code.H3RALD.com — xyw: 7481e211d381c9e92082c43239b0007e063d33e5

Added more error codes, fixed minor inconsistencies.

h3rald h3rald@h3rald.com

Tue, 28 Jul 2026 07:14:32 +0200

commit

7481e211d381c9e92082c43239b0007e063d33e5

parent

eb2365b3bdfc2a620e2da1a4975eab4b60910efe

10 files changed, 49 insertions(+), 27 deletions(-)

jump to

devices/clock.c

devices/clock.h

devices/file.c

devices/file.h

devices/system.c

devices/system.h

devices/terminal.c

devices/terminal.h

xyw.h

xywrun.c

M devices/clock.c → devices/clock.c

@@ -114,9 +114,10 @@ #endif
     return -1; // active handler, no event yet
 }
 
-void clock_setup(xyw_byte *data)
+void clock_setup(xyw_byte *data, xyw_byte *error)
 {
     (void)data;
+    (void)error;
     clock_timer_active = 0;
     clock_timer_elapsed_pending = 0;
 #ifdef _WIN32

M devices/clock.h → devices/clock.h

@@ -1,6 +1,6 @@ 
 #include "../xyw.h"
 
-void clock_setup(xyw_byte *data);
+void clock_setup(xyw_byte *data, xyw_byte *error);
 xyw_byte clock_input(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 void clock_output(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 int clock_poll(xyw_byte *data);

M devices/file.c → devices/file.c

@@ -578,8 +578,9 @@ 
     XYW_POKEW(&data[FILE_SUCCESS], 1);
 }
 
-void file_setup(xyw_byte *data)
+void file_setup(xyw_byte *data, xyw_byte *error)
 {
+    (void)error;
     // Close any open file 
     file_close();

M devices/file.h → devices/file.h

@@ -1,5 +1,5 @@ 
 #include "../xyw.h"
 
-void file_setup(xyw_byte *data);
+void file_setup(xyw_byte *data, xyw_byte *error);
 xyw_byte file_input(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 void file_output(xyw_byte *data, xyw_byte addr, xyw_byte *error);

M devices/system.c → devices/system.c

@@ -24,9 +24,10 @@ static int exec_stack_depth = 0;
 static int exec_pending = 0;
 static char exec_path_buf[MAX_IMAGE_EXEC_PATH_LENGTH];
 
-void system_setup(xyw_byte *data)
+void system_setup(xyw_byte *data, xyw_byte *error)
 {
     (void)data;
+    (void)error;
     srand(time(NULL));
     error_handler_entry_s = 0;
     error_handler_armed = 0;

M devices/system.h → devices/system.h

@@ -1,6 +1,6 @@ 
 #include "../xyw.h"
 
-void system_setup(xyw_byte *data);
+void system_setup(xyw_byte *data, xyw_byte *error);
 xyw_byte system_input(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 void system_output(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 void system_tick(xyw_byte *data);

M devices/terminal.c → devices/terminal.c

@@ -16,7 +16,8 @@ #define TERMINAL_OUTPUT 0x1
 #define TERMINAL_ON_KEYPRESS 0x2
 #define TERMINAL_ON_ARGUMENT 0x4
 
-#define POLL_INTERVAL_MS 100
+#define TERMINAL_POLL_INTERVAL_MS 100
+#define TERMINAL_ERROR_NOT_A_TTY 0x11
 
 //// Platform-specific non-blocking key input
 
@@ -33,7 +34,7 @@ }
 #else
 static int getch_timeout(int timeout_ms)
 {
-    (void)timeout_ms; // bounded by VMIN=0/VTIME in terminal_init()
+    (void)timeout_ms; // bounded by VMIN=0/VTIME in terminal_setup()
     int c = getchar();
     return (c == EOF) ? 0 : c;
 }
@@ -126,7 +127,7 @@ // Keypress handling
     xyw_word on_keypress_handler = XYW_PEEKW(&data[TERMINAL_ON_KEYPRESS]);
     if (on_keypress_handler)
     {
-        int c = getch_timeout(POLL_INTERVAL_MS);
+        int c = getch_timeout(TERMINAL_POLL_INTERVAL_MS);
         if (c > 0)
         {
             if (c == 3 || c == 4)
@@ -148,9 +149,10 @@ }
 
 //// Device init/teardown/IO
 
-void terminal_init(xyw_byte *data)
+void terminal_setup(xyw_byte *data, xyw_byte *error)
 {
     (void)data;
+    (void)error;
     // Reset arg feeding state for fresh image
     arg_index = 1;
     arg_char_pos = 0;
@@ -160,12 +162,14 @@ struct termios raw;
 
     if (!isatty(STDIN_FILENO))
     {
+        *error = TERMINAL_ERROR_NOT_A_TTY;
         return;
     }
 
     if (tcgetattr(STDIN_FILENO, &terminal_orig_termios) != 0)
     {
         XYW_DBG("terminal: tcgetattr failed, raw mode not enabled\n");
+        *error = TERMINAL_ERROR_NOT_A_TTY;
         return;
     }
 
@@ -177,6 +181,7 @@ 
     if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) != 0)
     {
         XYW_DBG("terminal: tcsetattr failed, raw mode not enabled\n");
+        *error = TERMINAL_ERROR_NOT_A_TTY;
         return;
     }

M devices/terminal.h → devices/terminal.h

@@ -1,6 +1,6 @@ 
 #include "../xyw.h"
 
-void terminal_init(xyw_byte *data);
+void terminal_setup(xyw_byte *data, xyw_byte *error);
 void terminal_output(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 xyw_byte terminal_input(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 void terminal_teardown(xyw_byte *data);

M xyw.h → xyw.h

@@ -22,11 +22,14 @@ 
 // System Errors
 #define XYW_SYSTEM_ERROR_NONE 0x00
 #define XYW_SYSTEM_ERROR_DIVISION_BY_ZERO 0x01
-#define XYW_SYSTEM_ERROR_STACK_UNDERFLOW 0x02
-#define XYW_SYSTEM_ERROR_STACK_OVERFLOW 0x03
-#define XYW_SYSTEM_ERROR_EXEC_DEPTH_EXCEEDED 0x04
-#define XYW_SYSTEM_ERROR_IMAGE_NOT_FOUND 0x05
-#define XYW_SYSTEM_ERROR_IMAGE_READ_ERROR 0x06
+#define XYW_SYSTEM_ERROR_USER_STACK_UNDERFLOW 0x02
+#define XYW_SYSTEM_ERROR_USER_STACK_OVERFLOW 0x03
+#define XYW_SYSTEM_ERROR_SYSTEM_STACK_UNDERFLOW 0x04
+#define XYW_SYSTEM_ERROR_SYSTEM_STACK_OVERFLOW 0x05
+#define XYW_SYSTEM_ERROR_EXEC_DEPTH_EXCEEDED 0x06
+#define XYW_SYSTEM_ERROR_IMAGE_NOT_FOUND 0x07
+#define XYW_SYSTEM_ERROR_IMAGE_READ_ERROR 0x08
+#define XYW_SYSTEM_ERROR_INVALID_OPCODE 0x09
 
 typedef unsigned char xyw_byte;
 typedef unsigned short xyw_word;
@@ -40,7 +43,7 @@ 
 // Devices API
 typedef xyw_byte (*xyw_input)(xyw_byte *data, xyw_byte addr, xyw_byte *error);
 typedef void (*xyw_output)(xyw_byte *data, xyw_byte addr, xyw_byte *error);
-typedef void (*xyw_setup)(xyw_byte *data);
+typedef void (*xyw_setup)(xyw_byte *data, xyw_byte *error);
 typedef void (*xyw_teardown)(xyw_byte *data);
 typedef int (*xyw_poll)(xyw_byte *data); // returns: 1=dispatched, 0=inactive, -1=active but no event
 typedef void (*xyw_save)(xyw_byte *data, xyw_byte *state);

M xywrun.c → xywrun.c

@@ -119,7 +119,7 @@ static void ss_push_frame(xyw_word return_addr)
 {
     if (s >= SYSTEM_MAX_FRAMES)
     {
-        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_STACK_OVERFLOW;
+        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_SYSTEM_STACK_OVERFLOW;
         return;
     }
     xyw_byte *base = &system_stack[s * SYSTEM_FRAME_SIZE];
@@ -138,7 +138,7 @@ static xyw_word ss_pop_frame()
 {
     if (s < 1)
     {
-        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_STACK_UNDERFLOW;
+        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_SYSTEM_STACK_UNDERFLOW;
         return -1;
     }
     s--;
@@ -218,7 +218,7 @@ static void us_push(xyw_byte val)
 {
     if (u > XYW_USER_STACK_SIZE - 1)
     {
-        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_STACK_OVERFLOW;
+        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_USER_STACK_OVERFLOW;
         return;
     }
     XYW_DBG(" => %02X\n", val);
@@ -229,7 +229,7 @@ static void us_pushw(xyw_word val)
 {
     if (u > XYW_USER_STACK_SIZE - 2)
     {
-        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_STACK_OVERFLOW;
+        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_USER_STACK_OVERFLOW;
         return;
     }
     user_stack[u]     = (xyw_byte)(val >> 8);
@@ -242,7 +242,7 @@ static xyw_byte us_pop()
 {
     if (u < 1)
     {
-        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_STACK_UNDERFLOW;
+        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_USER_STACK_UNDERFLOW;
         return -1;
     }
     u -= 1;
@@ -255,7 +255,7 @@ static xyw_word us_popw()
 {
     if (u < 2)
     {
-        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_STACK_UNDERFLOW;
+        xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_USER_STACK_UNDERFLOW;
         return -1;
     }
     xyw_word val = (xyw_word)((user_stack[u - 2] << 8) | user_stack[u - 1]);
@@ -351,7 +351,7 @@ xyw_device xyw_devices[XYW_TOTAL_DEVICES] = {
     // System device
     {DEV_DATA(0), system_setup, system_input, system_output, 0, 0, system_save, system_restore, system_tick},
     // Terminal device
-    {DEV_DATA(1), terminal_init, terminal_input, terminal_output, terminal_teardown, terminal_poll, terminal_save, terminal_restore, 0},
+    {DEV_DATA(1), terminal_setup, terminal_input, terminal_output, terminal_teardown, terminal_poll, terminal_save, terminal_restore, 0},
     // Clock device
     {DEV_DATA(2), clock_setup, clock_input, clock_output, 0, clock_poll, 0, 0, 0},
     // File device
@@ -412,9 +412,13 @@ xyw_exec_args_active = snap->exec_args_active;
     for (int i = 0; i < XYW_TOTAL_DEVICES; i++)
     {
         if (xyw_devices[i].restore)
+        {
             xyw_devices[i].restore(xyw_devices[i].data, snap->device_state[i]);
+        }
         else if (xyw_devices[i].setup)
-            xyw_devices[i].setup(xyw_devices[i].data);
+        {
+            xyw_devices[i].setup(xyw_devices[i].data, dev_error);
+        }
     }
 }
 
@@ -440,9 +444,13 @@ }
     xyw_memory[SYSTEM_STATE] |= XYW_STATE_RUNNING;
 
     for (int i = 0; i < XYW_TOTAL_DEVICES; i++)
+    {
         if (xyw_devices[i].setup)
-            xyw_devices[i].setup(xyw_devices[i].data);
-
+        {
+            xyw_devices[i].setup(xyw_devices[i].data, dev_error);
+        }
+    }
+        
     xyw_memory[SYSTEM_PAGE] = 0xff;
     *pc = 0x0000;
 
@@ -580,6 +588,9 @@ /* JCN */ OPC_SR1(0x1D, , xyw_word addr = ADDR(ARG); xyw_byte cond = us_pop(); if (cond) { *pc = addr-1; });
             /* JSR */ OPC_SR1(0x1E, xyw_word addr = ADDR(ARG),  ss_push_frame(*pc+1); *pc = addr-1;);
             /* RTS */ case 0x1F: 
                 *pc = ss_pop_frame()-1; 
+                break;
+            default:
+                xyw_memory[SYSTEM_ERROR] = XYW_SYSTEM_ERROR_INVALID_OPCODE;
                 break;
             // clang-format on
         }

all repos — xyw @ 7481e211d381c9e92082c43239b0007e063d33e5

A minimal virtual machine and assembler for terminals.