8 files changed, 138 insertions, 80 deletions
diff --git a/test/e2e/emulation_speed/bootstrap.atk16 b/test/e2e/bootstrap.atk16
index 9b024e6..9b024e6 100644
--- a/test/e2e/emulation_speed/bootstrap.atk16
+++ b/test/e2e/bootstrap.atk16
diff --git a/test/e2e/call_stack/lib.atk16 b/test/e2e/call_stack/lib.atk16
new file mode 100644
index 0000000..39672e0
--- /dev/null
+++ b/test/e2e/call_stack/lib.atk16
@@ -0,0 +1,42 @@
+@label mul
+  ; multiply a signed/unsigned (a) and an unsigned number (b)
+  ; parameters RA = a
+  ;            RB = b
+  ; return     RG = a * b
+
+  stack_stash RA RB
+  ; initialize return value in RG to 0
+  ldi 0 RG
+@label mul_loop
+  ; if b == 0, we are done
+  subi RB 0 RB
+  bri zero mul_done
+  ; RG += RA
+  add RA RG RG
+  dec RB
+  jpi mul_loop
+@label mul_done
+  stack_restore RA RB
+  return
+
+; Recursive impl of the factorial
+; Calling convention is that arguments are in registers RA..RG (max 7 arguments since RH = SP)
+; and the return value is in RG (note: overwriting arg in RG)
+
+@label fact
+  ; parameters RA = n
+  ; return     RG = factorial(n)
+  subi RA 0 RA
+  bri zero fact_basecase
+@label fact_reccase
+  stack_stash RA RB
+  mov RA RB             ; RB := n
+  subi RA 1 RA          ; RA := n - 1
+  calli fact            ; RG := fact(n - 1)
+  mov RG RA             ; RA := fact(n - 1)
+  calli mul             ; RG := n * fact(n - 1)
+  stack_restore RA RB
+  return
+@label fact_basecase
+  ldi 1 RG
+  return
diff --git a/test/e2e/call_stack/run_fact.atk16 b/test/e2e/call_stack/run_fact.atk16
new file mode 100644
index 0000000..06ad59c
--- /dev/null
+++ b/test/e2e/call_stack/run_fact.atk16
@@ -0,0 +1,11 @@
+; bootstrap code (must be called to setup mandatory data)
+; will jump to label main
+@include ../bootstrap
+@include lib
+
+@let INPUT %INPUT% ; value replaced by test driver code
+
+@label main
+  ldi INPUT RA
+  calli fact
+  hlt
diff --git a/test/e2e/call_stack/run_mul.atk16 b/test/e2e/call_stack/run_mul.atk16
new file mode 100644
index 0000000..feaabe7
--- /dev/null
+++ b/test/e2e/call_stack/run_mul.atk16
@@ -0,0 +1,18 @@
+; bootstrap code (must be called to setup mandatory data)
+; will jump to label main
+@include ../bootstrap
+@include lib
+
+; values replaced by test driver code
+@label INPUT_A
+  %INPUT_A%
+@label INPUT_B
+  %INPUT_B%
+
+@label main
+  ldi INPUT_A RA
+  ldr RA RA
+  ldi INPUT_B RB
+  ldr RB RB
+  calli mul
+  hlt
diff --git a/test/e2e/call_stack/test_call_stack.py b/test/e2e/call_stack/test_call_stack.py
new file mode 100644
index 0000000..3895f5c
--- /dev/null
+++ b/test/e2e/call_stack/test_call_stack.py
@@ -0,0 +1,65 @@
+import time
+from atk16_asm import assemble
+from atk16_emu import Machine
+from test.utils import pad_bytearray
+
+def run_mul(a: int, b: int) -> int:
+  filename = "test/e2e/call_stack/run_mul.atk16"
+  with open(filename, "r") as f:
+    source = f.read()
+
+  source = source.replace("%INPUT_A%", str(a))
+  source = source.replace("%INPUT_B%", str(b))
+
+  obj = assemble(source, filename)
+  rom_image = pad_bytearray(obj.program)
+
+  machine = Machine()
+  machine.load_rom_image(rom_image)
+  machine.reset()
+  machine.run_until_halted()
+
+  return machine.rg.value
+
+def test_mul_1():
+  expected = 30
+  received = run_mul(5, 6)
+
+  assert expected == received
+
+def test_mul_2():
+  a = -100
+  b = 200
+  expected = a * b
+  received = run_mul(a, b)
+
+  assert expected == received
+
+def run_fact(n: int) -> int:
+  filename = "test/e2e/call_stack/run_fact.atk16"
+  with open(filename, "r") as f:
+    source = f.read()
+
+  source = source.replace("%INPUT%", str(n))
+  obj = assemble(source, filename)
+  rom_image = pad_bytearray(obj.program)
+
+  machine = Machine()
+  machine.load_rom_image(rom_image)
+  machine.reset()
+  machine.run_until_halted()
+
+  return machine.rg.value
+
+def test_fact_0():
+  expected = 1
+  received = run_fact(0)
+
+  assert expected == received
+
+def test_fact_6():
+  expected = 720
+  received = run_fact(6)
+
+  assert expected == received
+
diff --git a/test/e2e/emulation_speed/long_loop.atk16 b/test/e2e/emulation_speed/long_loop.atk16
index 2303311..5447256 100644
--- a/test/e2e/emulation_speed/long_loop.atk16
+++ b/test/e2e/emulation_speed/long_loop.atk16
@@ -1,6 +1,6 @@
 ; bootstrap code (must be called to setup mandatory data)
 ; will jump to label main
-@include bootstrap
+@include ../bootstrap
 
 @label iters
   10000
diff --git a/test/e2e/fibo/bootstrap.atk16 b/test/e2e/fibo/bootstrap.atk16
deleted file mode 100644
index 9b024e6..0000000
--- a/test/e2e/fibo/bootstrap.atk16
+++ /dev/null
@@ -1,78 +0,0 @@
-@let SP              RH
-
-; vector table fields
-@let vector_table    0x10
-@let vt_ISR0         0x10 ; ISR0
-@let vt_ISR1         0x11 ; ISR1
-@let vt_ISR2         0x12 ; ISR2
-@let vt_ISR3         0x13 ; ISR3
-@let vt_stack_addr   0x14 ; Stack address
-@let vt_term_pp_addr 0x15 ; Terminal peripheral address
-@let vt_kb_pp_addr   0x16 ; Keyboard peripheral address
-@let vt_gr_mode_addr 0x17 ; Graphics mode setting address
-@let vt_sprite_mem   0x18 ; Sprite memory address
-@let vt_text_mem     0x19 ; Text memory buffer address
-
-; memory segments
-@let stack_segment   0x8000
-@let mmio_segment    0xE000
-@let terminal_addr   0xE000
-@let keyboard_addr   0xE001
-@let gr_mode_addr    0xE002
-@let sprite_mem      0xE800
-@let text_mem        0xF800 ; to 0xFFFF
-; note: sprite memory & text memory can use the same space
-; since they are never used at the same time
-
-; graphics mode settings
-@let gr_disabled_mode 0b00
-@let gr_text_mode     0b01
-@let gr_sprite_mode   0b10
-
-@address vector_table
-  keyboard_isr   ; 0x10
-  hlt_isr        ; 0x11
-  hlt_isr        ; 0x12
-  hlt_isr        ; 0x13
-  stack_segment  ; 0x14
-  terminal_addr  ; 0x15
-  keyboard_addr  ; 0x16
-  gr_mode_addr   ; 0x17
-  sprite_mem     ; 0x18
-  text_mem       ; 0x19
-
-@label hlt_isr
-  ldi 0x55 RE
-  hlt
-
-@label keyboard_isr
-  spu RA
-  spu RB
-  ldi vt_kb_pp_addr RA    ; RA := Keyboard peripheral address pointer
-  ldr RA RA               ; RA := Keyboard peripheral address deref
-  ldr RA RA               ; RA := <16-bit keyboard character code> from MMIO register
-  ldi vt_term_pp_addr RB  ; RB := Terminal peripheral address pointer
-  ldr RB RB               ; RB := Terminal peripheral address deref
-  str RA RB               ; terminal <- character code (ASCII?)
-  mov RA RE               ; RE := character code (for debugging)
-  spo RB
-  spo RA
-  rti
-@label program_segment
-
-; define short prelude that sets up vital instructions
-; NOTE: must be shorter than the vector table offset
-@address 0x0
-; set up stack pointer to point to beginning of stack segment
-  ldi vt_stack_addr RA
-  ldr RA SP
-  jpi program_segment
-
-@address program_segment
-; set graphics mode to disabled
-  ldi vt_gr_mode_addr RA
-  ldr RA RA
-  ldi gr_disabled_mode RB
-  str RB RA
-; jump to main (user defined)
-  jpi main
diff --git a/test/e2e/fibo/fibo.atk16 b/test/e2e/fibo/fibo.atk16
index 2cf3d20..2546f43 100644
--- a/test/e2e/fibo/fibo.atk16
+++ b/test/e2e/fibo/fibo.atk16
@@ -1,6 +1,6 @@
 ; bootstrap code (must be called to setup mandatory data)
 ; will jump to label main
-@include bootstrap
+@include ../bootstrap
 
 @label iters
   51