feat(kernel): Architectural changes, and introducing a kKernelVM.

see code for more details.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

6 files changed, 67 insertions, 105 deletions

diff --git a/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc b/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc
index e4ad1024..ada2ee3f 100644
--- a/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc
+++ b/dev/kernel/HALKit/AMD64/HalApplicationProcessor.cc
@@ -113,27 +113,17 @@ EXTERN_C HAL::StackFramePtr mp_get_current_context(Int64 thrdid) {
 /// @param thrdid The thread ID.
 /***********************************************************************************/
 
-EXTERN_C BOOL mp_register_process(HAL::StackFramePtr stack_frame, ProcessID thrdid) {
+EXTERN_C BOOL mp_register_task(HAL::StackFramePtr stack_frame, ProcessID thrdid) {
   if (thrdid > kSMPCount) return NO;
 
-  if (!mp_is_smp()) {
-    if (stack_frame) {
-      kHWThread[thrdid].mFramePtr = stack_frame;
-      kHWThread[thrdid].mThreadID = thrdid;
-      HardwareThreadScheduler::The()[thrdid].Leak()->Busy(NO);
+  kHWThread[thrdid].mFramePtr = stack_frame;
+  kHWThread[thrdid].mThreadID = thrdid;
 
-      sched_jump_to_task(stack_frame);
+  HardwareThreadScheduler::The()[thrdid].Leak()->Busy(NO);
 
-      return YES;
-    }
-  } else {
-    kHWThread[thrdid].mFramePtr = stack_frame;
-    kHWThread[thrdid].mThreadID = thrdid;
-
-    return YES;
-  }
+  sched_jump_to_task(stack_frame);
 
-  return NO;
+  return YES;
 }
 
 /***********************************************************************************/
diff --git a/dev/kernel/HALKit/AMD64/HalCommonAPI.asm b/dev/kernel/HALKit/AMD64/HalCommonAPI.asm
index 230f50ed..d0ce2418 100644
--- a/dev/kernel/HALKit/AMD64/HalCommonAPI.asm
+++ b/dev/kernel/HALKit/AMD64/HalCommonAPI.asm
@@ -56,6 +56,8 @@ extern hal_system_call_enter
 global mp_system_call_handler
 
 mp_system_call_handler:
+    push rbp
+    mov  rbp, rsp
 
     push r8
     push r9
@@ -77,7 +79,9 @@ mp_system_call_handler:
     pop r9
     pop r8
 
-    o64 sysret
+    pop rbp
+
+    o64 iret
 
 
 section .text
@@ -88,12 +92,40 @@ sched_jump_to_task:
     push rbp
     mov  rbp, rsp
 
-    mov ax, 0x20
+    mov ax, 0x30
     mov ds, ax
     mov es, ax
     mov fs, ax
     mov gs, ax
 
+    mov ax, 0x18
+    ltr ax
+
+    push 0x30
+    mov rdx, [rcx + 0x08]
+    push rdx
+    o64 pushf
+    push 0x28
+    mov rdx, [rcx + 0x00]
+    push rdx
+
+    call sched_recover_registers
+
+    o64 iret
+
+global sched_idle_task
+
+sched_idle_task:
+    mov ax, cs
+    and ax, 3
+
+    jmp $
+    ret
+
+sched_recover_registers:
+    push rbp
+    mov  rbp, rsp
+
     mov  r8, [rcx + 0x10]
     mov  r9, [rcx + 0x18]
     mov r10, [rcx + 0x20]
@@ -103,14 +135,6 @@ sched_jump_to_task:
     mov r14, [rcx + 0x40]
     mov r15, [rcx + 0x48]
 
-    mov rax, [rcx + 0x00]
-    mov rsp, [rcx + 0x08]
-
-    o64 sysret
-    int 3 ;; Never continue here.
+    pop rbp
 
-global sched_idle_task
-
-sched_idle_task:
-    jmp $
-    ret
+    ret
\ No newline at end of file
diff --git a/dev/kernel/HALKit/AMD64/HalCoreInterruptHandlerAMD64.cc b/dev/kernel/HALKit/AMD64/HalCoreInterruptHandlerAMD64.cc
index 51fc4f0e..633adccb 100644
--- a/dev/kernel/HALKit/AMD64/HalCoreInterruptHandlerAMD64.cc
+++ b/dev/kernel/HALKit/AMD64/HalCoreInterruptHandlerAMD64.cc
@@ -37,14 +37,6 @@ EXTERN_C Kernel::Void idt_handle_gpf(Kernel::UIntPtr rsp) {
 
   auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
 
-  if (!process) {
-    ke_panic(RUNTIME_CHECK_BAD_BEHAVIOR, "General Access Fault.");
-  }
-  if (process.Leak().Signal.SignalID == SIGKILL || process.Leak().Signal.SignalID == SIGABRT ||
-      process.Leak().Signal.SignalID == SIGTRAP) {
-    dbg_break_point();
-  }
-
   Kernel::kout << "Kernel: General Access Fault.\r";
 
   process.Leak().Signal.SignalArg = rsp;
@@ -63,15 +55,6 @@ EXTERN_C void idt_handle_pf(Kernel::UIntPtr rsp) {
 
   auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
 
-  if (!process) {
-    ke_panic(RUNTIME_CHECK_BAD_BEHAVIOR, "Access Fault.");
-  }
-
-  if (process.Leak().Signal.SignalID == SIGKILL || process.Leak().Signal.SignalID == SIGABRT ||
-      process.Leak().Signal.SignalID == SIGTRAP) {
-    dbg_break_point();
-  }
-
   Kernel::kout << "Kernel: Page Fault.\r";
   Kernel::kout << "Kernel: SIGKILL\r";
 
@@ -104,14 +87,6 @@ EXTERN_C void idt_handle_math(Kernel::UIntPtr rsp) {
 
   auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
 
-  if (!process) {
-    ke_panic(RUNTIME_CHECK_BAD_BEHAVIOR, "Math Fault.");
-  }
-  if (process.Leak().Signal.SignalID == SIGKILL || process.Leak().Signal.SignalID == SIGABRT ||
-      process.Leak().Signal.SignalID == SIGTRAP) {
-    dbg_break_point();
-  }
-
   Kernel::kout << "Kernel: Math error (division by zero?).\r";
 
   process.Leak().Signal.SignalArg = rsp;
@@ -130,15 +105,6 @@ EXTERN_C void idt_handle_generic(Kernel::UIntPtr rsp) {
 
   auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
 
-  if (!process) {
-    ke_panic(RUNTIME_CHECK_BAD_BEHAVIOR, "Generic Fault.");
-  }
-
-  if (process.Leak().Signal.SignalID == SIGKILL || process.Leak().Signal.SignalID == SIGABRT ||
-      process.Leak().Signal.SignalID == SIGTRAP) {
-    dbg_break_point();
-  }
-
   (Void)(Kernel::kout << "Kernel: Process RSP: " << Kernel::hex_number(rsp) << Kernel::kendl);
   Kernel::kout << "Kernel: Access Process Fault.\r";
 
@@ -152,19 +118,9 @@ EXTERN_C void idt_handle_generic(Kernel::UIntPtr rsp) {
 }
 
 EXTERN_C Kernel::Void idt_handle_breakpoint(Kernel::UIntPtr rip) {
-  auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
-
-  if (!process) {
-    while (YES)
-      ;
-  }
-
   hal_idt_send_eoi(3);
 
-  if (process.Leak().Signal.SignalID == SIGKILL || process.Leak().Signal.SignalID == SIGABRT ||
-      process.Leak().Signal.SignalID == SIGTRAP) {
-    dbg_break_point();
-  }
+  auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
 
   (Void)(Kernel::kout << "Kernel: Process RIP: " << Kernel::hex_number(rip) << Kernel::kendl);
 
@@ -189,11 +145,6 @@ EXTERN_C void idt_handle_ud(Kernel::UIntPtr rsp) {
 
   auto& process = Kernel::UserProcessScheduler::The().TheCurrentProcess();
 
-  if (!process) {
-    while (YES)
-      ;
-  }
-
   if (process.Leak().Signal.SignalID == SIGKILL || process.Leak().Signal.SignalID == SIGABRT ||
       process.Leak().Signal.SignalID == SIGTRAP) {
     dbg_break_point();
diff --git a/dev/kernel/HALKit/AMD64/HalInterruptAPI.asm b/dev/kernel/HALKit/AMD64/HalInterruptAPI.asm
index a6b194d3..5e82f969 100644
--- a/dev/kernel/HALKit/AMD64/HalInterruptAPI.asm
+++ b/dev/kernel/HALKit/AMD64/HalInterruptAPI.asm
@@ -20,8 +20,6 @@ __NE_INT_%1:
 
     std
 
-    add rsp, 8
-
     o64 iret
 %endmacro
 
@@ -61,8 +59,6 @@ __NE_INT_0:
     
     std
 
-    add rsp, 8
-
     o64 iret
 
 __NE_INT_1:
@@ -83,8 +79,6 @@ __NE_INT_2:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 ;; @brief Triggers a breakpoint and freeze the process. RIP is also fetched.
@@ -96,8 +90,6 @@ __NE_INT_3:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 __NE_INT_4:
@@ -109,16 +101,12 @@ __NE_INT_4:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 __NE_INT_5:
     cld
     std
 
-    add rsp, 8
-
     o64 iret
 
 ;; Invalid opcode interrupt
@@ -130,8 +118,6 @@ __NE_INT_6:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 __NE_INT_7:
@@ -142,8 +128,6 @@ __NE_INT_7:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 ;; Invalid opcode interrupt
@@ -156,8 +140,6 @@ __NE_INT_8:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 IntNormal 9
@@ -187,8 +169,6 @@ __NE_INT_14:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 IntNormal 15
@@ -247,8 +227,6 @@ __NE_INT_40:
 
     std
 
-    add rsp, 8
-
     o64 iret
 
 IntNormal 41
diff --git a/dev/kernel/HALKit/AMD64/HalKernelMain.cc b/dev/kernel/HALKit/AMD64/HalKernelMain.cc
index 4de43f27..5394645a 100644
--- a/dev/kernel/HALKit/AMD64/HalKernelMain.cc
+++ b/dev/kernel/HALKit/AMD64/HalKernelMain.cc
@@ -38,9 +38,9 @@ EXTERN_C Int32 hal_init_platform(Kernel::HEL::BootInfoHeader* handover_hdr) {
   Boot::ExitBootServices(handover_hdr->f_HardwareTables.f_ImageKey,
                          handover_hdr->f_HardwareTables.f_ImageHandle);
 
-  kKernelCR3 = kHandoverHeader->f_PageStart;
+  kKernelVM = kHandoverHeader->f_PageStart;
 
-  hal_write_cr3(kKernelCR3);
+  hal_write_cr3(kKernelVM);
 
   /************************************** */
   /*     INITIALIZE BIT MAP.              */
@@ -54,7 +54,12 @@ EXTERN_C Int32 hal_init_platform(Kernel::HEL::BootInfoHeader* handover_hdr) {
   /*     INITIALIZE GDT AND SEGMENTS. */
   /************************************** */
 
-  STATIC CONST auto kGDTEntriesCount = 6;
+  STATIC CONST auto kGDTEntriesCount = 8;
+
+  STATIC HAL::Detail::NE_TSS kKernelTSS{};
+
+  kKernelTSS.fRsp0 = (UInt64) kHandoverHeader->f_StackTop;
+  kKernelTSS.fIopb = sizeof(HAL::Detail::NE_TSS);
 
   /* The GDT, mostly descriptors for user and kernel segments. */
   STATIC Kernel::HAL::Detail::NE_GDT_ENTRY ALIGN(0x08) kGDTArray[kGDTEntriesCount] = {
@@ -76,6 +81,8 @@ EXTERN_C Int32 hal_init_platform(Kernel::HEL::BootInfoHeader* handover_hdr) {
        .fAccessByte = 0x92,
        .fFlags      = 0xCF,
        .fBaseHigh   = 0},  // Kernel data
+      {},                // TSS data low
+      {},                // TSS data high
       {.fLimitLow   = 0x0,
        .fBaseLow    = 0,
        .fBaseMid    = 0,
@@ -90,6 +97,20 @@ EXTERN_C Int32 hal_init_platform(Kernel::HEL::BootInfoHeader* handover_hdr) {
        .fBaseHigh   = 0},  // User data
   };
 
+  kGDTArray[3].fLimitLow   = sizeof(HAL::Detail::NE_TSS) - 1;
+  kGDTArray[3].fBaseLow    = ((UIntPtr) &kKernelTSS) & 0xFFFF;
+  kGDTArray[3].fBaseMid    = (((UIntPtr) &kKernelTSS) >> 16) & 0xFF;
+  kGDTArray[3].fAccessByte = 0x89;  // Present, type 9 = 64-bit available TSS
+  kGDTArray[3].fFlags      = 0x20 | ((((UIntPtr) &kKernelTSS) >> 24) & 0x0F);
+  kGDTArray[3].fBaseHigh   = (((UIntPtr) &kKernelTSS) >> 24) & 0xFF;
+
+  kGDTArray[4].fLimitLow   = ((UIntPtr) &kKernelTSS >> 32) & 0xFFFF;
+  kGDTArray[4].fBaseLow    = 0;
+  kGDTArray[4].fBaseMid    = 0;
+  kGDTArray[4].fAccessByte = 0;
+  kGDTArray[4].fFlags      = 0;
+  kGDTArray[4].fBaseHigh   = 0;
+
   // Load memory descriptors.
   Kernel::HAL::Register64 gdt_reg;
 
diff --git a/dev/kernel/HALKit/AMD64/Processor.h b/dev/kernel/HALKit/AMD64/Processor.h
index c574f8d5..3bf0ad3e 100644
--- a/dev/kernel/HALKit/AMD64/Processor.h
+++ b/dev/kernel/HALKit/AMD64/Processor.h
@@ -285,6 +285,4 @@ EXTERN_C ATTRIBUTE(naked) Kernel::Void hal_load_gdt(Kernel::HAL::Register64 ptr)
 inline Kernel::VoidPtr kKernelBitMpStart = nullptr;
 inline Kernel::UIntPtr kKernelBitMpSize  = 0UL;
 
-inline Kernel::VoidPtr kKernelCR3 = nullptr;
-
 #endif  // __NE_AMD64__ */
\ No newline at end of file