Add initial implementation of DEO/DEO2

2 files changed, 113 insertions, 7 deletions

diff --git a/src/main.c b/src/main.c
index 41f3f21..5696b21 100644
--- a/src/main.c
+++ b/src/main.c
@@ -32,7 +32,8 @@ extern void uxn_eval_asm(u16 pc);
 // we will use very often.
 extern u8 wst[256];
 extern u8 rst[256];
-extern u8 io_ports[256];
+extern uintptr_t deo_map[16];
+extern uintptr_t dei_map[16];
 extern uintptr_t wst_ptr;
 extern uintptr_t rst_ptr;
 
@@ -40,6 +41,33 @@ EWRAM_BSS
 u8 uxn_ram[KB(64)];
 
 void
+stub_a(u8 port, u16 val) {
+    (void)port;
+    (void)val;
+    txt_printf("a");
+}
+
+void
+deo_console(u8 port, u16 val) {
+    switch(port) {
+    case 0x8:
+        txt_putc(val);
+        return;
+    case 0x9:
+        txt_printf("ERROR: %c");
+        txt_putc(val);
+        return;
+    }
+}
+
+void
+stub_c(u8 port, u16 val) {
+    (void)port;
+    (void)val;
+    txt_printf("c");
+}
+
+void
 init_uxn() {
     // Initialize uxn.
     u32 fill = 0;
@@ -160,7 +188,12 @@ init_uxn() {
         // 0x40, 0x00, 0x03, 0x80, 0xff, 0x00, 0xa0, 0xaa, 0xbb, 0xa0, 0xcc, 0xdd,
         // 0x60, 0x00, 0x03, 0x80, 0xff, 0x00, 0xa0, 0xaa, 0xbb, 0xa0, 0xcc, 0xdd,
         // 0x60, 0x00, 0x03, 0x80, 0xff, 0x00, 0xa0, 0xaa, 0xbb, 0xa0, 0xcc, 0xdd, 0x6c
-        0x80, 0x01, 0x20, 0x00, 0x03, 0x80, 0xff, 0x00, 0xa0, 0xaa, 0xbb, 0xa0, 0xcc, 0xdd,
+        // 0x80, 0x01, 0x20, 0x00, 0x03, 0x80, 0xff, 0x00, 0xa0, 0xaa, 0xbb, 0xa0, 0xcc, 0xdd,
+        // DEO/DEO2
+        // 0x80, 0x68, 0x80, 0x18, 0x17, 0x80, 0x65, 0x80,  0x18, 0x17, 0x80, 0x6c, 0x80, 0x18, 0x17, 0x80,
+        // 0x6c, 0x80, 0x18, 0x17, 0x80, 0x6f, 0x80, 0x18,  0x17, 0x80, 0x0a, 0x80, 0x18, 0x17,
+        0xa0, 0x00, 0x68, 0x80, 0x18, 0x37, 0x80, 0x65, 0x80,  0x18, 0x17, 0x80, 0x6c, 0x80, 0x18, 0x17, 0x80,
+        0x6c, 0x80, 0x18, 0x17, 0x80, 0x6f, 0x80, 0x18,  0x17, 0x80, 0x0a, 0x80, 0x18, 0x17,
     };
     memcpy(uxn_ram + PAGE_PROGRAM, uxn_rom, sizeof(uxn_rom));
 }
@@ -209,8 +242,12 @@ main(void) {
     for (size_t i = 0; i < 256; i++) {
         wst[i] = 0;
         rst[i] = 0;
-        io_ports[i] = 0;
+        // TODO: Init device memory.
     }
+    deo_map[0] = stub_a;
+    deo_map[1] = deo_console;
+    deo_map[2] = stub_c;
+    // ...
 
     uxn_eval_asm(PAGE_PROGRAM);
 
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: