Refactored paging and system code to reflect unified kernel size info.

Kernel/include/Tier0/paging.h

@@ -84,7 +84,7 @@ void paging_kernel_initialize(u64 KernelVirtualStart, u64 KernelPhysicalStart, u
 
 // The temporary page is a page you can use to access some temporary physical
 // location. There is only one page, 4096 bytes large. Deal with it.
-void             paging_temp_page_setup(T_LOAD_CONTEXT *LoadContext);
+void             paging_temp_page_setup(void);
 const inline u64 paging_temp_page_get_virtual(void)
 {
     return 0xFFFFFFFF80000000 + 511 * 0x1000;

Kernel/include/Tier0/system.h

@@ -3,6 +3,8 @@
 
 #include "load_context.h"
 
+#define SYSTEM_KERNEL_VIRTUAL 0xFFFFFFFF80000000
+
 struct S_SYSTEM_MLTBT_MMAP {
     u32 Size;
     u64 Base;
@@ -102,7 +104,12 @@ typedef struct {
     
     // Just a guess...
     T_SYSTEM_INVALID_RAM InvalidMemoryAreas[256];
-    u8 NumInvalidAreas;    
+    u8 NumInvalidAreas;
+
+    // kernel code size and location
+    u64 KernelSize;
+    u64 KernelPhysicalStart;
+    u64 KernelVirtualStart;
 } T_SYSTEM_INFO;
 
 u64 system_cpuid(u32 Code);
@@ -112,4 +119,9 @@ u8 system_msr_available(void);
 u64 system_msr_get(u32 MSR);
 void system_msr_set(u32 MSR, u64 Data);
 
+// kernel load address, size and mapping
+u64 system_get_kernel_size(void);
+u64 system_get_kernel_physical_start(void);
+u64 system_get_kernel_virtual_start(void);
+
 #endif

Kernel/src/Tier0/kmain.c

@@ -65,9 +65,8 @@ void kmain(u32 LoadContextAddress)
     kprintf("[i] Loader physical: %x-%x.\n", LoadContext->LoaderPhysicalStart, LoadContext->LoaderPhysicalEnd);
     kprintf("[i] Kernel virtual:  %x-%x.\n", &_start, &_end);
 
-    paging_kernel_initialize((u64)&_start, LoadContext->KernelPhysicalStart, LoadContext->KernelPhysicalEnd - LoadContext->KernelPhysicalStart);
-    paging_temp_page_setup(LoadContext);
-    paging_minivmm_setup((u64)&_end, 0xFFFFFFFF80000000 + 511 * 0x1000);
+    paging_temp_page_setup();
+    paging_minivmm_setup((u64)&_end, SYSTEM_KERNEL_VIRTUAL + 511 * 0x1000);
     // Let's create a new kernel stack
     u64 StackVirtual = paging_minivmm_allocate();
     kprintf("[i] New kernel stack 0x%x\n", StackVirtual);

Kernel/src/Tier0/paging.c

@@ -2,15 +2,12 @@
 #include "Tier0/kstdio.h"
 #include "Tier0/kstdlib.h"
 #include "Tier0/panic.h"
+#include "Tier0/system.h"
 #include "types.h"
 
 struct {
     T_PAGING_TAB_ENTRY *TempPage; // For temp page mapping.
     u64 TempPageVirtual;
-
-    u64 KernelVirtualStart;
-    u64 KernelPhysicalStart;
-    u64 KernelSize;
 } g_KernelPaging;
 
 struct {
@@ -27,13 +24,15 @@ T_PAGING_ML4 *paging_get_ml4(void)
 	return (T_PAGING_ML4*)Address;
 }
 
-void paging_temp_page_setup(T_LOAD_CONTEXT *LoadContext)
+void paging_temp_page_setup(void)
 {
+    u64 KernelVirtualStart = system_get_kernel_virtual_start();
+    u64 KernelSize = system_get_kernel_size();
+
     // Try using page 511 (last) from kernel table
-    u64 PageVirtual = 0xFFFFFFFF80000000 + 511 * 4096;
+    u64 PageVirtual = KernelVirtualStart + 511 * 4096;
     u64 MaxMapped = 4096 * 512; // first 2Mib by loader
     
-    u64 KernelSize = LoadContext->KernelPhysicalEnd - LoadContext->KernelPhysicalStart;
     if (KernelSize >= MaxMapped)
         PANIC("Cannot set up temp page, kernel > 2Mib!");
     
@@ -78,13 +77,6 @@ void paging_temp_page_set_physical(u64 Physical)
     __asm__ volatile("invlpg %0" :: "m"(*(u64 *)g_KernelPaging.TempPageVirtual));
 }
 
-void paging_kernel_initialize(u64 KernelVirtualStart, u64 KernelPhysicalStart, u64 KernelSize)
-{
-    g_KernelPaging.KernelVirtualStart = KernelVirtualStart;
-    g_KernelPaging.KernelPhysicalStart = KernelPhysicalStart;
-    g_KernelPaging.KernelSize = KernelSize;
-}
-
 /*u8 paging_get_physical_ex(u64 Virtual, u64 *Physical, T_PAGING_ML4 *ML4)
 {
     if (Virtual < g_KernelPaging.KernelVirtualStart || Virtual > g_KernelPaging.KernelVirtualStart + g_KernelPaging.KernelSize)

Kernel/src/Tier0/system.c

@@ -51,6 +51,11 @@ void system_parse_load_context(T_LOAD_CONTEXT *LoadContext)
         g_SystemInfo.MemoryLower = (u64)((u8*)Header)[4];
         g_SystemInfo.MemoryUpper = (u64)((u8*)Header)[8];
     }
+
+    // Kernel location in memory
+    g_SystemInfo.KernelPhysicalStart = LoadContext->KernelPhysicalStart;
+    g_SystemInfo.KernelSize = LoadContext->KernelPhysicalEnd - LoadContext->KernelPhysicalStart;
+    g_SystemInfo.KernelVirtualStart = SYSTEM_KERNEL_VIRTUAL;
     
     // Bootloader name from Multiboot header
     if ((Flags >> 9) & 1)
@@ -202,3 +207,18 @@ void system_msr_set(u32 MSR, u64 Data)
 {
     __asm__ volatile("wrmsr" :: "a"((u32)(Data & 0xFFFFFFFF)), "d"((u32)(Data >> 32)), "c"(MSR));
 }
+
+u64 system_get_kernel_size(void)
+{
+    return g_SystemInfo.KernelSize;
+}
+
+u64 system_get_kernel_physical_start(void)
+{
+    return g_SystemInfo.KernelPhysicalStart;
+}
+
+u64 system_get_kernel_virtual_start(void)
+{
+    return g_SystemInfo.KernelVirtualStart;
+}