Fix PS/2 mouse ISR blocking; convert USB polling & GFX refresh to processes; remove dead scheduler

PS/2 Mouse:
- Fix ISR spin-blocking by reading port $60 directly with inb() instead
  of calling mouse_read(), which uses mouse_wait_long (100k iterations)
  and would stall the interrupt handler waiting for the next packet byte.

Timer (PIT):
- Increase PIT frequency from ~1024 Hz to ~8 kHz (divisor 1193 -> 149)
  for more granular timer ticks.

Graphics Refresh:
- Replace timer-hook-driven rendering (driver/timers/graphicsrefresh)
  with a dedicated 'gfxd' process that runs a continuous render loop,
  keeping the vCPU active to avoid NEM/Hyper-V pause-loop descheduling.
- Move uidebug from driver/video/ to prog/.
- Update FPS calculation to account for 8 kHz tick rate.

USB Hotplug:
- Replace timer-hook-driven polling (driver/timers/usbhotplug) with a
  dedicated 'usbd' daemon process that sleeps 1s between poll cycles.
- Add bounds check in usbcore.usb_check_hotplug for empty HC list.

Cleanup:
- Remove old scheduler unit (superseded by processmanager/contextswitcher).
- Remove tss unit and tss.init() call from kernel.
- Remove unused syslog import from contextswitcher.
- Reduce BASE_QUANTUM from 8 to 5.

.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
+# Cache liblvgl.a and source to host mount for next build
-echo "Copying LVGL source and objects to host mount..."
+echo "Caching LVGL to host mount..."
-mkdir /code/lvgl 2>/dev/null || true
+mkdir -p "$CACHE_DIR"
-rm -rf /code/lvgl/* /code/lvgl/.[!.]* /code/lvgl/..?* 2>/dev/null || true
+rm -rf ${CACHE_DIR}/* ${CACHE_DIR}/.[!.]* ${CACHE_DIR}/..?* 2>/dev/null || true
-cp -a "$LVGL_DIR/src" /code/lvgl/src
+cp "${OUT_DIR}/liblvgl.a" "${CACHE_DIR}/liblvgl.a"
-cp -a "$OBJ_DIR" /code/lvgl/obj
+cp -a "$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/contextswitcher.pas

@@ -12,15 +12,118 @@
 //  See the License for the specific language governing permissions and
 //  limitations under the License.
 
-{ 
+{
-	ContextSwitcher - Switch Process Contexts when preempted.
+    ContextSwitcher - Custom IRQ0 handler for preemptive context switching.
-	
+
-	@author(Kieron Morris <[email protected]>)
+    Replaces the default ISR_32 with a naked assembly stub that saves the
+    interrupted context (PUSHAD + segment regs), calls a Pascal helper to
+    dispatch timer hooks, send EOI, and run the scheduler, then restores
+    the next process context (or idles) via the returned ESP.
+
+    @author(Kieron Morris <[email protected]>)
 }
 unit contextswitcher;
 
+{$ASMMODE intel}
+
 interface
 
-implementation;
+uses
+    idt, isrmanager, processmanager, proctypes, util, tracer;
+
+{ Initialise: overwrite IDT gate 32 with our custom ISR. }
+procedure init;
+
+implementation
+
+{ -----------------------------------------------------------------------
+  do_context_switch_work
+  Pascal helper called from the assembly ISR.  Receives the current ESP
+  (pointing to the GS..EFLAGS save area), dispatches timer hooks, sends
+  EOI, runs the scheduler and returns the ESP for the next context.
+  Uses register calling convention: saved_esp in EAX, result in EAX.
+  ----------------------------------------------------------------------- }
+function do_context_switch_work(saved_esp : uint32) : uint32;
+var
+    next : PProcessContext;
+begin
+    { 1. Save ESP into the current process }
+    processmanager.CurrentProcess^.SavedESP := saved_esp;
+
+    { 2. Dispatch all hooks registered on interrupt 32 (timer hooks).
+         This fires TMR_0_ISR.Main which in turn fires BDA tick,
+         graphics refresh, USB hotplug, etc. }
+    isrmanager.dispatchHooks(32);
+
+    { 3. Send End-Of-Interrupt to the master PIC }
+    outb($20, $20);
+
+    { 4. Pick the next process to run (always returns non-nil; idle as fallback) }
+    next := processmanager.scheduler_pick_next;
+    processmanager.CurrentProcess := next;
+
+    { 5. Return the selected process ESP }
+    do_context_switch_work := next^.SavedESP;
+end;
+
+{ -----------------------------------------------------------------------
+  context_switch_isr
+  Naked assembly ISR that replaces ISR_32 (IRQ0 / PIT timer).
+
+  Stack on entry (pushed by CPU):
+      [ESP+8] EFLAGS
+      [ESP+4] CS
+      [ESP+0] EIP
+
+  We push general-purpose and segment registers, call the Pascal helper,
+  switch ESP to the returned value, pop registers and IRETD.
+  ----------------------------------------------------------------------- }
+procedure context_switch_isr; assembler; nostackframe;
+asm
+    { Save all general-purpose registers (EAX,ECX,EDX,EBX,ESP,EBP,ESI,EDI) }
+    pushad
+
+    { Save segment registers }
+    push ds
+    push es
+    push fs
+    push gs
+
+    { Load kernel data segments }
+    mov ax, $10
+    mov ds, ax
+    mov es, ax
+    mov fs, ax
+    mov gs, ax
+
+    { Call Pascal helper: EAX = current ESP (register calling convention).
+      Returns new ESP in EAX. }
+    mov eax, esp
+    call do_context_switch_work
+    mov esp, eax
+
+    { Restore segment registers }
+    pop gs
+    pop fs
+    pop es
+    pop ds
+
+    { Restore general-purpose registers }
+    popad
+
+    { Return from interrupt }
+    iretd
+end;
+
+{ -----------------------------------------------------------------------
+  init
+  Override IDT gate 32 with our custom ISR.  Must be called AFTER
+  isrmanager.init so that the default gate has been set up first.
+  ----------------------------------------------------------------------- }
+procedure init;
+begin
+    idt.set_gate(32, uint32(@context_switch_isr), $08, ISR_RING_0);
+    tracer.push_trace('contextswitcher.init');
+end;
 
 end.

src/cpu.pas

@@ -22,7 +22,7 @@ unit cpu;
 interface
 
 uses
-    util, RTC;
+    util, RTC, stdio;
 
 type
     PCapabilities_Old = ^TCapabilities_Old;
@@ -113,12 +113,10 @@ var
     CAP_OLD, CAP_NEW : uint32;
 
 procedure init();
+procedure Terminal_Command_CPU(Params : PParamList; stdin_buf, stdout_buf, stderr_buf : POutBuf);
 
 implementation
 
-uses
-    stdio;
-
 procedure getCPUIdentifier;
 var
     id0, id1, id2 : uint32;
@@ -325,7 +323,6 @@ end;
 
 procedure init();
 begin
-    stdio.registerCommand('CPU', @Terminal_Command_CPU, 'CPU Info.');
     CPUID.Capabilities0:= PCapabilities_Old(@CAP_OLD);
     CPUID.Capabilities1:= PCapabilities_New(@CAP_NEW); 
     getCPUIdentifier;

src/driver/bus/PCI.pas

@@ -18,7 +18,7 @@
 	@author(Aaron Hance <[email protected]>)
 	@author(Kieron Morris <[email protected]>)
 }
-unit PCI;
+unit pci;
 
 interface
 

src/driver/bus/usb/OHCI.pas

@@ -7,7 +7,7 @@
 
     @author(Kieron Morris <[email protected]>)
 }
-unit OHCI;
+unit ohci;
 
 interface
 
@@ -23,6 +23,7 @@ uses
     drivermanagement,
     usbtypes,
     usbcore,
+    isrmanager,
     lists,
     strings;
 
@@ -234,6 +235,7 @@ type
         EDBulk      : POHCI_ED;   { Head of bulk ED list }
         EDInterrupt : POHCI_ED;   { Dummy head for interrupt ED list }
         NumPorts    : uint8;      { Number of downstream ports }
+        PollBusy    : boolean;    { Re-entrancy guard for poll }
         PCIBus      : uint8;      { PCI address }
         PCISlot     : uint8;
         PCIFunc     : uint8;
@@ -1022,6 +1024,60 @@ begin
     end;
 end;
 
+{ ========================= Interrupt-Driven Completion ========================= }
+
+const
+    OHCI_MAX_INSTANCES = 4;
+
+var
+    OHCIInstances     : array[0..OHCI_MAX_INSTANCES-1] of PUSBHCDriver;
+    OHCIInstanceCount : uint32;
+
+{ ISR handler — registered on the PCI interrupt line. }
+procedure ohci_isr;
+var
+    i      : uint32;
+    hc     : PUSBHCDriver;
+    priv   : POHCI_PrivData;
+    intSts : uint32;
+begin
+    for i := 0 to OHCIInstanceCount - 1 do begin
+        hc := OHCIInstances[i];
+        if hc = nil then continue;
+        priv := POHCI_PrivData(hc^.PrivData);
+        if priv = nil then continue;
+
+        { Check if this controller has pending interrupt status }
+        intSts := ohci_read(priv^.MMIOBase, OHCI_REG_INTSTATUS);
+        if intSts = 0 then continue;
+
+        { Acknowledge interrupt status NOW to de-assert level-triggered PCI line.
+          Must happen before ohci_poll, because PollBusy guard may skip the
+          acknowledge inside poll — leaving the line asserted = interrupt storm. }
+        ohci_write(priv^.MMIOBase, OHCI_REG_INTSTATUS, intSts);
+
+        { Process completions (walks ED lists) }
+        ohci_poll(hc);
+
+        { Hotplug: if RootHubStatusChange, flag for deferred processing }
+        if ((intSts AND OHCI_INT_RHSC) <> 0) and hc^.HotplugArmed then
+            hc^.PortChangePending := true;
+    end;
+    usbcore.fire_completion_hooks;
+end;
+
+{ Enable hardware interrupts: WritebackDoneHead, RootHubStatusChange, UnrecoverableError + MIE. }
+procedure ohci_enable_interrupts(hc : PUSBHCDriver);
+var
+    priv : POHCI_PrivData;
+begin
+    if (hc = nil) or (hc^.PrivData = nil) then exit;
+    priv := POHCI_PrivData(hc^.PrivData);
+    ohci_write(priv^.MMIOBase, OHCI_REG_INTENABLE,
+        OHCI_INT_WDH OR OHCI_INT_RHSC OR OHCI_INT_UE OR OHCI_INT_MIE);
+    syslog.logln('OHCI', 'Hardware interrupts enabled.');
+end;
+
 procedure ohci_poll(hc : PUSBHCDriver);
 var
     priv     : POHCI_PrivData;
@@ -1038,6 +1094,11 @@ var
 begin
     if (hc = nil) or (hc^.PrivData = nil) then exit;
     priv := POHCI_PrivData(hc^.PrivData);
+
+    { Re-entrancy guard }
+    if priv^.PollBusy then exit;
+    priv^.PollBusy := true;
+
     base := priv^.MMIOBase;
 
     { Read and acknowledge interrupt status }
@@ -1107,6 +1168,7 @@ begin
             ed := nextED;
         end;
     end;
+    priv^.PollBusy := false;
 end;
 
 { ========================= Load / Init ========================= }
@@ -1124,6 +1186,7 @@ var
 begin
     push_trace('OHCI.load');
     load := false;
+    OHCIInstanceCount := 0;
 
     devices := PCI.getDeviceInfo($0C, $03, $10, count);
     syslog.log('OHCI', 'Found ');
@@ -1220,9 +1283,24 @@ begin
         hcEntry := usbcore.register_hc(@hc);
 
         { Scan ports for connected devices (use the stable pointer, not stack-local @hc) }
-        if hcEntry <> nil then
+        if hcEntry <> nil then begin
-            usbcore.scan_ports(hcEntry)
+            { Track instance for ISR dispatch }
-        else
+            if OHCIInstanceCount < OHCI_MAX_INSTANCES then begin
+                OHCIInstances[OHCIInstanceCount] := hcEntry;
+                inc(OHCIInstanceCount);
+            end;
+
+            { Register ISR on PCI interrupt line }
+            syslog.log('OHCI', 'Registering ISR on IRQ ');
+            syslog.writeintln(devices[i].interrupt_line);
+            isrmanager.registerISR(32 + devices[i].interrupt_line, @ohci_isr);
+
+            { Enable hardware interrupts }
+            ohci_enable_interrupts(hcEntry);
+
+            { Scan for connected devices }
+            usbcore.scan_ports(hcEntry);
+        end else
             syslog.logln('OHCI', 'Failed to register HC with USB core.');
 
         syslog.logln('OHCI', 'Controller initialized and registered.');

src/driver/bus/usb/UHCI.pas

@@ -6,7 +6,7 @@
 
     @author(Kieron Morris <[email protected]>)
 }
-unit UHCI;
+unit uhci;
 
 interface
 
@@ -22,6 +22,7 @@ uses
     drivermanagement,
     usbtypes,
     usbcore,
+    isrmanager,
     lists,
     strings;
 
@@ -154,6 +155,7 @@ type
         QHControl   : PUHCI_QH; { Queue Head for control transfers }
         QHBulk      : PUHCI_QH; { Queue Head for bulk transfers }
         QHInterrupt : PUHCI_QH; { Queue Head for interrupt transfers }
+        PollBusy    : boolean;  { Re-entrancy guard for poll }
         PCIBus      : uint8;    { PCI bus/slot/func for bus mastering }
         PCISlot     : uint8;
         PCIFunc     : uint8;
@@ -750,6 +752,56 @@ begin
     pop_trace;
 end;
 
+{ ========================= Interrupt-Driven Completion ========================= }
+
+const
+    UHCI_MAX_INSTANCES = 4;
+
+var
+    UHCIInstances     : array[0..UHCI_MAX_INSTANCES-1] of PUSBHCDriver;
+    UHCIInstanceCount : uint32;
+
+{ ISR handler — registered on the PCI interrupt line. }
+procedure uhci_isr;
+var
+    i      : uint32;
+    hc     : PUSBHCDriver;
+    priv   : PUHCI_PrivData;
+    status : uint16;
+begin
+    for i := 0 to UHCIInstanceCount - 1 do begin
+        hc := UHCIInstances[i];
+        if hc = nil then continue;
+        priv := PUHCI_PrivData(hc^.PrivData);
+        if priv = nil then continue;
+
+        { Check if this controller has pending interrupt status }
+        status := uhci_read16(priv^.IOBase, UHCI_REG_USBSTS);
+        if (status AND (UHCI_STS_USBINT OR UHCI_STS_ERROR)) = 0 then continue;
+
+        { Acknowledge interrupt status NOW to de-assert level-triggered PCI line.
+          Must happen before uhci_poll, because PollBusy guard may skip the
+          acknowledge inside poll — leaving the line asserted = interrupt storm. }
+        uhci_write16(priv^.IOBase, UHCI_REG_USBSTS, status AND (UHCI_STS_USBINT OR UHCI_STS_ERROR));
+
+        { Process completions (walks QH/TD chains) }
+        uhci_poll(hc);
+    end;
+    usbcore.fire_completion_hooks;
+end;
+
+{ Enable hardware interrupts: Interrupt-on-Complete, Short Packet, Timeout/CRC. }
+procedure uhci_enable_interrupts(hc : PUSBHCDriver);
+var
+    priv : PUHCI_PrivData;
+begin
+    if (hc = nil) or (hc^.PrivData = nil) then exit;
+    priv := PUHCI_PrivData(hc^.PrivData);
+    uhci_write16(priv^.IOBase, UHCI_REG_USBINTR,
+        UHCI_INTR_IOC OR UHCI_INTR_SP OR UHCI_INTR_TIMEOUT);
+    syslog.logln('UHCI', 'Hardware interrupts enabled.');
+end;
+
 { ========================= Poll / Completion ========================= }
 
 procedure uhci_poll(hc : PUSBHCDriver);
@@ -768,6 +820,10 @@ begin
     if (hc = nil) or (hc^.PrivData = nil) then exit;
     priv := PUHCI_PrivData(hc^.PrivData);
 
+    { Re-entrancy guard }
+    if priv^.PollBusy then exit;
+    priv^.PollBusy := true;
+
     { Read and clear status register }
     status := uhci_read16(priv^.IOBase, UHCI_REG_USBSTS);
     if (status AND (UHCI_STS_USBINT OR UHCI_STS_ERROR)) <> 0 then
@@ -841,6 +897,7 @@ begin
         end;
         qh := qh^.SWNext;
     end;
+    priv^.PollBusy := false;
 end;
 
 { ========================= Load / Init ========================= }
@@ -857,6 +914,7 @@ var
 begin
     push_trace('UHCI.load');
     load := false;
+    UHCIInstanceCount := 0;
 
     devices := PCI.getDeviceInfo($0C, $03, $00, count);
     syslog.log('UHCI', 'Found ');
@@ -945,9 +1003,24 @@ begin
         hcEntry := usbcore.register_hc(@hc);
 
         { Scan ports for connected devices (use the stable pointer, not stack-local @hc) }
-        if hcEntry <> nil then
+        if hcEntry <> nil then begin
-            usbcore.scan_ports(hcEntry)
+            { Track instance for ISR dispatch }
-        else
+            if UHCIInstanceCount < UHCI_MAX_INSTANCES then begin
+                UHCIInstances[UHCIInstanceCount] := hcEntry;
+                inc(UHCIInstanceCount);
+            end;
+
+            { Register ISR on PCI interrupt line }
+            syslog.log('UHCI', 'Registering ISR on IRQ ');
+            syslog.writeintln(devices[i].interrupt_line);
+            isrmanager.registerISR(32 + devices[i].interrupt_line, @uhci_isr);
+
+            { Enable hardware interrupts }
+            uhci_enable_interrupts(hcEntry);
+
+            { Scan for connected devices }
+            usbcore.scan_ports(hcEntry);
+        end else
             syslog.logln('UHCI', 'Failed to register HC with USB core.');
 
         syslog.logln('UHCI', 'Controller initialized and registered.');

src/driver/bus/usb/USB.pas

@@ -17,7 +17,7 @@
 	
 	@author(Kieron Morris <[email protected]>)
 }
-unit USB;
+unit usb;
 
 interface
 
@@ -35,6 +35,7 @@ uses
     usbhub,
     usb_keyboard,
     usb_mouse,
+    usb_storage,
     OHCI, UHCI, EHCI, XHCI;
 
 procedure init;
@@ -89,6 +90,9 @@ begin
     { Initialize HID class drivers }
     usb_keyboard.init;
     usb_mouse.init;
+
+    { Initialize storage class driver }
+    usb_storage.init;
     
     UHCI_ID.Bus:= biPCI;
     UHCI_ID.id0:= idANY;

src/driver/bus/usb/usbtypes.pas

@@ -217,6 +217,9 @@ type
     PUSBHCDriver = ^TUSBHCDriver;
     PUSBTransfer = ^TUSBTransfer;
 
+    { ---- Disconnect Callback ---- }
+    TUSBDisconnectCallback = procedure(dev : PUSBDevice);
+
     { ---- Transfer Request ---- }
 
     TUSBTransfer = record
@@ -246,6 +249,7 @@ type
         Endpoints    : array[0..USB_MAX_ENDPOINTS-1] of TUSBEndpoint;
         NumEndpoints : uint8;
         Configured   : boolean;
+        fnDisconnect : TUSBDisconnectCallback; { Called before device is freed on unplug }
     end;
 
     { ---- HC Driver Abstraction (Function Pointer Types) ---- }
@@ -269,6 +273,8 @@ type
         PrivData     : Pointer;     { HC-specific state }
         Devices      : PLinkedListBase; { List of PUSBDevice attached }
         NextAddress  : uint8;       { Next available USB address (1-127) }
+        PortChangePending : boolean; { Set by ISR when port status changes; processed in deferred context }
+        HotplugArmed : boolean;     { False during boot; set true after initial scan_ports to ignore spurious RHSC }
         { Operations }
         fnReset      : TUSBHCReset;
         fnStart      : TUSBHCStart;

src/driver/hid/ps2/ps2_keyboard.pas

@@ -32,32 +32,41 @@ uses
 
 procedure callback(scan_code : void);
 var
-    info : TKeyInfo;
+    info     : TKeyInfo;
+    raw      : uint8;
+    baseCode : uint8;
+    isBreak  : boolean;
 begin
-    info.SHIFT_DOWN := keyboard.is_shift;
+    raw := uint8(scan_code);
-    info.CTRL_DOWN  := keyboard.is_ctrl;
+
-    info.ALT_DOWN   := keyboard.is_alt;
+    { In PS/2 scancode set 1, bit 7 set = key release (break code) }
-    info.is_down_code := true;
+    isBreak  := (raw AND $80) <> 0;
+    baseCode := raw AND $7F;
+
+    { Update modifier state (use raw codes so both make/break are handled) }
+    if raw = 42  then keyboard.is_shift := true;
+    if raw = 170 then keyboard.is_shift := false;
+    if raw = 29  then keyboard.is_ctrl  := true;
+    if raw = 157 then keyboard.is_ctrl  := false;
+    if raw = 56  then keyboard.is_alt   := true;
+    if raw = 184 then keyboard.is_alt   := false;
+
+    info.SHIFT_DOWN    := keyboard.is_shift;
+    info.CTRL_DOWN     := keyboard.is_ctrl;
+    info.ALT_DOWN      := keyboard.is_alt;
+    info.is_down_code  := not isBreak;
 
     if keyboard.is_shift then begin
-        if key_matrix_shift[uint8(scan_code)].key_code <> 0 then begin
+        if key_matrix_shift[baseCode].key_code <> 0 then begin
-            info.key_code := key_matrix_shift[uint8(scan_code)].key_code;
+            info.key_code := key_matrix_shift[baseCode].key_code;
             keyboard.reportKeyEvent(info);
         end;
     end else begin
-        if key_matrix[uint8(scan_code)].key_code <> 0 then begin
+        if key_matrix[baseCode].key_code <> 0 then begin
-            info.key_code := key_matrix[uint8(scan_code)].key_code;
+            info.key_code := key_matrix[baseCode].key_code;
             keyboard.reportKeyEvent(info);
         end;
     end;
-
-    { Update modifier state }
-    if uint8(scan_code) = 42 then keyboard.is_shift := true;
-    if uint8(scan_code) = 170 then keyboard.is_shift := false;
-    if uint8(scan_code) = 29 then keyboard.is_ctrl := true;
-    if uint8(scan_code) = 157 then keyboard.is_ctrl := false;
-    if uint8(scan_code) = 56 then keyboard.is_alt := true;
-    if uint8(scan_code) = 184 then keyboard.is_alt := false;
 end;
 
 function load(ptr : void) : boolean;

src/driver/hid/ps2/ps2_mouse.pas

@@ -119,8 +119,12 @@ var
     x32, y32 : sint32;
     r : pchar;
 begin
+    { mouse_wait(0) checks OBF with a short timeout (100 iterations).
+      When it returns true, data is ready — read it directly with inb($60).
+      Do NOT call mouse_read here: it uses mouse_wait_long (100k iterations)
+      and would spin-block the ISR if the next packet byte hasn't arrived yet. }
     while mouse_wait(0) do begin
-        b := mouse_read;
+        b := inb($60);
         if Cycle = 0 then begin
             if (b AND $08) = $08 then begin
                 Mouse_Byte[Cycle] := b;