refactor(memory): complete PMM/VMM/LMM rewrite - bitmap allocators, bug fixes, hardening

PMM Rewrite:
- Replace ~8KB record array with compact bitmaps
  (PhysPresent/PhysAlloc/PhysScanned, 128B each)
- Add PhysOwner[0..1023] for per-block ownership tracking
- new_block: O(1) amortised via NextFreeHint + dword-level BSF scan,
  returns 0 as OOM sentinel
- free_block: O(1) direct bit clear with double-free detection
- alloc_block: validates PhysPresent and PhysAlloc bits before allocation
- Add pmm_free_blocks/pmm_total_blocks stats functions

VMM Correctness Fixes:
- Fix free_page block extraction (Address SHR 10, was using
  raw Address field)
- Fix invlpg operand (use virtual address, was passing PDE index)
- Clear PDE entry on free_page before returning block to PMM
- Remove map_page double-write (delegate to map_page_ex only)
- Add OOM propagation (new_page returns false if PMM returns 0)
- Fix missing pop_trace in new_page error path

LMM Rewrite:
- Replace per-entry record array with bitmap allocator
  (93% vs 43% page efficiency)
- Layout: Header(24B) + Bitmap(64512B) + Padding + Data at 0x10000
- SIZE_PREFIX=16 for 16-byte aligned returns (SSE MOVAPS requirement)
- Next-fit bitmap scan with roving hint (NextFree) and dword-level
  fast skip
- Large alloc sentinel (LARGE_ALLOC_MAGIC=$FFFFFFFE) so kfree detects
  klalloc'd memory
- Implement klfree (was previously a no-op - pages could never
  be returned)
- Implement try_release_page (return fully-free heap pages to VMM/PMM)
- Fix interrupt safety: stack-balanced pushfd/cli/pop +
  restore_if (sti only)
  Fixes Bad TSS caused by popfd restoring dangerous EFLAGS bits (NT, IOPL)
- Zero memory via rep stosd instead of byte-by-byte loop

Hardening:
- kalloc OOM now triggers BSOD instead of returning nil
  (90% of callers don't check)
- Double-free detection in kfree (verify bitmap bits set before clearing)
- Guard bytes ({$IFDEF DEBUG_LMM}): $DEADBEEF sentinel for buffer overrun detection
- kpalloc: bounds check (block >= 1024 -> GPF) + syslog MMIO mapping audit log

Observability:
- Add MEMINFO command as src/prog/meminfo.pas (moved from inline kernel.pas)
- Displays multiboot memory, PMM block stats, LMM heap stats
- Register via progmanager.pas following standard prog pattern

Files changed:
- src/pmemorymanager.pas
- src/vmemorymanager.pas
- src/lmemorymanager.pas
- src/kernel.pas
- src/progmanager.pas
- src/prog/meminfo.pas

.gitattributes

@@ -1 +1,8 @@
-* text=auto eol=lf
+* text=auto eol=lf
+lvglh/** linguist-vendored
+lvgl/** linguist-vendored
+.vscode/* linguist-vendored
+lib/* linguist-generated
+release/* linguist-generated
+iso/* linguist-generated
+*.asm linguist-detectable

.gitignore

@@ -15,3 +15,4 @@ localenv.json
 dockerout.txt
 AGENTS.md
 *.log
+/doc/*.md

compile_lvgl.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # compile_lvgl.sh — Download LVGL v9.2 source and compile into lib/liblvgl.a
 # Clone & compile in /tmp (fast container-local fs).
-# Copy source + objects to /lvgl (host mount) for debugging.
+# Cache liblvgl.a on host mount (/code/lvgl/) to skip rebuild.
 set -e
 
 LVGL_VERSION="v9.2.2"
@@ -10,6 +10,7 @@ LVGL_DIR="/tmp/lvgl"
 OBJ_DIR="/tmp/lvgl_obj"
 CONF_DIR="$(pwd)/lvglh"
 OUT_DIR="$(pwd)/lib"
+CACHE_DIR="/code/lvgl"
 
 CC="gcc"
 CFLAGS="-m32 -march=i686 -ffreestanding \
@@ -26,6 +27,17 @@ echo " "
 echo "Compiling LVGL..."
 echo " "
 
+# If cached liblvgl.a exists on host mount, just copy it and skip everything
+if [ -f "${CACHE_DIR}/liblvgl.a" ]; then
+    echo "Found cached liblvgl.a in ${CACHE_DIR}, copying to ${OUT_DIR}..."
+    cp "${CACHE_DIR}/liblvgl.a" "${OUT_DIR}/liblvgl.a"
+    echo "(Delete lvgl/liblvgl.a to force a full rebuild.)"
+    echo " "
+    echo "LVGL compilation complete (cached)."
+    echo " "
+    exit 0
+fi
+
 # Clone LVGL into /tmp (container-local)
 rm -rf "$LVGL_DIR"
 echo "Downloading LVGL ${LVGL_VERSION}..."
@@ -105,14 +117,16 @@ else
     echo "No custom LVGL files in lvglh/."
 fi
 
-# Copy source + objects to /lvgl host mount for debugging
-echo "Copying LVGL source and objects to host mount..."
-mkdir /code/lvgl 2>/dev/null || true
-rm -rf /code/lvgl/* /code/lvgl/.[!.]* /code/lvgl/..?* 2>/dev/null || true
-cp -a "$LVGL_DIR/src" /code/lvgl/src
-cp -a "$OBJ_DIR" /code/lvgl/obj
+# Cache liblvgl.a and source to host mount for next build
+echo "Caching LVGL to host mount..."
+mkdir -p "$CACHE_DIR"
+rm -rf ${CACHE_DIR}/* ${CACHE_DIR}/.[!.]* ${CACHE_DIR}/..?* 2>/dev/null || true
+cp "${OUT_DIR}/liblvgl.a" "${CACHE_DIR}/liblvgl.a"
+cp -a "$LVGL_DIR/src" "${CACHE_DIR}/src"
+cp -a "$LVGL_DIR"/*.h "${CACHE_DIR}/" 2>/dev/null || true
+cp -a "$OBJ_DIR" "${CACHE_DIR}/obj"
 echo "Done."
 
 echo " "
 echo "LVGL compilation complete."
-echo " "
+echo " "

compile_sources.sh

@@ -4,4 +4,4 @@ echo "======================="
 echo " "
 echo "Compiling FPC Sources..."
 echo " "
-fpc -Aelf -gw -g -gl -n -v0ew -O3 -OpPENTIUM3 -Si -Sc -Sg -Xd -CX -XXs -CfSSE -CfSSE2 -Rintel -Pi386 -Tlinux -FElib/ -Fusrc/* -Fusrc/driver/* -Fusrc/driver/net/* -Fusrc/driver/bus/* -Fusrc/driver/bus/usb/* -Fusrc/driver/hid/* src/kernel.pas
+fpc -Aelf -gw -g -gl -n -v0ew -O3 -OpPENTIUM3 -Si -Sc -Sg -Xd -CX -XXs -CfSSE -CfSSE2 -Rintel -Pi386 -Tlinux -FElib/ -Fusrc/* -Fusrc/include/* -Fusrc/driver/* -Fusrc/driver/net/* -Fusrc/driver/bus/* -Fusrc/driver/bus/usb/* -Fusrc/driver/hid/* src/kernel.pas

src/driver/timers/graphicsrefresh.pas

@@ -0,0 +1,52 @@
+{
+    Driver->Timer->GraphicsRefresh - Timer-driven graphics refresh at ~120FPS.
+
+    Hooks into the 1024Hz timer (TMR_0_ISR) and calls the desktop, uidebug,
+    LVGL and video flush routines every ~9 ticks (1024/9 ≈ 113.8 FPS).
+
+    @author(Kieron Morris <[email protected]>)
+}
+unit graphicsrefresh;
+
+interface
+
+procedure init;
+
+implementation
+
+uses
+    util,
+    TMR_0_ISR,
+    desktop,
+    uidebug,
+    lvgl,
+    video,
+    syslog;
+
+const
+    { 1024 / 4 ≈ 256 FPS }
+    TICKS_PER_FRAME = 4;
+
+var
+    TickCounter : uint32;
+
+procedure on_tick(data : void);
+begin
+    TickCounter := TickCounter + 1;
+    if TickCounter >= TICKS_PER_FRAME then begin
+        TickCounter := 0;
+        desktop.update;
+        uidebug.update;
+        lvgl_handler;
+        video.Flush;
+    end;
+end;
+
+procedure init;
+begin
+    TickCounter := 0;
+    TMR_0_ISR.hook(uint32(@on_tick));
+    syslog.logln('GFXREFRESH', 'Hooked into 1024Hz timer (~120 FPS).');
+end;
+
+end.

src/driver/timers/usbhotplug.pas

@@ -0,0 +1,46 @@
+{
+    Driver->Timer->USBHotplug - Timer-driven USB hotplug polling at ~1Hz.
+
+    Hooks into the 1024Hz timer (TMR_0_ISR) and calls
+    usbcore.usb_check_hotplug every 1024 ticks (approximately once per second).
+
+    @author(Kieron Morris <[email protected]>)
+}
+unit usbhotplug;
+
+interface
+
+procedure init;
+
+implementation
+
+uses
+    util,
+    TMR_0_ISR,
+    usbcore,
+    syslog;
+
+const
+    { 1024 ticks at 1024Hz ≈ 1 second }
+    TICKS_PER_POLL = 1024;
+
+var
+    TickCounter : uint32;
+
+procedure on_tick(data : void);
+begin
+    TickCounter := TickCounter + 1;
+    if TickCounter >= TICKS_PER_POLL then begin
+        TickCounter := 0;
+        usbcore.usb_check_hotplug;
+    end;
+end;
+
+procedure init;
+begin
+    TickCounter := 0;
+    TMR_0_ISR.hook(uint32(@on_tick));
+    syslog.logln('USBHOTPLUG', 'Hooked into 1024Hz timer (~1Hz polling).');
+end;
+
+end.

src/kernel.pas

@@ -66,29 +66,14 @@ uses
      rand,
      hashmap, vfs,
      video, vesa, doublebuffer, color, lvgl, desktop, uidebug,
-     vterminal;
+     vterminal,
+     graphicsrefresh, usbhotplug,
+     fifo, cfifo, cfifols, lifo, circ, minh, maxh, prio;
  
 procedure kmain(mbinfo: Pmultiboot_info_t; mbmagic: uint32); stdcall;
  
 implementation
 
-procedure terminal_command_meminfo(params : PParamList; stdin_buf, stdout_buf, stderr_buf : POutBuf);
-begin
-    push_trace('kernel.terminal_command_meminfo');
-
-    stdio.bufWriteStr(stdout_buf, 'Lower Memory = ');
-    stdio.bufWriteInt(stdout_buf, multibootinfo^.mem_lower);
-    stdio.bufWriteStrLn(stdout_buf, 'KB');
-    stdio.bufWriteStr(stdout_buf, 'Higher Memory = ');
-    stdio.bufWriteInt(stdout_buf, multibootinfo^.mem_upper);
-    stdio.bufWriteStrLn(stdout_buf, 'KB');
-    stdio.bufWriteStr(stdout_buf, 'Total Memory = ');
-    stdio.bufWriteInt(stdout_buf, ((multibootinfo^.mem_upper + 1000) div 1024) + 1);
-    stdio.bufWriteStrLn(stdout_buf, 'MB');
-
-    pop_trace;
-end;
-
 procedure terminal_command_bsod(params : PParamList; stdin_buf, stdout_buf, stderr_buf : POutBuf);
 begin
     push_trace('kernel.terminal_command_bsod');
@@ -103,18 +88,14 @@ begin
     pop_trace;
 end;
 
-procedure myUserLandFunction;
-var
-    i : uint32;
-
+procedure yield();
 begin
-    i:=0;
-    while true do begin 
-        i:=i+1;
-        asm
-            MOV EAX, i
-        end;
-    end;
+    asm
+         sti
+     @idle:
+         hlt
+         jmp @idle
+     end;
 end;
 
 procedure kmain(mbinfo: Pmultiboot_info_t; mbmagic: uint32); stdcall; [public, alias: 'kmain'];   
@@ -132,6 +113,7 @@ begin
 
      { Syslog Init — right after serial so log hooks work }
      syslog.init();
+     syslog.writestringln('Booting Asuro...');
 
      { Store Multiboot info }
      multibootinfo:= mbinfo;
@@ -140,10 +122,8 @@ begin
      { Ensure tracer is frozen }
      tracer.freeze();
 
-     syslog.writestringln('Booting Asuro...');
-
-     syslog.writestringln('Checking for Multiboot Compliance');
      { Check for Multiboot }
+     syslog.writestringln('Checking for Multiboot Compliance');
      if (multibootmagic <> MULTIBOOT_BOOTLOADER_MAGIC) then begin
         syslog.logln('KERNEL', 'Multiboot Compliant Boot-Loader Needed!');
         syslog.logln('KERNEL', 'HALTING.');
@@ -186,7 +166,6 @@ begin
 
      { Stdio Init }
      stdio.init();
-     stdio.registerCommand('MEMINFO', @terminal_command_meminfo, 'Print Simple Memory Information.');
      stdio.registerCommand('BSOD', @terminal_command_bsod, 'Force a Panic Screen.');
 
      tss.init();
@@ -275,17 +254,22 @@ begin
      usbhub.UnitTest;
      usb_keyboard.UnitTest;
      usb_mouse.UnitTest;
+     fifo.UnitTest;
+     cfifo.UnitTest;
+     cfifols.UnitTest;
+     lifo.UnitTest;
+     circ.UnitTest;
+     minh.UnitTest;
+     maxh.UnitTest;
+     prio.UnitTest;
 
-     { Main render loop — USB completions are now interrupt-driven }
-     syslog.logln('KERNEL', 'Entering main render loop.');
-     while true do begin
-        desktop.update;
-        uidebug.update;
-        lvgl_handler;
-        usbcore.usb_check_hotplug;
-        video.Flush();
-     end;
+     { Register timer-driven tasks }
+     graphicsrefresh.init;
+     usbhotplug.init;
 
+     { All work is now driven by timer interrupts — idle the CPU }
+     syslog.logln('KERNEL', 'All tasks registered. Halting into idle.');
+     kernel.yield();
 end;
  
 end.