Add initial implementation of DEO/DEO2

1 files changed, 73 insertions, 4 deletions

diff --git a/src/uxn-core.s b/src/uxn-core.s
index d32f303..c73d44c 100644
--- a/src/uxn-core.s
+++ b/src/uxn-core.s
@@ -17,16 +17,16 @@ rst: .space 256
 .global rst_ptr
 rst_ptr: .word rst
 
-.global io_ports
-io_ports: .space 256
+.global device_data
+device_data: .space 256
 
 @ UXN evaluation function.
 @
-@   r0: PC pointer (argument is offset from RAM).
+@   r0: PC pointer (argument for this function is the offset from UXN RAM).
 @   r1: Stack pointer (wst).
 @   r2: Stack pointer (rst).
-@   r7: Ram ptr.
 @   r3-r6: Scratch registers.
+@   r7: Ram ptr.
 @
 .global uxn_eval_asm
 uxn_eval_asm:
@@ -155,7 +155,10 @@ uxn_ret:
     strb    \a, [\off]
 .endm
 
+@
 @ OP table
+@
+
 op_table:
     .word brk   @ 0x00
     .word inc   @ 0x01
@@ -769,16 +772,82 @@ sta2:
     asave16 r3, r4
     b       uxn_decode
 
+.global dei_map
+dei_map:
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+
 dei:
     b       uxn_decode
 
 dei2:
     b       uxn_decode
 
+.global deo_map
+deo_map:
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+    .word uxn_ret
+
 deo:
+    wpop8   r3
+    mov     r4, r3, lsr #4 @ idx
+    and     r3, #0x0f      @ port
+    wpop8   r5             @ value
+    adr     r6, deo_map
+    ldr     r6, [r6, r4, lsl #2]
+    stmfd   sp!, {r0, r7, lr}
+    mov     r0, r3
+    mov     r1, r5
+    mov     lr, pc
+    bx      r6
+    ldmfd   sp!, {r0, r7, lr}
+    ldr     r1, wst_ptr
+    ldr     r2, rst_ptr
     b       uxn_decode
 
 deo2:
+    wpop8   r3
+    mov     r4, r3, lsr #4 @ idx
+    and     r3, #0x0f      @ port
+    wpop16  r5, r6         @ value
+    adr     r6, deo_map
+    ldr     r6, [r6, r4, lsl #2]
+    stmfd   sp!, {r0, r7, lr}
+    mov     r0, r3
+    mov     r1, r5
+    mov     lr, pc
+    bx      r6
+    ldmfd   sp!, {r0, r7, lr}
+    ldr     r1, wst_ptr
+    ldr     r2, rst_ptr
     b       uxn_decode
 
 add: