sp, 8
-	li a1, 7
-	call _write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call _write_out
-
-	li t0, 0x0a # \n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 1
-	call _write_out
-
-	j .Lbuild_expression_end
-
-.Lbuild_expression_end:
 	lw a0, 16(sp)
+	lw a1, 12(sp)
+	call _write_out
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 1
+	call _write_out
+
+	j .Lbuild_expression_advance
+
+.Lbuild_expression_identifier:
+	lw t1, 20(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
+	sw t0, 8(sp)
+	li t0, 0x6120776c # lw a
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 7
+	call _write_out
+
+	lw a0, 16(sp)
+	lw a1, 12(sp)
+	addi a0, a0, 4 # Skip the "loca" variable prefix.
+	addi a1, a1, -4 # Skip the "loca" variable prefix.
+	call _write_out
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	li t0, 0x29707328 # (sp)
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 5
+	call _write_out
+
+	j .Lbuild_expression_advance
+
+.Lbuild_expression_call:
+	lw a0, 16(sp)
+	lw a1, 12(sp)
+	add s1, s1, a1
+	addi s1, s1, 1
+	call _compile_call
+
+	j .Lbuild_expression_end
+
+.Lbuild_expression_literal:
+	lw t1, 20(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
+	sw t0, 8(sp)
+	li t0, 0x6120696c # li a
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 7
+	call _write_out
+
+	lw a0, 16(sp)
+	lw a1, 12(sp)
+	call _write_out
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 1
+	call _write_out
+
+	j .Lbuild_expression_advance
+
+.Lbuild_expression_advance:
+	lw a0, 12(sp)
 	add s1, s1, a0
 
+.Lbuild_expression_end:
 	# Epilogue.
 	lw ra, 28(sp)
 	lw s0, 24(sp)
@@ -120,11 +303,6 @@ _compile_identifier:
 	call _token_compare
 	beqz a0, .Lcompile_identifier_assign
 
-	/* DEBUG
-	mv a0, s1
-	li a1, 4
-	call _write_error */
-
 	lw t0, 12(sp)
 	lbu t0, (t0)
 	li t1, 0x28 # (
@@ -140,7 +318,7 @@ _compile_identifier:
 	j .Lcompile_identifier_end
 
 .Lcompile_identifier_assign:
-	call _build_expression
+	call _build_binary_expression
 
 	li t0, 0x202c30 # 0,_
 	sw t0, 12(sp)
@@ -198,6 +376,7 @@ _compile_call:
 	beq t0, t1, .Lcompile_call_complete
 
 .Lcompile_call_argument:
+	li a0, 0
 	call _build_expression
 
 	li t0, 0x202c30 # 0,_
@@ -210,12 +389,12 @@ _compile_call:
 
 	lw t0, 12(sp) # Argument count for a procedure call.
 
-	# Only 8 arguments are supported with a0-a7.
+	# Only 6 arguments are supported with a0-a5.
 	# Save all arguments on the stack so they aren't overriden afterwards.
 	# The offset on the stack always has two digits in this case.
 	li t1, -4
 	mul t1, t0, t1
-	addi t1, t1, 84
+	addi t1, t1, 60
 	li t2, 10
 	div t3, t1, t2
 	rem t4, t1, t2
@@ -258,10 +437,10 @@ _compile_call:
 	sw zero, 12(sp)
 
 .Lcompile_call_restore:
-	# Just go through all a0-a7 registers and read them from stack.
+	# Just go through all a0-a5 registers and read them from stack.
 	# If this stack value contains garbage, the procedure just shouldn't use it.
 	lw t0, 12(sp)
-	li t1, 7
+	li t1, 5
 	bgt t0, t1, .Lcompile_call_perform
 
 	li t0, 0x6120776c # lw a
@@ -274,7 +453,7 @@ _compile_call:
 
 	li t1, -4
 	mul t1, t0, t1
-	addi t1, t1, 84
+	addi t1, t1, 60
 	li t2, 10
 	div t3, t1, t2
 	rem t4, t1, t2
@@ -367,7 +546,16 @@ _read_token:
 	li t1, ']'
 	beq t0, t1, .Ltoken_character_single
 
-.Ltoken_character_loop_do: # Expect an identifier or a number.
+	li t1, '^'
+	beq t0, t1, .Ltoken_character_single
+
+	li t1, '&'
+	beq t0, t1, .Ltoken_character_single
+
+	li t1, '='
+	beq t0, t1, .Ltoken_character_single
+# Expect an identifier or a number.
+.Ltoken_character_loop_do:
 	lw t6, 4(sp)
 	add t1, s1, t6
 	lbu a0, (t1) # a0 = Current character.
@@ -491,55 +679,33 @@ _compile_assembly:
 .type _compile_program, @function
 _compile_program:
 	# Prologue.
-	addi sp, sp, -32
-	sw ra, 28(sp)
-	sw s0, 24(sp)
-	addi s0, sp, 32
+	addi sp, sp, -8
+	sw ra, 4(sp)
+	sw s0, 0(sp)
+	addi s0, sp, 8
 
-	# .global _start
-	li t0, 0x0a7472 # rt\n
-	sw t0, 20(sp)
-	li t0, 0x6174735f # _sta
-	sw t0, 16(sp)
-	li t0, 0x206c6162 # bal_
-	sw t0, 12(sp)
-	li t0, 0x6f6c672e # .glo
-	sw t0, 8(sp)
-
-	addi a0, sp, 8
-	li a1, 15
+	la a0, global_start
+	li a1, GLOBAL_START_SIZE
 	call _write_out
 
 	addi s1, s1, 8 # program\n.
 
 	# Epilogue.
-	lw ra, 28(sp)
-	lw s0, 24(sp)
-	addi sp, sp, 32
+	lw ra, 4(sp)
+	lw s0, 0(sp)
+	addi sp, sp, 8
 	ret
 
 .type _compile_constant_section, @function
 _compile_constant_section:
 	# Prologue.
-	addi sp, sp, -32
-	sw ra, 28(sp)
-	sw s0, 24(sp)
-	addi s0, sp, 32
+	addi sp, sp, -8
+	sw ra, 4(sp)
+	sw s0, 0(sp)
+	addi s0, sp, 8
 
-	# .section .rodata
-	li t0, 0x0a # \n
-	sw t0, 20(sp)
-	li t0, 0x61746164 # data
-	sw t0, 16(sp)
-	li t0, 0x6f722e20 # _.ro
-	sw t0, 12(sp)
-	li t0, 0x6e6f6974 # tion
-	sw t0, 8(sp)
-	li t0, 0x6365732e # .sec
-	sw t0, 4(sp)
-
-	addi a0, sp, 4
-	li a1, 17
+	la a0, section_rodata
+	li a1, SECTION_RODATA_SIZE
 	call _write_out
 
 	addi s1, s1, 6 # const\n.
@@ -555,9 +721,9 @@ _compile_constant_section:
 
 .Lcompile_constant_section_end:
 	# Epilogue.
-	lw ra, 28(sp)
-	lw s0, 24(sp)
-	addi sp, sp, 32
+	lw ra, 4(sp)
+	lw s0, 0(sp)
+	addi sp, sp, 8
 	ret
 
 .type _compile_constant, @function
@@ -611,23 +777,13 @@ _compile_constant:
 .type _compile_variable_section, @function
 _compile_variable_section:
 	# Prologue.
-	addi sp, sp, -24
-	sw ra, 20(sp)
-	sw s0, 16(sp)
-	addi s0, sp, 24
+	addi sp, sp, -8
+	sw ra, 4(sp)
+	sw s0, 0(sp)
+	addi s0, sp, 8
 
-	# .section .bss
-	li t0, 0x0a73 # s\n
-	sw t0, 12(sp)
-	li t0, 0x73622e20 # _.bs
-	sw t0, 8(sp)
-	li t0, 0x6e6f6974 # tion
-	sw t0, 4(sp)
-	li t0, 0x6365732e # .sec
-	sw t0, 0(sp)
-
-	addi a0, sp, 0
-	li a1, 14
+	la a0, section_bss
+	li a1, SECTION_BSS_SIZE
 	call _write_out
 
 	addi s1, s1, 4 # var\n.
@@ -643,9 +799,9 @@ _compile_variable_section:
 
 .Lcompile_variable_section_end:
 	# Epilogue.
-	lw ra, 20(sp)
-	lw s0, 16(sp)
-	addi sp, sp, 24
+	lw ra, 4(sp)
+	lw s0, 0(sp)
+	addi sp, sp, 8
 	ret
 
 .type _compile_variable, @function
@@ -836,63 +992,61 @@ _compile_procedure:
 	bnez a0, .Lcompile_procedure_begin
 
 	# Generate the procedure prologue with a predefined stack size.
-	li t0, 0x69646461 # addi
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 4
-	call _write_out
-
-	li t0, 0x2c707320 # _sp,
-	sw t0, 12(sp)
-
-	addi a0, sp, 12
-	li a1, 4
-	call _write_out
-
-	addi a0, sp, 12
-	li a1, 4
-	call _write_out
-
-	li t0, 0x0a36392d # -96\n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 4
+	la a0, prologue
+	li a1, PROLOGUE_SIZE
 	call _write_out
 
+	# Save passed arguments on the stack.
 	li t0, 0x0a29 # )\n
 	sw t0, 12(sp)
-	li t0, 0x70732832 # 2(sp
-	sw t0, 8(sp)
-	li t0, 0x39202c61 # a, 9
-	sw t0, 4(sp)
-	li t0, 0x72207773 # sw r
-	sw t0, 0(sp)
-	addi a0, sp, 0
-	li a1, 14
-	call _write_out
-
-	li t0, 0x0a29 # )\n
-	sw t0, 12(sp)
-	li t0, 0x70732838 # 2(sp
+	li t0, 0x70732834 # 4(sp
 	sw t0, 8(sp)
 	li t0, 0x38202c30 # 0, 8
 	sw t0, 4(sp)
-	li t0, 0x73207773 # sw s
+	li t0, 0x61207773 # sw a
 	sw t0, 0(sp)
 	addi a0, sp, 0
 	li a1, 14
 	call _write_out
 
-	li t0, 0x0a363920 # _96\n
-	sw t0, 12(sp)
-	li t0, 0x2c707320 # _sp,
-	sw t0, 8(sp)
-	li t0, 0x2c307320 # _s0,
+	li t0, '0'
+	sb t0, 8(sp)
+	li t0, 0x38202c31 # 1, 8
 	sw t0, 4(sp)
-	li t0, 0x69646461 # addi
-	sw t0, 0(sp)
 	addi a0, sp, 0
-	li a1, 16
+	li a1, 14
+	call _write_out
+
+	li t0, '6'
+	sb t0, 8(sp)
+	li t0, 0x37202c32 # 2, 7
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '2'
+	sb t0, 8(sp)
+	li t0, 0x37202c33 # 3, 7
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '8'
+	sb t0, 8(sp)
+	li t0, 0x36202c34 # 4, 6
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '4'
+	sb t0, 8(sp)
+	li t0, 0x36202c35 # 5, 6
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
 	call _write_out
 
 	# Generate the body of the procedure.
@@ -917,57 +1071,8 @@ _compile_procedure:
 	add s1, s1, 4 # Skip end\n.
 
 	# Generate the procedure epilogue with a predefined stack size.
-	li t0, 0x0a29 # )\n
-	sw t0, 12(sp)
-	li t0, 0x70732832 # 2(sp
-	sw t0, 8(sp)
-	li t0, 0x39202c61 # a, 9
-	sw t0, 4(sp)
-	li t0, 0x7220776c # lw r
-	sw t0, 0(sp)
-	addi a0, sp, 0
-	li a1, 14
-	call _write_out
-
-	li t0, 0x0a29 # )\n
-	sw t0, 12(sp)
-	li t0, 0x70732838 # 2(sp
-	sw t0, 8(sp)
-	li t0, 0x38202c30 # 0, 8
-	sw t0, 4(sp)
-	li t0, 0x7320776c # lw s
-	sw t0, 0(sp)
-	addi a0, sp, 0
-	li a1, 14
-	call _write_out
-
-	li t0, 0x69646461 # addi
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 4
-	call _write_out
-
-	li t0, 0x2c707320 # _sp,
-	sw t0, 12(sp)
-
-	addi a0, sp, 12
-	li a1, 4
-	call _write_out
-
-	addi a0, sp, 12
-	li a1, 4
-	call _write_out
-
-	li t0, 0x0a3639 # 96\n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 3
-	call _write_out
-
-	li t0, 0x0a746572 # ret\n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 4
+	la a0, epilogue
+	li a1, EPILOGUE_SIZE
 	call _write_out
 
 	# Epilogue.
@@ -1018,8 +1123,100 @@ _token_compare:
 .Ltoken_compare_end:
 	ret
 
+.type _compile_goto, @function
+_compile_goto:
+	# Prologue.
+	addi sp, sp, -16
+	sw ra, 12(sp)
+	sw s0, 8(sp)
+	addi s0, sp, 16
+
+	addi s1, s1, 4 # Skip the goto keyword.
+
+	li t0, 0x206a # j_
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 2
+	call _write_out
+
+	call _skip_spaces
+	sw s1, 8(sp) # We should be on dot the label is beginning with.
+	addi s1, s1, 1
+
+	call _read_token
+	add s1, s1, a0
+	addi a1, a0, 1 # Label length and the dot.
+	lw a0, 8(sp) # Saved dot position.
+	call _write_out
+
+	addi s1, s1, 1 # Skip the new line.
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 1
+	call _write_out
+
+	# Epilogue.
+	lw ra, 12(sp)
+	lw s0, 8(sp)
+	addi sp, sp, 16
+	ret
+
+# a0 - Line length.
+.type _compile_label, @function
+_compile_label:
+	# Prologue.
+	addi sp, sp, -16
+	sw ra, 12(sp)
+	sw s0, 8(sp)
+	addi s0, sp, 16
+
+	sw a0, 0(sp) # Save the line length.
+
+	# Write the whole line as is.
+	mv a0, s1
+	lw a1, 0(sp)
+	call _write_out
+
+	lw t0, 0(sp) # Line length.
+	mv t1, s1 # Line start.
+
+	add t1, t1, t0
+	addi t1, t1, -1 # Last character on the line.
+
+	lbu t1, (t1)
+	li t2, ':'
+	beq t1, t2, .Lcompile_label_colon
+
+	li t0, 0x3a # :
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 1
+	call _write_out
+
+.Lcompile_label_colon:
+	li t0, 0x0a # \n
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 1
+	call _write_out
+
+	lw a0, 0(sp)
+	addi a0, a0, 1 # Skip the new line as well.
+	add s1, s1, a0 # Skip the line.
+
+	# Epilogue.
+	lw ra, 12(sp)
+	lw s0, 8(sp)
+	addi sp, sp, 16
+	ret
+
 # Parameters:
 # a0 - Line length.
+# a1 - Whether the section header was already emitted. If not it should be
+# emitted before any code is written.
+#
 # Returns 1 in a0 if the parsed line contained a text section element such a
 # procedure or the program entry point. Otherwise sets a0 to 0.
 .type _compile_line, @function
@@ -1030,7 +1227,9 @@ _compile_line:
 	sw s0, 24(sp)
 	addi s0, sp, 32
 
-	sw a0, 20(sp) # a0 - Line length.
+	# Preserve passed arguments.
+	sw a0, 20(sp)
+	sw a1, 16(sp)
 
 	beqz a0, .Lcompile_line_empty # Skip an empty line.
 
@@ -1039,75 +1238,108 @@ _compile_line:
 	beq t0, t1, .Lcompile_line_comment
 
 	li t0, 0x0a6d6172 # ram\n
-	sw t0, 16(sp)
-	li t0, 0x676f7270 # prog
 	sw t0, 12(sp)
+	li t0, 0x676f7270 # prog
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 8
 	call _memcmp
 	beqz a0, .Lcompile_line_program
 
 	li t0, 0x0a74 # t\n
-	sw t0, 16(sp)
-	li t0, 0x736e6f63 # cons
 	sw t0, 12(sp)
+	li t0, 0x736e6f63 # cons
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 6
 	call _memcmp
 	beqz a0, .Lcompile_line_const
 
 	li t0, 0x0a726176 # var\n
-	sw t0, 16(sp)
+	sw t0, 12(sp)
 	mv a0, s1
-	addi a1, sp, 16
+	addi a1, sp, 12
 	li a2, 4
 	call _memcmp
 	beqz a0, .Lcompile_line_var
 
 	li t0, 0x20 # _
-	sw t0, 16(sp)
-	li t0, 0x636f7270 # proc
 	sw t0, 12(sp)
+	li t0, 0x636f7270 # proc
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 5
 	call _memcmp
 	beqz a0, .Lcompile_line_procedure
 
 	li t0, 0x0a6e # n\n
-	sw t0, 16(sp)
-	li t0, 0x69676562 # begi
 	sw t0, 12(sp)
+	li t0, 0x69676562 # begi
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 6
 	call _memcmp
 	beqz a0, .Lcompile_line_begin
 
 	li t0, 0x2e646e65 # end.
-	sw t0, 16(sp)
+	sw t0, 12(sp)
 	mv a0, s1
-	addi a1, sp, 16
+	addi a1, sp, 12
 	li a2, 4
 	call _memcmp
 	beqz a0, .Lcompile_line_exit
 
 	li t0, 0x61636f6c # loca
-	sw t0, 16(sp)
+	sw t0, 12(sp)
 	mv a0, s1
-	addi a1, sp, 16
+	addi a1, sp, 12
 	li a2, 4
 	call _memcmp
 	beqz a0, .Lcompile_line_identifier
 
+	li t0, 0x7472 # rt
+	sw t0, 12(sp)
+	li t0, 0x6f706d69 # impo
+	sw t0, 8(sp)
+	mv a0, s1
+	addi a1, sp, 8
+	li a2, 6
+	call _memcmp
+	beqz a0, .Lcompile_line_import
+
+	li t0, 0x6f746f67 # goto
+	sw t0, 12(sp)
+	mv a0, s1
+	addi a1, sp, 12
+	li a2, 4
+	call _memcmp
+	beqz a0, .Lcompile_line_goto
+
 	lbu t0, (s1)
+	li t1, '.'
+	beq t0, t1, .Lcompile_line_label
 	li t1, '_'
 	beq t0, t1, .Lcompile_line_identifier
 
 	j .Lcompile_line_unchanged # Else.
 
+.Lcompile_line_label:
+	lw a0, 20(sp)
+	call _compile_label
+	j .Lcompile_line_section
+
+.Lcompile_line_goto:
+	call _compile_goto
+	j .Lcompile_line_section
+
+.Lcompile_line_import:
+	call _compile_import
+	j .Lcompile_line_section
+
 .Lcompile_line_identifier:
 	call _compile_identifier
 	j .Lcompile_line_section
@@ -1117,6 +1349,10 @@ _compile_line:
 	j .Lcompile_line_section
 
 .Lcompile_line_begin:
+	lw a1, 16(sp)
+	bnez a1, .Lcompile_line_compile_entry
+	call _compile_text_section
+.Lcompile_line_compile_entry:
 	call _compile_entry_point
 	li a0, 1
 	j .Lcompile_line_end
@@ -1126,6 +1362,10 @@ _compile_line:
 	j .Lcompile_line_section
 
 .Lcompile_line_procedure:
+	lw a1, 16(sp)
+	bnez a1, .Lcompile_line_compile_procedure
+	call _compile_text_section
+.Lcompile_line_compile_procedure:
 	call _compile_procedure
 	li a0, 1
 	j .Lcompile_line_end
@@ -1162,6 +1402,7 @@ _compile_line:
 	addi sp, sp, 32
 	ret
 
+# Prints ".section .text" and exits.
 .type _compile_text_section, @function
 _compile_text_section:
 	# Prologue.
@@ -1170,18 +1411,8 @@ _compile_text_section:
 	sw s0, 16(sp)
 	addi s0, sp, 24
 
-	# .section .text
-	li t0, 0x0a7478 # xt\n
-	sw t0, 12(sp)
-	li t0, 0x65742e20 # _.te
-	sw t0, 8(sp)
-	li t0, 0x6e6f6974 # tion
-	sw t0, 4(sp)
-	li t0, 0x6365732e # .sec
-	sw t0, 0(sp)
-
-	addi a0, sp, 0
-	li a1, 15
+	la a0, section_text
+	li a1, SECTION_TEXT_SIZE
 	call _write_out
 
 	# Epilogue.
@@ -1291,14 +1522,23 @@ _compile:
 	sw s0, 8(sp)
 	addi s0, sp, 16
 
+	sw zero, 4(sp) # Whether the text section header was already emitted.
+
 .Lcompile_do:
 	lbu t0, (s1) # t0 = Current character.
 	beqz t0, .Lcompile_end # Exit the loop on the NUL character.
 
 	call _skip_indentation
 	call _read_line
+	lw a1, 4(sp)
 	call _compile_line
 
+	beqz a0, .Lcompile_do
+	# Update whether the text section header was already emitted.
+	lw t0, 4(sp)
+	or t0, t0, a0
+	sw t0, 4(sp)
+
 	j .Lcompile_do
 .Lcompile_end:
 
@@ -1313,8 +1553,7 @@ _compile:
 _start:
 	# Read the source from the standard input.
 	la a0, source_code
-	la a1, SOURCE_BUFFER_SIZE # Buffer size.
-	lw a1, (a1)
+	li a1, SOURCE_BUFFER_SIZE # Buffer size.
 	call _read_file
 
 	la s1, source_code # s1 = Source code position.
diff --git a/boot/stage2.elna b/boot/stage2.elna
index e37b3e6..4e87e89 100644
--- a/boot/stage2.elna
+++ b/boot/stage2.elna
@@ -1,73 +1,221 @@
 program
 # s1 - Contains the current position in the source text.
 
+import dummy
+
 const
-	SOURCE_BUFFER_SIZE := 20480
+	SOURCE_BUFFER_SIZE := 40960
 
 var
-	source_code: [20480]Byte
+	source_code: [40960]Byte
 
-.section .text
-
-# Evalutes an expression and saves the result in a0.
-proc _build_expression()
+# Ignores the import.
+proc _compile_import()
+var loca0: Word
 begin
+	_advance(6)
+	_skip_spaces()
+	loca0 := _read_token()
+	_advance(loca0) # Skip the imported module name.
+end
+
+proc _build_binary_expression()
+begin
+	_build_expression(0)
+
 	_skip_spaces()
 	call _read_token
-	sw s1, 20(sp)
-	sw a0, 16(sp)
+	sw a0, 20(sp)
+
+	li t0, 0x26 # &
+	sw t0, 16(sp)
+	mv a0, s1
+	lw a1, 20(sp)
+	addi a2, sp, 16
+	call _token_compare
+	beqz a0, .L_build_binary_expression_and
+
+	li t0, 0x3d # =
+	sw t0, 16(sp)
+	mv a0, s1
+	lw a1, 20(sp)
+	addi a2, sp, 16
+	call _token_compare
+	beqz a0, .L_build_binary_expression_equal
+
+	/* DEBUG
+	mv a0, s1
+	li a1, 8
+	call _write_error */
+
+	j .Lbuild_binary_expression_end
+
+.L_build_binary_expression_equal:
+	addi s1, s1, 1 # Skip =.
+	_build_expression(1)
+	li t0, 0x0a3161 # a1\n
+	sw t0, 16(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 12(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 8(sp)
+	li t0, 0x20627573 # sub_
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 15
+	call _write_out
+
+	li t0, 0x0a306120 # _a0\n
+	sw t0, 16(sp)
+	li t0, 0x2c306120 # _a0,
+	sw t0, 12(sp)
+	li t0, 0x7a716573 # seqz
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 12
+	call _write_out
+
+	j .Lbuild_binary_expression_end
+
+.L_build_binary_expression_and:
+	addi s1, s1, 1 # Skip &.
+	_build_expression(1)
+	li t0, 0x0a3161 # a1\n
+	sw t0, 16(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 12(sp)
+	li t0, 0x202c3061 # a0,_
+	sw t0, 8(sp)
+	li t0, 0x20646e61 # and_
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 15
+	call _write_out
+
+	j .Lbuild_binary_expression_end
+
+.Lbuild_binary_expression_end:
+end
+
+# Evalutes an expression and saves the result in a0.
+#
+# a0 - X in aX, the register number to save the result.
+proc _build_expression()
+begin
+	addi a0, a0, '0' # Make the register number to a character.
+	sw a0, 20(sp) # And save it.
+
+	_skip_spaces()
+	call _read_token
+	sw s1, 16(sp)
+	sw a0, 12(sp)
 
 	# Integer literal.
 	addi a0, s1, 0
-	lb a0, (a0)
+	lbu a0, (a0)
 	call _is_digit
-	bnez a0, .Lbuild_expression_number_literal
+	bnez a0, .Lbuild_expression_literal
+
+	addi a0, s1, 0
+	lbu a0, (a0)
+	li t0, 0x5f # _
+	beq a0, t0, .Lbuild_expression_call
+
+	li t0, 0x61636f6c # loca
+	sw t0, 8(sp)
+	mv a0, s1
+	addi a1, sp, 8
+	li a2, 4
+	call _memcmp
+	beqz a0, .Lbuild_expression_identifier
 
 	# Named identifier.
-	li t0, 0x202c30 # 0,_
-	sw t0, 12(sp)
+	lw t1, 20(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
+	sw t0, 8(sp)
 	li t0, 0x6120616c # la a
-	sw t0, 8(sp)
-	addi a0, sp, 8
+	sw t0, 4(sp)
+	addi a0, sp, 4
 	li a1, 7
 	call _write_out
 
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call _write_out
-
-	li t0, 0x0a # \n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 1
-	call _write_out
-
-	j .Lbuild_expression_end
-
-.Lbuild_expression_number_literal:
-	li t0, 0x202c30 # 0,_
-	sw t0, 12(sp)
-	li t0, 0x6120696c # li a
-	sw t0, 8(sp)
-	addi a0, sp, 8
-	li a1, 7
-	call _write_out
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call _write_out
-
-	li t0, 0x0a # \n
-	sw t0, 12(sp)
-	addi a0, sp, 12
-	li a1, 1
-	call _write_out
-
-	j .Lbuild_expression_end
-
-.Lbuild_expression_end:
 	lw a0, 16(sp)
+	lw a1, 12(sp)
+	call _write_out
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 1
+	call _write_out
+
+	goto .Lbuild_expression_advance
+
+	.Lbuild_expression_identifier
+	lw t1, 20(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
+	sw t0, 8(sp)
+	li t0, 0x6120776c # lw a
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 7
+	call _write_out
+
+	lw a0, 16(sp)
+	lw a1, 12(sp)
+	addi a0, a0, 4 # Skip the "loca" variable prefix.
+	addi a1, a1, -4 # Skip the "loca" variable prefix.
+	call _write_out
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	li t0, 0x29707328 # (sp)
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 5
+	call _write_out
+
+	goto .Lbuild_expression_advance
+
+	.Lbuild_expression_call
+	lw a0, 16(sp)
+	lw a1, 12(sp)
+	add s1, s1, a1
+	addi s1, s1, 1
+	call _compile_call
+
+	goto .Lbuild_expression_end
+
+	.Lbuild_expression_literal
+	lw t1, 20(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
+	sw t0, 8(sp)
+	li t0, 0x6120696c # li a
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 7
+	call _write_out
+
+	lw a0, 16(sp)
+	lw a1, 12(sp)
+	call _write_out
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 1
+	call _write_out
+
+	goto .Lbuild_expression_advance
+
+	.Lbuild_expression_advance
+	lw a0, 12(sp)
 	add s1, s1, a0
+
+	.Lbuild_expression_end
 end
 
 # Compiles a statement beginning with an identifier.
@@ -101,27 +249,22 @@ begin
 	call _token_compare
 	beqz a0, .Lcompile_identifier_assign
 
-	/* DEBUG
-	mv a0, s1
-	li a1, 4
-	call _write_error */
-
 	lw t0, 12(sp)
 	lbu t0, (t0)
 	li t1, 0x28 # (
 	beq t0, t1, .Lcompile_identifier_call
 
-	j .Lcompile_identifier_end
+	goto .Lcompile_identifier_end
 
-.Lcompile_identifier_call:
+	.Lcompile_identifier_call
 	lw a0, 20(sp)
 	lw a1, 16(sp)
 	call _compile_call
 
-	j .Lcompile_identifier_end
+	goto .Lcompile_identifier_end
 
-.Lcompile_identifier_assign:
-	call _build_expression
+	.Lcompile_identifier_assign
+	_build_binary_expression()
 
 	li t0, 0x202c30 # 0,_
 	sw t0, 12(sp)
@@ -145,9 +288,9 @@ begin
 	li a1, 5
 	call _write_out
 
-	j .Lcompile_identifier_end
+	goto .Lcompile_identifier_end
 
-.Lcompile_identifier_end:
+	.Lcompile_identifier_end
 end
 
 # Compiles a procedure call. Expects s1 to point to the first argument.
@@ -161,15 +304,15 @@ begin
 	sw a1, 16(sp)
 	sw zero, 12(sp) # Argument count for a procedure call.
 
-.Lcompile_call_paren:
+	.Lcompile_call_paren
 	_skip_spaces()
 	call _read_token
 	lbu t0, (s1)
 	li t1, 0x29 # )
 	beq t0, t1, .Lcompile_call_complete
 
-.Lcompile_call_argument:
-	call _build_expression
+	.Lcompile_call_argument
+	_build_expression(0)
 
 	li t0, 0x202c30 # 0,_
 	sw t0, 8(sp)
@@ -181,12 +324,12 @@ begin
 
 	lw t0, 12(sp) # Argument count for a procedure call.
 
-	# Only 8 arguments are supported with a0-a7.
+	# Only 6 arguments are supported with a0-a5.
 	# Save all arguments on the stack so they aren't overriden afterwards.
 	# The offset on the stack always has two digits in this case.
 	li t1, -4
 	mul t1, t0, t1
-	addi t1, t1, 84
+	addi t1, t1, 60
 	li t2, 10
 	div t3, t1, t2
 	rem t4, t1, t2
@@ -223,16 +366,16 @@ begin
 	sw t0, 12(sp)
 
 	_advance(1) # Skip the comma between the arguments.
-	j .Lcompile_call_argument
+	goto .Lcompile_call_argument
 
-.Lcompile_call_complete:
+	.Lcompile_call_complete
 	sw zero, 12(sp)
 
-.Lcompile_call_restore:
-	# Just go through all a0-a7 registers and read them from stack.
+	.Lcompile_call_restore
+	# Just go through all a0-a5 registers and read them from stack.
 	# If this stack value contains garbage, the procedure just shouldn't use it.
 	lw t0, 12(sp)
-	li t1, 7
+	li t1, 5
 	bgt t0, t1, .Lcompile_call_perform
 
 	li t0, 0x6120776c # lw a
@@ -245,7 +388,7 @@ begin
 
 	li t1, -4
 	mul t1, t0, t1
-	addi t1, t1, 84
+	addi t1, t1, 60
 	li t2, 10
 	div t3, t1, t2
 	rem t4, t1, t2
@@ -271,9 +414,9 @@ begin
 	addi t0, t0, 1
 	sw t0, 12(sp)
 
-	j .Lcompile_call_restore
+	goto .Lcompile_call_restore
 
-.Lcompile_call_perform:
+	.Lcompile_call_perform
 	li t0, 0x20
 	sw t0, 8(sp)
 	li t0, 0x6c6c6163
@@ -327,7 +470,16 @@ begin
 	li t1, ']'
 	beq t0, t1, .Ltoken_character_single
 
-.Ltoken_character_loop_do: # Expect an identifier or a number.
+	li t1, '^'
+	beq t0, t1, .Ltoken_character_single
+
+	li t1, '&'
+	beq t0, t1, .Ltoken_character_single
+
+	li t1, '='
+	beq t0, t1, .Ltoken_character_single
+	# Expect an identifier or a number.
+	.Ltoken_character_loop_do
 	lw t6, 4(sp)
 	add t1, s1, t6
 	lbu a0, (t1) # a0 = Current character.
@@ -338,15 +490,15 @@ begin
 	lw t6, 4(sp)
 	addi t6, t6, 1
 	sw t6, 4(sp)
-	j .Ltoken_character_loop_do
+	goto .Ltoken_character_loop_do
 
-.Ltoken_character_single:
+	.Ltoken_character_single
 	lw t6, 4(sp)
 	addi t6, t6, 1
 	sw t6, 4(sp)
-	j .Ltoken_character_end
+	goto .Ltoken_character_end
 
-.Ltoken_character_colon:
+	.Ltoken_character_colon
 	lbu t0, 1(s1) # t0 = The character after the colon.
 	lw t6, 4(sp)
 	addi t6, t6, 1
@@ -354,16 +506,16 @@ begin
 
 	li t1, '='
 	beq t0, t1, .Ltoken_character_single
-	j .Ltoken_character_end
+	goto .Ltoken_character_end
 
-.Ltoken_character_end:
+	.Ltoken_character_end
 	lw a0, 4(sp)
 end
 
 # Skips the spaces till the next non space character.
 proc _skip_spaces()
 begin
-.Lspace_loop_do:
+	.Lspace_loop_do
 	lbu t0, (s1) # t0 = Current character.
 
 	li t1, ' '
@@ -375,53 +527,50 @@ begin
 	li t1, '\r'
 	beq t0, t1, .Lspace_loop_repeat
 
-	j .Lspace_loop_end
-.Lspace_loop_repeat:
+	goto .Lspace_loop_end
+	.Lspace_loop_repeat
 	_advance(1)
-	j .Lspace_loop_do
+	goto .Lspace_loop_do
 
-.Lspace_loop_end:
+	.Lspace_loop_end
 end
 
 # Skips tabs at the line beginning.
 proc _skip_indentation()
 begin
-.Lskip_indentation_do:
+	.Lskip_indentation_do
 	lbu t0, (s1)
 
 	li t1, '\t'
 	beq t0, t1, .Lskip_indentation_skip
 
-	j .Lskip_indentation_end
+	goto .Lskip_indentation_end
 
-.Lskip_indentation_skip:
+	.Lskip_indentation_skip
 	_advance(1)
-	j .Lskip_indentation_do
+	goto .Lskip_indentation_do
 
-.Lskip_indentation_end:
+	.Lskip_indentation_end
 end
 
 # Parameters:
 # a0 - Line length.
-proc _skip_comment()
+proc _skip_comment(loca84: Word)
 begin
-	add s1, s1, a0
+	_advance(loca84)
 	_advance(1) # Skip the new line.
 end
 
 # Parameters:
 # a0 - Line length.
-proc _compile_assembly()
+proc _compile_assembly(loca84: Word)
+var loca0: ^Byte
 begin
-	sw a0, 4(sp) # a0 - Line length.
-
 	# Write the source to the standard output.
-	mv a0, s1
-	lw a1, 4(sp)
-	call _write_out
+	loca0 := _current()
 
-	lw t0, 4(sp)
-	add s1, s1, t0
+	_write_out(loca0, loca84)
+	_advance(loca84)
 
 	li t0, '\n'
 	sb t0, 0(sp)
@@ -471,16 +620,16 @@ begin
 
 	_advance(6) # const\n.
 
-.Lcompile_constant_section_item:
+	.Lcompile_constant_section_item
 	_skip_spaces()
 	lbu a0, (s1)
 	call _is_upper
 	beqz a0, .Lcompile_constant_section_end
 
-	call _compile_constant
-	j .Lcompile_constant_section_item
+	_compile_constant()
+	goto .Lcompile_constant_section_item
 
-.Lcompile_constant_section_end:
+	.Lcompile_constant_section_end
 end
 
 proc _compile_constant()
@@ -538,16 +687,16 @@ begin
 
 	_advance(4) # var\n.
 
-.Lcompile_variable_section_item:
+	.Lcompile_variable_section_item
 	_skip_spaces()
 	lbu a0, (s1)
 	call _is_lower
 	beqz a0, .Lcompile_variable_section_end
 
-	call _compile_variable
-	j .Lcompile_variable_section_item
+	_compile_variable()
+	goto .Lcompile_variable_section_item
 
-.Lcompile_variable_section_end:
+	.Lcompile_variable_section_end
 end
 
 proc _compile_variable()
@@ -708,7 +857,7 @@ begin
 
 	# Skip all declarations until we find the "begin" keyword, denoting the
 	# beginning of the procedure body.
-.Lcompile_procedure_begin:
+	.Lcompile_procedure_begin
 	_skip_spaces()
 	call _read_token
 
@@ -758,7 +907,7 @@ begin
 
 	li t0, 0x0a29 # )\n
 	sw t0, 12(sp)
-	li t0, 0x70732838 # 2(sp
+	li t0, 0x70732838 # 8(sp
 	sw t0, 8(sp)
 	li t0, 0x38202c30 # 0, 8
 	sw t0, 4(sp)
@@ -780,8 +929,61 @@ begin
 	li a1, 16
 	call _write_out
 
+	# Save passed arguments on the stack.
+	li t0, 0x0a29 # )\n
+	sw t0, 12(sp)
+	li t0, 0x70732834 # 4(sp
+	sw t0, 8(sp)
+	li t0, 0x38202c30 # 0, 8
+	sw t0, 4(sp)
+	li t0, 0x61207773 # sw a
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '0'
+	sb t0, 8(sp)
+	li t0, 0x38202c31 # 1, 8
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '6'
+	sb t0, 8(sp)
+	li t0, 0x37202c32 # 2, 7
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '2'
+	sb t0, 8(sp)
+	li t0, 0x37202c33 # 3, 7
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '8'
+	sb t0, 8(sp)
+	li t0, 0x36202c34 # 4, 6
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
+	li t0, '4'
+	sb t0, 8(sp)
+	li t0, 0x36202c35 # 5, 6
+	sw t0, 4(sp)
+	addi a0, sp, 0
+	li a1, 14
+	call _write_out
+
 	# Generate the body of the procedure.
-.Lcompile_procedure_body:
+	.Lcompile_procedure_body
 	_skip_indentation()
 	call _read_line
 	sw a0, 12(sp)
@@ -796,9 +998,9 @@ begin
 
 	lw a0, 12(sp)
 	call _compile_line
-	j .Lcompile_procedure_body
+	goto .Lcompile_procedure_body
 
-.Lcompile_procedure_end:
+	.Lcompile_procedure_end
 	add s1, s1, 4 # Skip end\n.
 
 	# Generate the procedure epilogue with a predefined stack size.
@@ -816,7 +1018,7 @@ begin
 
 	li t0, 0x0a29 # )\n
 	sw t0, 12(sp)
-	li t0, 0x70732838 # 2(sp
+	li t0, 0x70732838 # 8(sp
 	sw t0, 8(sp)
 	li t0, 0x38202c30 # 0, 8
 	sw t0, 4(sp)
@@ -869,7 +1071,7 @@ begin
 	addi t1, a1, 0
 	addi t2, a2, 0
 
-.Ltoken_compare_loop:
+	.Ltoken_compare_loop
 	lbu t3, (t2)
 
 	# Will only be 0 if the current character in the null terminated string is \0 and the remaining length of the
@@ -886,25 +1088,97 @@ begin
 	addi t0, t0, 1
 	addi t1, t1, -1
 	addi t2, t2, 1
-	j .Ltoken_compare_loop
+	goto .Ltoken_compare_loop
 
-.Ltoken_compare_not_equal:
+	.Ltoken_compare_not_equal
 	li a0, 1
-	j .Ltoken_compare_end
+	goto .Ltoken_compare_end
 
-.Ltoken_compare_equal:
+	.Ltoken_compare_equal
 	li a0, 0
 
-.Ltoken_compare_end:
+	.Ltoken_compare_end
+end
+
+proc _compile_goto()
+begin
+	addi s1, s1, 4 # Skip the goto keyword.
+
+	li t0, 0x206a # j_
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 2
+	call _write_out
+
+	_skip_spaces()
+	sw s1, 8(sp) # We should be on dot the label is beginning with.
+	_advance(1)
+
+	call _read_token
+	add s1, s1, a0
+	addi a1, a0, 1 # Label length and the dot.
+	lw a0, 8(sp) # Saved dot position.
+	call _write_out
+
+	_advance(1) # Skip the new line.
+
+	li t0, 0x0a # \n
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 1
+	call _write_out
+end
+
+# a0 - Line length.
+proc _compile_label()
+begin
+	sw a0, 0(sp) # Save the line length.
+
+	# Write the whole line as is.
+	mv a0, s1
+	lw a1, 0(sp)
+	call _write_out
+
+	lw t0, 0(sp) # Line length.
+	mv t1, s1 # Line start.
+
+	add t1, t1, t0
+	addi t1, t1, -1 # Last character on the line.
+
+	lbu t1, (t1)
+	li t2, ':'
+	beq t1, t2, .Lcompile_label_colon
+
+	li t0, 0x3a # :
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 1
+	call _write_out
+
+	.Lcompile_label_colon
+	li t0, 0x0a # \n
+	sw t0, 4(sp)
+	addi a0, sp, 4
+	li a1, 1
+	call _write_out
+
+	lw a0, 0(sp)
+	addi a0, a0, 1 # Skip the new line as well.
+	add s1, s1, a0 # Skip the line.
 end
 
 # Parameters:
 # a0 - Line length.
+# a1 - Whether the section header was already emitted. If not it should be
+# emitted before any code is written.
+#
 # Returns 1 in a0 if the parsed line contained a text section element such a
 # procedure or the program entry point. Otherwise sets a0 to 0.
 proc _compile_line()
 begin
-	sw a0, 20(sp) # a0 - Line length.
+	# Preserve passed arguments.
+	sw a0, 20(sp)
+	sw a1, 16(sp)
 
 	beqz a0, .Lcompile_line_empty # Skip an empty line.
 
@@ -913,125 +1187,167 @@ begin
 	beq t0, t1, .Lcompile_line_comment
 
 	li t0, 0x0a6d6172 # ram\n
-	sw t0, 16(sp)
-	li t0, 0x676f7270 # prog
 	sw t0, 12(sp)
+	li t0, 0x676f7270 # prog
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 8
 	call _memcmp
 	beqz a0, .Lcompile_line_program
 
 	li t0, 0x0a74 # t\n
-	sw t0, 16(sp)
-	li t0, 0x736e6f63 # cons
 	sw t0, 12(sp)
+	li t0, 0x736e6f63 # cons
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 6
 	call _memcmp
 	beqz a0, .Lcompile_line_const
 
 	li t0, 0x0a726176 # var\n
-	sw t0, 16(sp)
-	mv a0, s1
-	addi a1, sp, 16
-	li a2, 4
-	call _memcmp;
-	beqz a0, .Lcompile_line_var
-
-	li t0, 0x20 # _
-	sw t0, 16(sp)
-	li t0, 0x636f7270 # proc
 	sw t0, 12(sp)
 	mv a0, s1
 	addi a1, sp, 12
+	li a2, 4
+	call _memcmp
+	beqz a0, .Lcompile_line_var
+
+	li t0, 0x20 # _
+	sw t0, 12(sp)
+	li t0, 0x636f7270 # proc
+	sw t0, 8(sp)
+	mv a0, s1
+	addi a1, sp, 8
 	li a2, 5
 	call _memcmp
 	beqz a0, .Lcompile_line_procedure
 
 	li t0, 0x0a6e # n\n
-	sw t0, 16(sp)
-	li t0, 0x69676562 # begi
 	sw t0, 12(sp)
+	li t0, 0x69676562 # begi
+	sw t0, 8(sp)
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 8
 	li a2, 6
 	call _memcmp
 	beqz a0, .Lcompile_line_begin
 
 	li t0, 0x2e646e65 # end.
-	sw t0, 16(sp)
+	sw t0, 12(sp)
 	mv a0, s1
-	addi a1, sp, 16
+	addi a1, sp, 12
 	li a2, 4
 	call _memcmp
 	beqz a0, .Lcompile_line_exit
 
 	li t0, 0x61636f6c # loca
-	sw t0, 16(sp)
+	sw t0, 12(sp)
 	mv a0, s1
-	addi a1, sp, 16
+	addi a1, sp, 12
 	li a2, 4
 	call _memcmp
 	beqz a0, .Lcompile_line_identifier
 
+	li t0, 0x7472 # rt
+	sw t0, 12(sp)
+	li t0, 0x6f706d69 # impo
+	sw t0, 8(sp)
+	mv a0, s1
+	addi a1, sp, 8
+	li a2, 6
+	call _memcmp
+	beqz a0, .Lcompile_line_import
+
+	li t0, 0x6f746f67 # goto
+	sw t0, 12(sp)
+	mv a0, s1
+	addi a1, sp, 12
+	li a2, 4
+	call _memcmp
+	beqz a0, .Lcompile_line_goto
+
 	lbu t0, (s1)
+	li t1, '.'
+	beq t0, t1, .Lcompile_line_label
 	li t1, '_'
 	beq t0, t1, .Lcompile_line_identifier
 
-	j .Lcompile_line_unchanged # Else.
+	goto .Lcompile_line_unchanged # Else.
 
-.Lcompile_line_identifier:
-	call _compile_identifier
-	j .Lcompile_line_section
+	.Lcompile_line_label
+	lw a0, 20(sp)
+	call _compile_label
+	goto .Lcompile_line_section
 
-.Lcompile_line_exit:
-	call _compile_exit
-	j .Lcompile_line_section
+	.Lcompile_line_goto
+	_compile_goto()
+	goto .Lcompile_line_section
 
-.Lcompile_line_begin:
-	call _compile_entry_point
+	.Lcompile_line_import
+	_compile_import()
+	goto .Lcompile_line_section
+
+	.Lcompile_line_identifier
+	_compile_identifier()
+	goto .Lcompile_line_section
+
+	.Lcompile_line_exit
+	_compile_exit()
+	goto .Lcompile_line_section
+
+	.Lcompile_line_begin
+	lw a1, 16(sp)
+	bnez a1, .Lcompile_line_compile_entry
+	_compile_text_section()
+	.Lcompile_line_compile_entry
+	_compile_entry_point()
 	li a0, 1
-	j .Lcompile_line_end
+	goto .Lcompile_line_end
 
-.Lcompile_line_const:
-	call _compile_constant_section
-	j .Lcompile_line_section
+	.Lcompile_line_const
+	_compile_constant_section()
+	goto .Lcompile_line_section
 
-.Lcompile_line_procedure:
-	call _compile_procedure
+	.Lcompile_line_procedure
+	lw a1, 16(sp)
+	bnez a1, .Lcompile_line_compile_procedure
+	_compile_text_section()
+	.Lcompile_line_compile_procedure
+	_compile_procedure()
 	li a0, 1
-	j .Lcompile_line_end
+	goto .Lcompile_line_end
 
-.Lcompile_line_var:
-	call _compile_variable_section
-	j .Lcompile_line_section
+	.Lcompile_line_var
+	_compile_variable_section()
+	goto .Lcompile_line_section
 
-.Lcompile_line_program:
-	call _compile_program
-	j .Lcompile_line_section
+	.Lcompile_line_program
+	_compile_program()
+	goto .Lcompile_line_section
 
-.Lcompile_line_comment:
+	.Lcompile_line_comment
 	lw a0, 20(sp)
 	call _skip_comment
-	j .Lcompile_line_section
+	goto .Lcompile_line_section
 
-.Lcompile_line_empty:
+	.Lcompile_line_empty
 	_advance(1)
-	j .Lcompile_line_section
+	goto .Lcompile_line_section
 
-.Lcompile_line_unchanged:
+	.Lcompile_line_unchanged
 	lw a0, 20(sp)
 	call _compile_assembly
-	j .Lcompile_line_section
+	goto .Lcompile_line_section
 
-.Lcompile_line_section:
+	.Lcompile_line_section
 	mv a0, zero
 
-.Lcompile_line_end:
+	.Lcompile_line_end
 end
 
+# Prints ".section .text" and exits.
 proc _compile_text_section()
 begin
 	# .section .text
@@ -1107,31 +1423,40 @@ proc _read_line()
 begin
 	mv t0, s1 # Local position in the source text.
 
-.Lread_line_do:
+	.Lread_line_do
 	lbu t1, (t0) # t1 = Current character.
 	beqz t1, .Lread_line_end # Exit the loop on the NUL character.
 	li t2, '\n'
 	beq t1, t2, .Lread_line_end # Exit the loop on the new line.
 
 	addi t0, t0, 1
-	j .Lread_line_do
+	goto .Lread_line_do
 
-.Lread_line_end:
+	.Lread_line_end
 	sub a0, t0, s1 # Return the line length.
 end
 
 proc _compile()
 begin
-.Lcompile_do:
+	sw zero, 4(sp) # Whether the text section header was already emitted.
+
+	.Lcompile_do
 	lbu t0, (s1) # t0 = Current character.
 	beqz t0, .Lcompile_end # Exit the loop on the NUL character.
 
 	_skip_indentation()
 	call _read_line
+	lw a1, 4(sp)
 	call _compile_line
 
-	j .Lcompile_do
-.Lcompile_end:
+	beqz a0, .Lcompile_do
+	# Update whether the text section header was already emitted.
+	lw t0, 4(sp)
+	or t0, t0, a0
+	sw t0, 4(sp)
+
+	goto .Lcompile_do
+	.Lcompile_end
 end
 
 # Returns the pointer to the current position in the source text in a0.
@@ -1146,6 +1471,12 @@ begin
 	add s1, s1, a0
 end
 
+# Returns the first character in the remaining source text.
+proc _front()
+begin
+	lbu a0, (s1)
+end
+
 # Entry point.
 begin
 	# Read the source from the standard input.
@@ -1155,5 +1486,5 @@ begin
 	call _read_file
 
 	la s1, source_code # s1 = Source code position.
-	call _compile
+	_compile()
 end.
diff --git a/run.rb b/run.rb
deleted file mode 100755
index ac8fc3d..0000000
--- a/run.rb
+++ /dev/null
@@ -1,46 +0,0 @@
-#!/usr/bin/env ruby
-
-require 'open3'
-require 'fileutils'
-require 'pathname'
-
-TMP = Pathname.new 'build'
-CROSS_GCC = '../riscv32-ilp32d--glibc/bin/riscv32-linux-gcc'
-SYSROOT = '../riscv32-ilp32d--glibc/riscv32-buildroot-linux-gnu/sysroot'
-
-COMMON_BOOT_OBJECT = TMP + 'common-boot.o'
-
-FileUtils.rm_rf TMP
-FileUtils.mkdir_p TMP
-
-FileUtils.cp 'boot/asm-boot.s', TMP
-
-def stage(source_elna, stage_name, output)
-  boot_exe = (TMP + stage_name).to_path
-  stage_path = TMP + "#{stage_name}.s"
-  arguments = [CROSS_GCC, '-nostdlib', '-o', boot_exe, stage_path.to_path, COMMON_BOOT_OBJECT.to_path]
-
-  puts(arguments * ' ')
-  system *arguments, exception: true
-
-  arguments = ['qemu-riscv32', '-L', SYSROOT, boot_exe]
-
-  puts(arguments * ' ')
-  puts
-  Open3.popen2(*arguments) do |qemu_in, qemu_out|
-    qemu_in.write source_elna
-    qemu_in.close
-
-    IO.copy_stream qemu_out, output
-    qemu_out.close
-  end
-end
-
-system CROSS_GCC, '-nostdlib', '-c', '-o', COMMON_BOOT_OBJECT.to_path, 'boot/common-boot.s', exception: true
-source_elna = File.read 'boot/goto-boot.elna'
-
-next_stage = TMP + 'goto-boot.s'
-File.open next_stage, 'w' do |output|
-  stage source_elna, 'asm-boot', output
-end
-stage(source_elna, 'goto-boot', $stdout)