[ IMP ] Many improvements and kernel changes.

Signed-off-by: Amlal El Mahrouss <amlal.elmahrouss@icloud.com>

8 files changed, 124 insertions, 63 deletions

diff --git a/dev/ZKA/HALKit/AMD64/HalDescriptorLoader.cxx b/dev/ZKA/HALKit/AMD64/HalDescriptorLoader.cxx
index 0033f614..9a0914f8 100644
--- a/dev/ZKA/HALKit/AMD64/HalDescriptorLoader.cxx
+++ b/dev/ZKA/HALKit/AMD64/HalDescriptorLoader.cxx
@@ -10,9 +10,6 @@ namespace Kernel::HAL
 {
 	namespace Detail
 	{
-		STATIC RegisterGDT kRegGdt;
-		STATIC HAL::Register64 kRegIdt;
-
 		STATIC ::Kernel::Detail::AMD64::InterruptDescriptorAMD64
 			kInterruptVectorTable[kKernelIdtSize];
 
@@ -41,10 +38,7 @@ namespace Kernel::HAL
 	/// @return
 	Void GDTLoader::Load(RegisterGDT& gdt)
 	{
-		Detail::kRegGdt.Base  = gdt.Base;
-		Detail::kRegGdt.Limit = gdt.Limit;
-
-		hal_load_gdt(Detail::kRegGdt);
+		hal_load_gdt(gdt);
 	}
 
 	Void IDTLoader::Load(Register64& idt)
@@ -81,11 +75,7 @@ namespace Kernel::HAL
 			Detail::kInterruptVectorTable[idt_indx].Zero = 0x0;
 		}
 
-		Detail::kRegIdt.Base  = reinterpret_cast<UIntPtr>(Detail::kInterruptVectorTable);
-		Detail::kRegIdt.Limit = sizeof(::Kernel::Detail::AMD64::InterruptDescriptorAMD64) *
-								(kKernelIdtSize - 1);
-
-		hal_load_idt(Detail::kRegIdt);
+		hal_load_idt(idt);
 
 		Detail::hal_remap_intel_pic_ctrl();
 	}
diff --git a/dev/ZKA/HALKit/AMD64/HalInterruptAPI.asm b/dev/ZKA/HALKit/AMD64/HalInterruptAPI.asm
index d3decfde..d59cc197 100644
--- a/dev/ZKA/HALKit/AMD64/HalInterruptAPI.asm
+++ b/dev/ZKA/HALKit/AMD64/HalInterruptAPI.asm
@@ -140,7 +140,14 @@ IntNormal 37
 IntNormal 38
 IntNormal 39
 IntNormal 40
-IntNormal 41
+
+extern mp_system_call_handler
+
+__ZKA_INT_41:
+    cmp rcx, 0
+    jne mp_system_call_handler
+    iretq
+
 IntNormal 42
 IntNormal 43
 IntNormal 44
@@ -218,7 +225,7 @@ hal_load_gdt:
     push 0x08
     lea rax, [rel rt_reload_segments]
     push rax
-    retfq
+    o64 retf
 rt_reload_segments:
     mov ax, 0x10
     mov ds, ax
diff --git a/dev/ZKA/HALKit/AMD64/HalKernelMain.cxx b/dev/ZKA/HALKit/AMD64/HalKernelMain.cxx
index d99431fa..2cdeb7f0 100644
--- a/dev/ZKA/HALKit/AMD64/HalKernelMain.cxx
+++ b/dev/ZKA/HALKit/AMD64/HalKernelMain.cxx
@@ -64,19 +64,35 @@ Kernel::Void hal_real_init(Kernel::Void) noexcept;
 EXTERN_C void hal_user_code_start(void);
 EXTERN_C Kernel::Void ke_dll_entrypoint(Kernel::Void);
 
+/* @brief TSS */
+
+Kernel::HAL::Detail::ZKA_TSS cTSS = {
+	.fReserved1 = 0x0,
+	.fRsp0 = 0x0,
+	.fRsp1 = 0x0,
+	.fRsp2 = 0x0,
+	.fReserved2 = 0x0,
+	.fIst1 = 0x0,
+	.fIst2 = 0x0,
+	.fIst3 = 0x0,
+	.fIst4 = 0x0,
+	.fIst5 = 0x0,
+	.fIst6 = 0x0,
+	.fIst7 = 0x0,
+	.fReserved3 = 0x0,
+	.fReserved4 = 0x0,
+	.fIopb = 0x0,
+};
 
 /* GDT, mostly descriptors for user and kernel segments. */
-STATIC Kernel::HAL::Detail::ZKA_GDT_ENTRY cGdt[9] = {
+STATIC Kernel::HAL::Detail::ZKA_GDT_ENTRY cGdt[6] = {
 	{.fLimitLow = 0, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x00, .fFlags = 0x00, .fBaseHigh = 0},		// Null entry
 	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x9A, .fFlags = 0xA0, .fBaseHigh = 0}, // Kernel code
 	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x92, .fFlags = 0xA0, .fBaseHigh = 0}, // Kernel data
 	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0xFA, .fFlags = 0xA0, .fBaseHigh = 0}, // User code
 	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0xF2, .fFlags = 0xA0, .fBaseHigh = 0}, // User data
 	// reserve them for later.
-	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x00, .fFlags = 0x00, .fBaseHigh = 0}, // User data
-	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x00, .fFlags = 0x00, .fBaseHigh = 0}, // User data
-	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x00, .fFlags = 0x00, .fBaseHigh = 0}, // User data
-	{.fLimitLow = 0xFFFF, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x00, .fFlags = 0x00, .fBaseHigh = 0}, // User data
+	{.fLimitLow = 0, .fBaseLow = 0, .fBaseMid = 0, .fAccessByte = 0x00, .fFlags = 0x00, .fBaseHigh = 0},
 };
 
 EXTERN_C void hal_init_platform(
@@ -117,7 +133,7 @@ Kernel::Void hal_real_init(Kernel::Void) noexcept
 	Kernel::HAL::RegisterGDT gdtBase;
 
 	gdtBase.Base  = reinterpret_cast<Kernel::UIntPtr>(cGdt);
-	gdtBase.Limit = (sizeof(Kernel::HAL::Detail::ZKA_GDT_ENTRY) * 9);
+	gdtBase.Limit = (sizeof(Kernel::HAL::Detail::ZKA_GDT_ENTRY) * 6) - 1;
 
 	CONST Kernel::HAL::GDTLoader cGDT;
 	cGDT.Load(gdtBase);
@@ -126,7 +142,8 @@ Kernel::Void hal_real_init(Kernel::Void) noexcept
 
 	Kernel::HAL::Register64 idtBase;
 	idtBase.Base  = (Kernel::UIntPtr)kInterruptVectorTable;
-	idtBase.Limit = 0;
+	idtBase.Limit = sizeof(::Kernel::Detail::AMD64::InterruptDescriptorAMD64) *
+								(kKernelIdtSize - 1);
 
 	CONST Kernel::HAL::IDTLoader cIDT;
 	cIDT.Load(idtBase);
diff --git a/dev/ZKA/HALKit/AMD64/HalMPContextSwitch.asm b/dev/ZKA/HALKit/AMD64/HalMPContextSwitch.asm
index ac68dfad..dc534589 100644
--- a/dev/ZKA/HALKit/AMD64/HalMPContextSwitch.asm
+++ b/dev/ZKA/HALKit/AMD64/HalMPContextSwitch.asm
@@ -21,6 +21,9 @@ section .text
 ;; rcx: code ptr.
 ;; rdx: stack ptr.
 mp_do_context_switch:
+    mov rsp, rdx
+    mov rbp, rsp
+
     mov r9,  [r8 + (8 * 2)]
     mov r10, [r8 + (8 * 3)]
     mov fs, [r8 + (8 * 4)]
@@ -31,11 +34,11 @@ mp_do_context_switch:
     mov gs, [r8 + (8 * 9)]
     mov r8,  [r8]
 
+    mov rax, rcx
+
     mov r11, 0x202
-    mov rsp, rdx
 
-    xor rax, rax
-	o64 sysret
+    o64 sysret
 
 ;; @brief Gets the current stack frame.
 mp_get_current_context:
@@ -43,35 +46,41 @@ mp_get_current_context:
     ret
 
 extern hal_system_call_enter
+global mp_system_call_handler
 
 mp_system_call_handler:
+    swapgs
+
     push r8
     push r9
     push r10
 
-    call hal_system_call_enter
+    jmp hal_system_call_enter
 
     pop r10
     pop r9
     pop r8
 
-    sysret
+    swapgs
+    sti
+
+    o64 sysret
 
 mp_do_context_switch_pre:
+	mov rcx, 0xc0000080
+	rdmsr
+	or eax, 1
+	wrmsr
 
-    xor rdx, rdx
-	mov rax, 0x202
-	mov rcx, 0xc0000084
+	mov rcx, 0xc0000081
+	rdmsr
+    mov rax, 0x00000000
+	mov edx, 0x00180008
 	wrmsr
-    xor rax, rax
-	mov rax, mp_system_call_handler
-    mov rdx, rax
-    shr rdx, 32
+
 	mov rcx, 0xc0000082
-	wrmsr
-    xor rax, rax
-	mov rdx, 0x230008
-    mov rcx, 0xc0000081
+	mov rax, mp_system_call_handler
+	mov rdx, 0x0
 	wrmsr
 
     ret
diff --git a/dev/ZKA/HALKit/AMD64/HalPageAlloc.cxx b/dev/ZKA/HALKit/AMD64/HalPageAlloc.cxx
index 3d8deac2..28b5f9be 100644
--- a/dev/ZKA/HALKit/AMD64/HalPageAlloc.cxx
+++ b/dev/ZKA/HALKit/AMD64/HalPageAlloc.cxx
@@ -98,11 +98,9 @@ namespace Kernel
 			kAllocationInProgress = false;
 
 			VoidPtr result = reinterpret_cast<VoidPtr>(vmh_header + sizeof(Detail::VIRTUAL_MEMORY_HEADER));
-			VoidPtr cr3 = hal_read_cr3();
 
-			mm_update_pte(cr3, 0, result, eFlagsPresent | (rw ? eFlagsRw : 0) | (user ? eFlagsUser : 0));
-			mm_update_pte(cr3, 0, result, (rw ? eFlagsRw : 0));
-			mm_update_pte(cr3, 0, result, (user ? eFlagsUser : 0));
+			mm_update_pte(result, (rw ? eFlagsRw : 0));
+			mm_update_pte(result, (user ? eFlagsUser : 0));
 
 			return result;
 		}
diff --git a/dev/ZKA/HALKit/AMD64/HalProcessor.cxx b/dev/ZKA/HALKit/AMD64/HalProcessor.cxx
index 94d989e7..169c02f5 100644
--- a/dev/ZKA/HALKit/AMD64/HalProcessor.cxx
+++ b/dev/ZKA/HALKit/AMD64/HalProcessor.cxx
@@ -16,25 +16,38 @@
 
 namespace Kernel::HAL
 {
-	EXTERN_C Int32 mm_update_pte(VoidPtr pd_base, VoidPtr phys_addr, VoidPtr virt_addr, UInt32 flags)
+	EXTERN_C Int32 mm_update_pte(VoidPtr virt_addr, UInt32 flags)
 	{
-		UIntPtr pte_idx = (UIntPtr)virt_addr >> 12;
+		VoidPtr pml4_base = hal_read_cr3();
 
-		volatile PTE* pte = (volatile PTE*)((UIntPtr)pd_base + (kPTEAlign * pte_idx));
+		UIntPtr pml4_idx = ((UIntPtr)virt_addr >> 39) & 0x1FFF;
+		UIntPtr pdpt_idx = ((UIntPtr)virt_addr >> 30) & 0x1FFF;
+		UIntPtr pd_idx	 = ((UIntPtr)virt_addr >> 21) & 0x1FFF;
+		UIntPtr pte_idx	 = ((UIntPtr)virt_addr >> 12) & 0x1FFF;
 
-		if (pte)
+		// Access PML4 entry
+		volatile UInt64* pml4_entry = (volatile UInt64*)(pml4_base + pml4_idx * sizeof(UIntPtr));
+		UInt64		   pdpt_base  = *pml4_entry & ~0xFFF; // Remove flags (assuming 4KB pages)
+
+		// Access PDPT entry
+		volatile UInt64* pdpt_entry = (volatile UInt64*)(pdpt_base + pdpt_idx * sizeof(UIntPtr));
+		UInt64		   pd_base	  = *pdpt_entry & ~0xFFF; // Remove flags
+
+		volatile UInt64* pd_entry = (volatile UInt64*)(pd_base + pd_idx * sizeof(UIntPtr));
+		UInt64			 pt_base  = *pd_entry & ~0xFFF; // Remove flags
+
+		volatile UInt64* page_addr = (volatile UInt64*)((UIntPtr)pt_base + (pte_idx * sizeof(UIntPtr)));
+
+		if (page_addr)
 		{
 			if (flags & eFlagsPresent)
-				pte->Present = flags & eFlagsPresent;
+				*page_addr |= 0x01; // present bit
 
 			if (flags & eFlagsRw)
-				pte->Rw = flags & eFlagsRw;
+				*page_addr |= 0x02;
 
 			if (flags & eFlagsUser)
-				pte->User = flags & eFlagsUser;
-
-			if (flags & eFlagsExecDisable)
-				pte->ExecDisable = flags & eFlagsExecDisable;
+				*page_addr |= 0x02;
 
 			return Yes;
 		}
diff --git a/dev/ZKA/HALKit/AMD64/HalSchedulerCore.cxx b/dev/ZKA/HALKit/AMD64/HalSchedulerCore.cxx
index 7b1f1711..bf98d01d 100644
--- a/dev/ZKA/HALKit/AMD64/HalSchedulerCore.cxx
+++ b/dev/ZKA/HALKit/AMD64/HalSchedulerCore.cxx
@@ -14,14 +14,24 @@ Void UserProcess::SetImageStart(VoidPtr imageStart) noexcept
 	if (imageStart == nullptr)
 		this->Crash();
 
-	HAL::mm_update_pte(hal_read_cr3(), 0, imageStart, HAL::eFlagsPresent | HAL::eFlagsUser);
+	HAL::mm_update_pte(imageStart, HAL::eFlagsPresent | HAL::eFlagsUser);
 
 	this->Image = imageStart;
 }
 
 namespace Kernel
 {
-	bool hal_check_stack(HAL::StackFramePtr stack_ptr)
+	/***********************************************************************************/
+	/// @brief Unimplemented function (crashes by default)
+	/// @param
+	/***********************************************************************************/
+
+	EXTERN_C Void __zka_pure_call(void)
+	{
+		asm volatile ("mov %r8, 0; mov %r9, 1; syscall");
+	}
+
+	Bool hal_check_stack(HAL::StackFramePtr stack_ptr)
 	{
 		if (!stack_ptr)
 			return false;
diff --git a/dev/ZKA/HALKit/AMD64/Processor.hxx b/dev/ZKA/HALKit/AMD64/Processor.hxx
index 911af46e..0f24a2be 100644
--- a/dev/ZKA/HALKit/AMD64/Processor.hxx
+++ b/dev/ZKA/HALKit/AMD64/Processor.hxx
@@ -24,16 +24,16 @@ EXTERN_C
 #include <cpuid.h>
 }
 
-#define kSyscallRoute (51)
+#define kSyscallRoute (0x29)
 
 #define IsActiveLow(FLG)	  (FLG & 2)
 #define IsLevelTriggered(FLG) (FLG & 8)
 
-#define kInterruptGate		 (0x8E)
-#define kTrapGate			 (0xEF)
-#define kTaskGate			 (0b10001100)
-#define kGdtKernelCodeSelector	 (0x08)
-#define kGdtUserCodeSelector (0x23)
+#define kInterruptGate		   (0x8E)
+#define kTrapGate			   (0xEF)
+#define kTaskGate			   (0b10001100)
+#define kGdtKernelCodeSelector (0x08)
+#define kGdtUserCodeSelector   (0x23)
 
 namespace Kernel
 {
@@ -62,16 +62,13 @@ namespace Kernel::HAL
 		eFlagsUser,
 		eFlagsRw,
 		eFlagsExecDisable,
-		eFlagsSetPhysAddress,
 		eFlagsCount,
 	};
 
 	/// @brief Updates a PTE from pd_base.
-	/// @param pd_base a valid PDE address.
-	/// @param phys_addr a valid phyiscal address.
 	/// @param virt_addr a valid virtual address.
 	/// @param flags the flags to put on the page.
-	EXTERN_C Int32 mm_update_pte(VoidPtr pd_base, VoidPtr phys_addr, VoidPtr virt_addr, UInt32 flags);
+	EXTERN_C Int32 mm_update_pte(VoidPtr virt_addr, UInt32 flags);
 
 	EXTERN_C UChar	In8(UInt16 port);
 	EXTERN_C UShort In16(UInt16 port);
@@ -230,6 +227,26 @@ namespace Kernel::HAL
 	/// @brief Processor specific namespace.
 	namespace Detail
 	{
+		/* @brief TSS struct. */
+		struct ZKA_TSS final
+		{
+			UInt32 fReserved1;
+			UInt64 fRsp0;
+			UInt64 fRsp1;
+			UInt64 fRsp2;
+			UInt64 fReserved2;
+			UInt64 fIst1;
+			UInt64 fIst2;
+			UInt64 fIst3;
+			UInt64 fIst4;
+			UInt64 fIst5;
+			UInt64 fIst6;
+			UInt64 fIst7;
+			UInt64 fReserved3;
+			UInt16 fReserved4;
+			UInt16 fIopb;
+		};
+
 		/**
 		  @brief Global descriptor table entry, either null, code or data.
 		*/