Making kernel Higher-Half

8 files changed, 104 insertions, 49 deletions

diff --git a/src/core/apic.cc b/src/core/apic.cc
index a93e54e..0663014 100644
--- a/src/core/apic.cc
+++ b/src/core/apic.cc
@@ -5,18 +5,17 @@
 #include "asm.hpp"
 #include "libs/stdio.hpp"
 
-extern u64* kpml4;
 char enable=0;
 #define APIC_LAPIC_ADDR 0xFEE00000
 #define APIC_IOAPIC_ADDR 0xFEC00000
 #define APIC_LAPIC_REG_SPURIOUS 0xF0
 
 void apic_enable(){
-    // Allocate APIC registers
-    paging_allocate_addr(kpml4, APIC_LAPIC_ADDR, APIC_LAPIC_ADDR, 
-    PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
-    paging_allocate_addr(kpml4, APIC_IOAPIC_ADDR, APIC_IOAPIC_ADDR, 
-    PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
+    // Allocate APIC registers    TODODODODOOD!!!!!
+   // paging_allocate_addr(kpml4, APIC_LAPIC_ADDR, APIC_LAPIC_ADDR, 
+    //PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
+    //paging_allocate_addr(kpml4, APIC_IOAPIC_ADDR, APIC_IOAPIC_ADDR, 
+    //PAGING_OPT_RW|PAGING_OPT_P|PAGING_OPT_PCD);
 
     // Configure APIC register location
     u32 h=APIC_LAPIC_ADDR>>32;
diff --git a/src/core/apic.hpp b/src/core/apic.hpp
index edfeaa3..a2670b3 100644
--- a/src/core/apic.hpp
+++ b/src/core/apic.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
 
-
+#include "include/boucane.hpp"
 
 void apic_enable();
\ No newline at end of file
diff --git a/src/core/gdt.S b/src/core/gdt.S
new file mode 100644
index 0000000..f928b3f
--- /dev/null
+++ b/src/core/gdt.S
@@ -0,0 +1,25 @@
+.code64
+
+gdt64:
+    gdt64_null:
+    .long 0
+    .long 0
+    gdt64_cs:
+    .long 0
+    .byte 0
+    .byte 0b10011100
+    .byte 0b00100000
+    .byte 0
+    gdt64_ds:
+    .long 0
+    .byte 0
+    .byte 0b10010010
+    .word 0
+gdtr:
+    .word . - gdt64 - 1
+    .quad gdt64
+
+.global load_gdt
+load_gdt:
+    lgdt (gdtr)
+    ret
diff --git a/src/core/idt.cc b/src/core/idt.cc
index a73d92c..25264b6 100644
--- a/src/core/idt.cc
+++ b/src/core/idt.cc
@@ -1,14 +1,16 @@
 #include "idt.hpp"
+#include "core/paging.hpp"
 #include "libs/string.hpp"
 
-IDT_REGISTER IDTR = {
-    IDT_GATE_SIZE*IDT_MAX_ENTRIES,
-    IDT_ADDR
-};
 
+u32 idt[IDT_MAX_ENTRIES][4] __attribute__((aligned(4096)));;
+IDT_REGISTER IDTR;
 extern u64 INT_DEFAULT,INT_0,INT_14,INT_KBD;
 
 void idt_enable_interrupt(void){
+    IDTR.base=((u64)idt);
+    IDTR.limit=sizeof(idt);
+
     IDT_DESCRIPTOR d;
     d.ign=0;
     d.ist=0;
@@ -25,7 +27,7 @@ void idt_enable_interrupt(void){
             d.offset=(u64)&INT_14;
             idt_write_descriptor(d, i);
         }
-        else if(i==60){ // Page fault
+        else if(i==60){ // Keyboard
             d.offset=(u64)&INT_KBD;
             idt_write_descriptor(d, i);
         }
@@ -34,12 +36,11 @@ void idt_enable_interrupt(void){
             idt_write_descriptor(d, i);
         }
     }
-
+   
     // Enable interrupts
     asm(
-        "lidt (IDTR)   \n\t"
-        "sti           \n\t"
-    );
+        "lidt (IDTR)  \n\t"
+        "sti          \n\t ");
 }
 
 void idt_write_descriptor(IDT_DESCRIPTOR desc, u16 index){
@@ -47,9 +48,8 @@ void idt_write_descriptor(IDT_DESCRIPTOR desc, u16 index){
     u32 desc32_63=desc.ist | desc.options | (desc.offset&0xFFFF0000);
     u32 desc64_95=desc.offset>>32;
     u32 desc96_127=desc.ign;
-    u32* dst=(u32*)(IDTR.base+index*IDT_GATE_SIZE);
-    *dst=desc0_31;
-    *(dst+1)=desc32_63;
-    *(dst+2)=desc64_95;
-    *(dst+3)=desc96_127;
+    idt[index][0]=desc0_31;
+    idt[index][1]=desc32_63;
+    idt[index][2]=desc64_95;
+    idt[index][3]=desc96_127;
 }
\ No newline at end of file
diff --git a/src/core/idt.hpp b/src/core/idt.hpp
index 2f2050d..1133ad1 100644
--- a/src/core/idt.hpp
+++ b/src/core/idt.hpp
@@ -5,7 +5,7 @@
 
 #define IDT_GATE_SIZE 16
 #define IDT_MAX_ENTRIES 200
-#define IDT_ADDR 0x200000
+#define IDT_ADDR 0
 
 #define IDT_OPT_P (1 << 15)
 #define IDT_OPT_TYPE_INT 0xE << 8
@@ -27,5 +27,8 @@ typedef struct IDT_DESCRIPTOR {
     u32 ign;
 } __attribute__((packed)) IDT_DESCRIPTOR;
 
+/// @brief 3 u32 per entry
+extern u32 idt[IDT_MAX_ENTRIES][4];
+
 void idt_enable_interrupt(void);
 void idt_write_descriptor(IDT_DESCRIPTOR desc, u16 index);
\ No newline at end of file
diff --git a/src/core/int.S b/src/core/int.S
index 1c8d7bb..daf0224 100644
--- a/src/core/int.S
+++ b/src/core/int.S
@@ -1,3 +1,5 @@
+.code64
+
 .extern printk
 .extern ack
 
@@ -40,4 +42,4 @@ MSG_INT_14:
 MSG_INT_KBD:
 .asciz "Key press!"
 MSG:
-.asciz "Called :)\n"
\ No newline at end of file
+.asciz "Called :)\n"
diff --git a/src/core/paging.cc b/src/core/paging.cc
index 8e58511..73a5c63 100644
--- a/src/core/paging.cc
+++ b/src/core/paging.cc
@@ -4,29 +4,50 @@
 #include "libs/string.hpp"
 
 char paging_status[PAGING_MAX_PAGE / 8];
-u64* kpml4;
+u64 kernel_vma,stack_pma,userspace_pma;
+u64 kpages[MAX_TABLES][512] __attribute__((aligned(4096)));
+int kpages_next=1; // First page is for the pml4
+
+u64* paging_allocate_table(){
+    u64 addr=(u64)kpages[kpages_next];
+    u64* allocated=(u64*)(addr-kernel_vma);
+    kpages_next++;
+    return allocated;
+}
 
 void paging_enable() {
+    // Init linker variables
+    asm("movq $__kernel_vma, %0":"=r"(kernel_vma));
+    asm("movq $__userspace_pma, %0":"=r"(userspace_pma));
+    asm("movq $__stack_pma, %0":"=r"(stack_pma));
+
     // Init status
     for (int i = 0; i < PAGING_MAX_PAGE / 8; i++) {
         paging_status[i] = 0;
     }
 
+    // Init tables
+    for(int i=0;i<MAX_TABLES;i++){
+        memset(kpages[i], 0, 512*64);
+    }
+ 
     // Allocate paging for the kernel (to not override the source
     // code during the next paging_allocate_table() calls)
-    paging_allocate_contiguous(PAGING_KERNEL_USED_PAGE);
+    paging_allocate_contiguous(userspace_pma/4096);
 
     // Setting up new kernel address space
-    kpml4=paging_allocate_table();
-    for(int i=0;i<PAGING_KERNEL_SPACE_MAX_PAGE;i++){
-        int addr=i*4096;
-        paging_allocate_addr(kpml4,addr,addr, PAGING_OPT_P|PAGING_OPT_RW); // Identity map
+    for(u64 i=0;i<=0x10000000;i+=4096){
+        paging_allocate_addr(kpages[0],kernel_vma+i,i, 0x3,0); // Identity map
     }
+    // 4096 bytes stack
+    paging_allocate_addr(kpages[0],kernel_vma-4096,stack_pma,0x3,0);
+
     // Load new pml4
+    u64 kpage_phy=((u64)kpages[0]-kernel_vma);
     asm volatile(
-        "movq %0, %%rax        \n\t"
-        "movq %%rax, %%cr3     \n\t"
-        :: "r" (kpml4));
+        "mov %0, %%rax        \n\t"
+        "mov %%rax, %%cr3     \n\t"
+        :: "r" (kpage_phy));
 }
 
 u64 paging_as_phy(u64* pml4_table, u64 virt){
@@ -40,6 +61,7 @@ u64 paging_as_phy(u64* pml4_table, u64 virt){
     u64* pt_table=(u64*)PAGE(pd_table[pd]);
     return((PAGE(pt_table[pt]))|(virt&0xFFF));
 }
+
 u64* paging_allocate_contiguous(int npages){
     int n_contiguous=0;
     for (int i = 0; i < PAGING_MAX_PAGE / 8; i++) {
@@ -116,12 +138,6 @@ void paging_dump(int min, int max) {
     }
 }
 
-u64* paging_allocate_table(){
-    u64* table=paging_allocate_contiguous(8);
-    memset(table, 0, 32768); // nb_entries * entry size = 512 * 64
-    return table;
-}
-
 void paging_deallocate_table(u64* table){
     char *c_table=(char*)PAGE((u64)table);
     for(u8 i=0;i<8;i++){
@@ -130,7 +146,7 @@ void paging_deallocate_table(u64* table){
     }
 }
 
-void paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options){
+void paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options, u64 offset){
     u16 pml4=virt>>39&0x1FF;
     u16 pdp=virt>>30&0x1FF;
     u16 pd=virt>>21&0x1FF;
@@ -141,27 +157,29 @@ void paging_allocate_addr(u64* pml4_table, u64 virt, u64 phy, u16 options){
     if(pml4_table[pml4] == 0){
         pml4_table[pml4]=(u64)paging_allocate_table();
         pml4_table[pml4]|=options;
-        paging_allocate_addr(pml4_table,virt,phy,options);
+        paging_allocate_addr(pml4_table,virt,phy,options,offset);
         return;
     }
+
     // Solve pd
-    u64* pdp_table=(u64*)PAGE(pml4_table[pml4]);
+    u64* pdp_table=(u64*)(PAGE(pml4_table[pml4])+offset);
     if(pdp_table[pdp] == 0){
         pdp_table[pdp]=(u64)paging_allocate_table();
         pdp_table[pdp]|=options;
-        paging_allocate_addr(pml4_table,virt,phy,options);
+        paging_allocate_addr(pml4_table,virt,phy,options,offset);
         return;
     }
+    
     // Solve pt
-    u64* pd_table=(u64*)PAGE(pdp_table[pdp]);
+    u64* pd_table=(u64*)(PAGE(pdp_table[pdp])+offset);
     if(pd_table[pd] == 0){
         pd_table[pd]=(u64)paging_allocate_table();
         pd_table[pd]|=options;
-        paging_allocate_addr(pml4_table,virt,phy,options);
+        paging_allocate_addr(pml4_table,virt,phy,options,offset);
         return;
     }
     // Solve address
-    u64* pt_table=(u64*)PAGE(pd_table[pd]);
+    u64* pt_table=(u64*)(PAGE(pd_table[pd])+offset);
     if(pt_table[pt] == 0){
         pt_table[pt]=PAGE(phy);
         pt_table[pt]|=options;
diff --git a/src/core/paging.hpp b/src/core/paging.hpp
index 4bb668c..089bd47 100644
--- a/src/core/paging.hpp
+++ b/src/core/paging.hpp
@@ -18,9 +18,14 @@
 
 /// @brief Get page address that contain addr
 #define PAGE(addr) (addr&(~(0xFFF)))
-#define PAGING_MAP(addr) paging_allocate_addr(kpml4,(u64)(addr),(u64)(addr),PAGING_OPT_P|PAGING_OPT_RW)
+#define PAGING_MAP(addr) paging_allocate_addr(kpages[0],(u64)(addr),(u64)(addr),PAGING_OPT_P|PAGING_OPT_RW,kernel_vma)
+#define MAX_TABLES 280
 
-extern u64* kpml4;
+/// @brief All PAE table structures are allocated here
+extern u64 kpages[MAX_TABLES][512];
+
+/// @brief Various variables from the linker
+extern u64 kernel_vma,stack_pma,userspace_pma;
 
 /**
  * Setup and enable PAE paging
@@ -56,13 +61,16 @@ void paging_deallocate_table(u64* table);
 /**
  * Allocate table structure (pml4, pdp etc..)
  */
-u64* paging_allocate_table();
+u64* paging_allocate_table_local();
 
 /**
  * Map virtual page associated to virt
  * to the physical page associated with phy
+ * Offset can be used to convert pml4_table address
+ * content to virtual addresses (since physical addresses from the pml4_table are not
+ * available after the trampoline into High-Half memory)
  */
-void paging_allocate_addr(u64* pml4_table,u64 virt, u64 phy, u16 options);
+void paging_allocate_addr(u64* pml4_table,u64 virt, u64 phy, u16 options, u64 offset);
 
 /**
  * Get associated physical address