fix DRW instruction, add arena to iui so I don't need to manage label buffersHEADmaster

6 files changed, 543 insertions, 241 deletions

diff --git a/sources/iui.c b/sources/iui.c
new file mode 100644
index 0000000..6f82ad1
--- /dev/null
+++ b/sources/iui.c
@@ -0,0 +1,300 @@
+/*
+ * Copyright (C) 2025 dwlr <dweller@cabin.digital>
+ *
+ * BSD 3-Clause License (BSD-3-Clause)
+ * See LICENSE for details
+ */
+
+
+#define IUI_TXT_CENTER bit(0)
+#define IUI_CLIP_CLEAR bit(0)
+
+typedef struct
+{
+    enum
+    {
+        IUI_ILL,
+        IUI_BOX,
+        IUI_FILL,
+        IUI_LINE,
+        IUI_TEXT,
+        IUI_CLIP,
+
+    } type;
+
+    u32 color;
+    u16 x, y, w, h;
+    u16 size;
+    u16 flags;
+    char* text;
+
+} iui_cmd;
+
+#define IUI_CMDBUF_LEN 512
+typedef struct
+{
+    arena* ar;
+    void* usr;
+
+    usize hot;
+    usize active;
+    usize kbdfocus;
+
+    /* mouse */
+    u16 x;
+    u16 y;
+
+    u8 pbtns;
+    u8 btns;
+
+    /* TODO: event pump */
+
+    usize ncmds;
+    iui_cmd cmds[IUI_CMDBUF_LEN]; /* TODO: arena? */
+
+} iui;
+
+
+void iui_init(iui* ui, arena* ar, void* usr)
+{
+    if(!ui)
+    {
+        report(WARN, "iui: iui_init() ui == NULL!\n");
+        return;
+    }
+
+    ui->ar  = ar;
+    ui->usr = usr;
+}
+
+void iui_start(iui* ui)
+{
+    assert(ui);
+    ui->hot = 0;
+
+    ar_clear(ui->ar);
+}
+
+void iui_end(iui* ui)
+{
+    assert(ui);
+
+    if(!ui->btns) ui->active = 0;
+    else if(!ui->active) ui->kbdfocus = 0;
+
+    ui->pbtns = ui->btns;
+}
+
+bool iui_mouse_inside(iui* ui, u16 x, u16 y, u16 w, u16 h)
+{
+    return !(ui->x < x || ui->y < y || ui->x >= x + w || ui->y >= y + h);
+}
+
+int iui_button(iui* ui, u16 x, u16 y, int w, int h, char* label)
+{
+    xctx*  x11 = (xctx*)ui->usr;
+    usize   id = (usize)label;
+    bool imhot, imactive;
+
+    if(iui_mouse_inside(ui, x, y, w, h))
+    {
+        bool click = ui->btns & bit(1) && !(ui->pbtns & bit(1));
+        if(!ui->active && click) ui->active = id;
+        ui->hot = id;
+    }
+
+    imhot    = ui->hot    == id;
+    imactive = ui->active == id;
+
+    {
+        iui_cmd cmd = {0};
+        cmd.type = IUI_FILL;
+
+        cmd.x = x;
+        cmd.y = y;
+        cmd.w = w;
+        cmd.h = h;
+
+        if(imhot) cmd.size = 2;
+        else cmd.size = 1;
+
+        if(imactive) cmd.color = x11->cols.as.fg;
+        else cmd.color = x11->cols.as.bg;
+
+        ui->cmds[ui->ncmds++] = cmd;
+
+        cmd.type = IUI_BOX;
+        cmd.color = x11->cols.as.fg;
+        ui->cmds[ui->ncmds++] = cmd;
+
+        cmd.type  = IUI_TEXT;
+        cmd.size  = 14;
+        cmd.text  = label;
+        cmd.flags = IUI_TXT_CENTER;
+
+        if(imactive) cmd.color = x11->cols.as.bg;
+        else cmd.color = x11->cols.as.fg;
+
+        ui->cmds[ui->ncmds++] = cmd;
+    }
+
+    return imhot && imactive && !(ui->btns & bit(1));
+}
+
+void iui_label(iui* ui, u16 x, u16 y, int w, int h, char* fmt, ...)
+{
+    int len = 0;
+    char* buf = NULL;
+    va_list ap = {0};
+    xctx*  x11 = (xctx*)ui->usr;
+
+    buf = ar_push(ui->ar, 512);
+
+    va_start(ap, fmt);
+        len = vsnprintf(buf, 511, fmt, ap);
+    va_end(ap);
+
+    {
+        iui_cmd cmd = {0};
+        cmd.type = IUI_FILL;
+
+        cmd.x = x;
+        cmd.y = y;
+        cmd.w = w;
+        cmd.h = h;
+
+        {
+            iui_cmd clip = cmd;
+            clip.type = IUI_CLIP;
+            clip.flags = 0;
+            clip.x++;
+            clip.y++;
+            clip.w--;
+            clip.h--;
+
+            ui->cmds[ui->ncmds++] = clip;
+        }
+
+        {
+            cmd.type  = IUI_TEXT;
+            cmd.size  = 14;
+            cmd.text  = buf;
+            cmd.flags = 0;
+
+            cmd.x = x + 6;
+            cmd.y = y;
+            cmd.w = w;
+            cmd.h = h;
+
+            cmd.color = x11->cols.as.fg;
+
+            ui->cmds[ui->ncmds++] = cmd;
+        }
+
+        cmd.type  = IUI_CLIP;
+        cmd.flags = IUI_CLIP_CLEAR;
+        ui->cmds[ui->ncmds++] = cmd;
+    }
+}
+
+int iui_editbox(iui* ui, u16 x, u16 y, int w, int h, char* buf, usize buflen)
+{
+    xctx*  x11 = (xctx*)ui->usr;
+    usize   id = (usize)buf;
+    bool imhot, imactive;
+    usize len;
+
+    len = strlen(buf);
+
+    if(iui_mouse_inside(ui, x, y, w, h))
+    {
+        bool click = ui->btns & bit(1) && !(ui->pbtns & bit(1));
+        if(!ui->active && click) ui->active = id;
+        ui->hot = id;
+    }
+
+    imhot    = ui->hot    == id;
+    imactive = ui->active == id;
+
+    {
+        iui_cmd cmd = {0};
+        cmd.type = IUI_FILL;
+
+        cmd.x = x;
+        cmd.y = y;
+        cmd.w = w;
+        cmd.h = h;
+
+        if(imhot) cmd.size = 2;
+        else cmd.size = 1;
+
+        cmd.color = x11->cols.as.bg;
+        ui->cmds[ui->ncmds++] = cmd;
+
+        cmd.type = IUI_BOX;
+        cmd.color = x11->cols.as.fg;
+        ui->cmds[ui->ncmds++] = cmd;
+
+        {
+            iui_cmd clip = cmd;
+            clip.type = IUI_CLIP;
+            clip.flags = 0;
+            clip.x++;
+            clip.y++;
+            clip.w--;
+            clip.h--;
+
+            ui->cmds[ui->ncmds++] = clip;
+        }
+
+        if(imactive) ui->kbdfocus = id;
+        if(ui->kbdfocus == id)
+        {
+            cmd.type = IUI_FILL;
+            cmd.x = x + 6 + 6 * len;
+            cmd.y = y + 6;
+            cmd.w = 10;
+            cmd.h = h - 12;
+            cmd.color = x11->cols.as.fg;
+
+            ui->cmds[ui->ncmds++] = cmd;
+        }
+        else
+        {
+            cmd.type = IUI_BOX;
+            cmd.x = x + 6 + 6 * len;
+            cmd.y = y + 6;
+            cmd.w = 9;
+            cmd.h = h - 13;
+            cmd.color = x11->cols.as.fg;
+            cmd.size = 1;
+
+            ui->cmds[ui->ncmds++] = cmd;
+        }
+
+        {
+            cmd.type  = IUI_TEXT;
+            cmd.size  = 14;
+            cmd.text  = buf;
+            cmd.flags = 0;
+
+            cmd.x = x + 6;
+            cmd.y = y;
+            cmd.w = w;
+            cmd.h = h;
+
+            cmd.color = x11->cols.as.fg;
+
+            ui->cmds[ui->ncmds++] = cmd;
+        }
+
+        cmd.type  = IUI_CLIP;
+        cmd.flags = IUI_CLIP_CLEAR;
+        ui->cmds[ui->ncmds++] = cmd;
+    }
+
+    return imhot && imactive && !(ui->btns & bit(1));
+}
+
+
+void iui_draw(iui* ui);
diff --git a/sources/main.c b/sources/main.c
index 4bc972c..7027451 100644
--- a/sources/main.c
+++ b/sources/main.c
@@ -21,6 +21,8 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include <pthread.h>
+
 #include <X11/Xlib.h>
 #include <X11/Xatom.h>
 #include <X11/Xutil.h>
@@ -28,238 +30,17 @@
 
 #include "bits.c"
 #include "log.c"
+#include "plat.c"
+#include "mem.c"
 #include "tga.c"
 #include "x11.c"
+#include "iui.c"
 
 #include "chip8.c"
 #include "meta/disasm.c"
 #include "meta/exec.c"
 
 
-#define IUI_TXT_CENTER bit(0)
-#define IUI_CLIP_CLEAR bit(0)
-
-typedef struct
-{
-    enum
-    {
-        IUI_ILL,
-        IUI_BOX,
-        IUI_FILL,
-        IUI_LINE,
-        IUI_TEXT,
-        IUI_CLIP,
-
-    } type;
-
-    u32 color;
-    u16 x, y, w, h;
-    u16 size;
-    u16 flags;
-    char* text;
-
-} iui_cmd;
-
-#define IUI_CMDBUF_LEN 512
-typedef struct
-{
-    void* usr;
-
-    usize hot;
-    usize active;
-    usize kbdfocus;
-
-    /* mouse */
-    u16 x;
-    u16 y;
-
-    u8 pbtns;
-    u8 btns;
-
-    /* TODO: event pump */
-
-    usize ncmds;
-    iui_cmd cmds[IUI_CMDBUF_LEN]; /* TODO: arena? */
-
-} iui;
-
-
-void iui_start(iui* ui, void* usr)
-{
-    assert(ui);
-
-    ui->usr = usr;
-    ui->hot = 0;
-}
-
-void iui_end(iui* ui)
-{
-    assert(ui);
-
-    if(!ui->btns) ui->active = 0;
-    else
-    {
-        if(!ui->active) ui->kbdfocus = 0;
-    }
-
-    ui->pbtns = ui->btns;
-}
-
-bool iui_mouse_inside(iui* ui, u16 x, u16 y, u16 w, u16 h)
-{
-    return !(ui->x < x || ui->y < y || ui->x >= x + w || ui->y >= y + h);
-}
-
-int iui_button(iui* ui, u16 x, u16 y, int w, int h, char* label)
-{
-    xctx*  x11 = (xctx*)ui->usr;
-    usize   id = (usize)label;
-    bool imhot, imactive;
-
-    if(iui_mouse_inside(ui, x, y, w, h))
-    {
-        bool click = ui->btns & bit(1) && !(ui->pbtns & bit(1));
-        if(!ui->active && click) ui->active = id;
-        ui->hot = id;
-    }
-
-    imhot    = ui->hot    == id;
-    imactive = ui->active == id;
-
-    {
-        iui_cmd cmd = {0};
-        cmd.type = IUI_FILL;
-
-        cmd.x = x;
-        cmd.y = y;
-        cmd.w = w;
-        cmd.h = h;
-
-        if(imhot) cmd.size = 2;
-        else cmd.size = 1;
-
-        if(imactive) cmd.color = x11->cols.as.fg;
-        else cmd.color = x11->cols.as.bg;
-
-        ui->cmds[ui->ncmds++] = cmd;
-
-        cmd.type = IUI_BOX;
-        cmd.color = x11->cols.as.fg;
-        ui->cmds[ui->ncmds++] = cmd;
-
-        cmd.type  = IUI_TEXT;
-        cmd.size  = 14;
-        cmd.text  = label;
-        cmd.flags = IUI_TXT_CENTER;
-
-        if(imactive) cmd.color = x11->cols.as.bg;
-        else cmd.color = x11->cols.as.fg;
-
-        ui->cmds[ui->ncmds++] = cmd;
-    }
-
-    return imhot && imactive && !(ui->btns & bit(1));
-}
-
-int iui_textbox(iui* ui, u16 x, u16 y, int w, int h, char* buf, usize buflen)
-{
-    xctx*  x11 = (xctx*)ui->usr;
-    usize   id = (usize)buf;
-    bool imhot, imactive;
-    usize len;
-
-    len = strlen(buf);
-
-    if(iui_mouse_inside(ui, x, y, w, h))
-    {
-        bool click = ui->btns & bit(1) && !(ui->pbtns & bit(1));
-        if(!ui->active && click) ui->active = id;
-        ui->hot = id;
-    }
-
-    imhot    = ui->hot    == id;
-    imactive = ui->active == id;
-
-    {
-        iui_cmd cmd = {0};
-        cmd.type = IUI_FILL;
-
-        cmd.x = x;
-        cmd.y = y;
-        cmd.w = w;
-        cmd.h = h;
-
-        if(imhot) cmd.size = 2;
-        else cmd.size = 1;
-
-        cmd.color = x11->cols.as.bg;
-        ui->cmds[ui->ncmds++] = cmd;
-
-        cmd.type = IUI_BOX;
-        cmd.color = x11->cols.as.fg;
-        ui->cmds[ui->ncmds++] = cmd;
-
-        {
-            iui_cmd clip = cmd;
-            clip.type = IUI_CLIP;
-            clip.flags = 0;
-            clip.x++;
-            clip.y++;
-            clip.w--;
-            clip.h--;
-
-            ui->cmds[ui->ncmds++] = clip;
-        }
-
-        if(imactive) ui->kbdfocus = id;
-        if(ui->kbdfocus == id)
-        {
-            cmd.type = IUI_FILL;
-            cmd.x = x + 6 + 6 * len;
-            cmd.y = y + 6;
-            cmd.w = 10;
-            cmd.h = h - 12;
-            cmd.color = x11->cols.as.fg;
-
-            ui->cmds[ui->ncmds++] = cmd;
-        }
-        else
-        {
-            cmd.type = IUI_BOX;
-            cmd.x = x + 6 + 6 * len;
-            cmd.y = y + 6;
-            cmd.w = 9;
-            cmd.h = h - 13;
-            cmd.color = x11->cols.as.fg;
-            cmd.size = 1;
-
-            ui->cmds[ui->ncmds++] = cmd;
-        }
-
-        {
-            cmd.type  = IUI_TEXT;
-            cmd.size  = 14;
-            cmd.text  = buf;
-            cmd.flags = 0;
-
-            cmd.x = x + 6;
-            cmd.y = y;
-            cmd.w = w;
-            cmd.h = h;
-
-            cmd.color = x11->cols.as.fg;
-
-            ui->cmds[ui->ncmds++] = cmd;
-        }
-
-        cmd.type  = IUI_CLIP;
-        cmd.flags = IUI_CLIP_CLEAR;
-        ui->cmds[ui->ncmds++] = cmd;
-    }
-
-    return imhot && imactive && !(ui->btns & bit(1));
-}
-
 void iui_draw(iui* ui)
 {
     usize i;
@@ -348,13 +129,53 @@ void iui_draw(iui* ui)
     ui->ncmds = 0;
 }
 
+void c8_dump_state_iui(chip8* c8, bool stack, iui* ui, u16 x, u16 y)
+{
+    int i = 0;
+
+    u16 dx = x, dy = y;
+    u16 w = 80, h = 10, p = 5;
+
+    for(i = 0; i < (int)sizeof(c8->V); i += 4)
+    {
+        iui_label(ui, dx, dy, w, h, "V%x: %02X (%3d)",  i+0, c8->V[i+0], c8->V[i+0]);
+        dx += w + p;
+
+        iui_label(ui, dx, dy, w, h, "V%x: %02X (%3d)",  i+1, c8->V[i+1], c8->V[i+1]);
+        dx += w + p;
+
+        iui_label(ui, dx, dy, w, h, "V%x: %02X (%3d)",  i+2, c8->V[i+2], c8->V[i+2]);
+        dx += w + p;
+
+        iui_label(ui, dx, dy, w, h, "V%x: %02X (%3d)", i+3, c8->V[i+3], c8->V[i+3]);
+
+        dx = x;
+        dy += h + p;
+    }
+
+    iui_label(ui, dx, dy, 1000, h, "I:%04X SP: %02X DT: %02X ST: %02X CYCLES: %llu KEYS: %X",
+            c8->i, c8->sp, c8->dt, c8->st, c8->cycles, c8->keys);
+#if 0
+    if(stack)
+    {
+        iui_label(ui, "stack:\n");
+        for(i = 0; i < (int)sizeof(c8->STACK); i += 2)
+        {
+            iui_label(ui, "      %-2d: %04X ",  i+0, c8->STACK[i+0]);
+            iui_label(ui, "%-2d: %04X\n", i+1, c8->STACK[i+1]);
+        }
+    }
+#endif
+}
+
 
 int main(int argc, char** argv)
 {
     chip8 c8 = {0};
     xctx x11 = {0};
+    arena ar = {0};
     iui   ui = {0};
-    bool run = true, cycle = false;;
+    bool run = true;
 
     u64   sz = 0;
     FILE*  f = NULL;
@@ -404,7 +225,10 @@ int main(int argc, char** argv)
     }
 
     x11_init(800, 600, "xip-8", argc, argv, &x11);
+    ar_create(4*MB, true, &ar);
+    iui_init(&ui, &ar, &x11);
     c8_reset(&c8);
+    c8.running = false;
 
     while(run)
     {
@@ -520,6 +344,12 @@ int main(int argc, char** argv)
             }
         }
 
+        if(c8.running)
+        {
+            c8_disasm(c8.RAM, c8.pc, buf);
+            c8_exec(c8.RAM, c8.pc, &c8);
+        }
+
         {
             int len = 0;
             char buf[512] = {0};
@@ -539,8 +369,6 @@ int main(int argc, char** argv)
             len = snprintf(buf, lengthof(buf), "cur: %dx%d", ui.x, ui.y);
             XDrawString(x11.disp, x11.wnd, x11.gc, 650, 65, buf, len);
 
-            iui_draw(&ui);
-
             len = snprintf(buf, lengthof(buf), "btn: %d%d%d",
                     ui.btns & bit(1) ? 1 : 0,
                     ui.btns & bit(2) ? 2 : 0,
@@ -555,22 +383,22 @@ int main(int argc, char** argv)
 
             len = snprintf(buf, lengthof(buf), "kbd: %p", (void*)ui.kbdfocus);
             XDrawString(x11.disp, x11.wnd, x11.gc, 650, 125, buf, len);
-        }
-
-        iui_start(&ui, &x11);
-            if(iui_button(&ui, 25, 25, 100, 35, "Cycle")) cycle = !cycle;
-            iui_textbox(&ui, 25, 75, 225, 35, buf, lengthof(buf));
-        iui_end(&ui);
 
+            len = snprintf(buf, lengthof(buf), "ar:  %lu bytes", ar.cursor - ar.base);
+            XDrawString(x11.disp, x11.wnd, x11.gc, 650, 145, buf, len);
 
-        if(cycle)
-        {
-            c8_disasm(c8.RAM, c8.pc, buf);
-            c8_exec(c8.RAM, c8.pc, &c8);
+            iui_draw(&ui);
         }
 
+        iui_start(&ui);
+            c8_dump_state_iui(&c8, false, &ui, 25, 25);
+            iui_editbox(&ui, 25, 600 - 45, 225, 35, buf, lengthof(buf));
+            if(!c8.running && iui_button(&ui, 270, 600 - 45, 100, 35, "Go")) c8.running = true;
+            else if(c8.running && iui_button(&ui, 270, 600 - 45, 100, 35, "Stop")) c8.running = false;
+        iui_end(&ui);
+
         {
-            usize x, y, s = 4;
+            usize x, y, s = 12;
 
             XSetForeground(x11.disp, x11.gc, x11.cols.as.fg);
             XSetBackground(x11.disp, x11.gc, x11.cols.as.bg);
@@ -581,7 +409,7 @@ int main(int argc, char** argv)
                         XFillRectangle(x11.disp, x11.wnd, x11.gc, 25 + x*s, 128 + y*s, s, s);
         }
 
-        usleep(10000);
+        usleep(100);
     }
 
     x11_cleanup(&x11);
diff --git a/sources/mem.c b/sources/mem.c
new file mode 100644
index 0000000..3b111f7
--- /dev/null
+++ b/sources/mem.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2025 dwlr <dweller@cabin.digital>
+ *
+ * BSD 3-Clause License (BSD-3-Clause)
+ * See LICENSE for details
+ */
+
+
+typedef struct
+{
+    u8*   base;
+    u8* cursor;
+    usize size;
+
+} arena;
+
+
+typedef struct
+{
+    u8*   base;
+    ssize pages;
+
+} do_pagefault_args;
+void* do_pagefault(void* arg)
+{
+    ssize i = 0;
+    ssize p = mm_pagesize();
+    do_pagefault_args* args = (do_pagefault_args*)arg;
+    if(!args)
+    {
+        report(ERR, "do_pagefault() with NULL args!\n");
+        return NULL;
+    }
+
+    for(i = 0; i < args->pages; i++) args->base[p * i] = 0;
+
+    return NULL;
+}
+
+bool ar_create(usize size, bool prefault, arena* ar)
+{
+    ssize p = mm_pagesize();
+
+    if(!ar) return false;
+    if(size <= 0) return false;
+
+    size += (size % p) ? (p - (size % p)) : 0;
+
+    ar->base = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
+    if(ar->base == MAP_FAILED) return false;
+    ar->size = size;
+    ar->cursor = ar->base;
+
+    if(prefault)
+    {
+        ssize i = 0;
+        ssize cpus = cpu_count();
+        pthread_t* t = NULL;
+        do_pagefault_args* args = NULL;
+
+        t = calloc(cpus, sizeof(t[0]));
+        if(!t) report(FATAL, "ar_create()/prefault/calloc(t) failed!\n");
+        else
+        {
+            args = calloc(cpus, sizeof(args[0]));
+            if(!args)
+            {
+                free(t);
+                report(FATAL, "ar_create()/prefault/calloc(args) failed!\n");
+            }
+        }
+
+        for(i = 1; i < cpus; i++)
+        {
+            args[i].base  = ar->base + ((size / cpus) * i);
+            args[i].pages = ((size / p) / cpus);
+            pthread_create(&t[i], NULL, do_pagefault, &args[i]);
+        }
+
+        args[0].base  = ar->base;
+        args[0].pages = ((size / p) / cpus);
+        do_pagefault(&args[0]);
+
+        for(i = 1; i < cpus; i++) pthread_join(t[i], NULL);
+
+        free(args);
+        free(t);
+    }
+
+    return true;
+}
+
+#define ar_push(ar, sz) ar_pusha((ar), (sz), sizeof(int), true)
+void* ar_pusha(arena* ar, usize size, usize alignment, bool zero)
+{
+    usize cur, ovfl;
+
+    if(!ar) return NULL;
+    else
+    {
+        cur = align((usize)ar->cursor, alignment);
+        ovfl = (cur + size);
+        if(ovfl < cur) return NULL;
+
+        if(ovfl <= (usize)(ar->base + ar->size))
+        {
+            ar->cursor = (u8*)ovfl;
+
+            if(zero) memset((u8*)cur, 0, size);
+            return (u8*)cur;
+        }
+        else
+        {
+            report(ERR, "arena(%P): overflow @ %P x %llu\n", ar, cur, size);
+            return NULL;
+        }
+    }
+}
+
+void ar_pop(arena* ar, usize size)
+{
+    if(!ar) return;
+    else    ar->cursor = min(ar->base, ar->cursor - size);
+}
+
+void ar_clear(arena* ar)
+{
+    if(ar) ar->cursor = ar->base;
+}
+
+void ar_destroy(arena* ar)
+{
+    if(!ar) return;
+
+    munmap(ar->base, ar->size);
+    ar->base = ar->cursor = NULL;
+    ar->size = 0;
+}
+
diff --git a/sources/meta/exec.c b/sources/meta/exec.c
index 4f34d1b..663a2ae 100644
--- a/sources/meta/exec.c
+++ b/sources/meta/exec.c
@@ -237,7 +237,6 @@ BEGIN \
     if(c8->V[x] != c8->V[y]) c8->pc += 2; \
 END
 
-/* FIXME: correct wrapping, test */
 #define X_C8_DRW \
 BEGIN \
     u8 l; \
@@ -245,7 +244,11 @@ BEGIN \
     u8 cy = c8->V[y]; \
     \
     for(l = 0; l < n; l++) \
-        c8->DISPLAY[(cy + l) % 32] ^= ((u64)c8->RAM[c8->i + l]) << (64 - cx); \
+    { \
+        u64 pix = (u64)c8->RAM[c8->i + l]; \
+        pix = (pix << (64 - cx)) | (pix >> cx); \
+        c8->DISPLAY[(cy + l) % 32] ^= pix; \
+    } \
 END
 
 c8_decode_generate(exec)
diff --git a/sources/plat.c b/sources/plat.c
new file mode 100644
index 0000000..afa0f21
--- /dev/null
+++ b/sources/plat.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2025 dwlr <dweller@cabin.digital>
+ *
+ * BSD 3-Clause License (BSD-3-Clause)
+ * See LICENSE for details
+ */
+
+
+ssize cpu_count(void)
+{
+    static ssize cpus = 0;
+    if(!cpus) cpus = sysconf(_SC_NPROCESSORS_ONLN);
+
+    return cpus;
+}
+
+ssize mm_pagesize(void)
+{
+    static ssize page_size = 0;
+    if(!page_size) page_size = sysconf(_SC_PAGE_SIZE);
+
+    return page_size;
+}
+
diff --git a/sources/x11.c b/sources/x11.c
index b9f27b3..7d353cb 100644
--- a/sources/x11.c
+++ b/sources/x11.c
@@ -1,3 +1,11 @@
+/*
+ * Copyright (C) 2025 dwlr <dweller@cabin.digital>
+ *
+ * BSD 3-Clause License (BSD-3-Clause)
+ * See LICENSE for details
+ */
+
+
 #if true != True
     #error "true != Xlib's True"
 #endif