started a bit of paging for x64

kernel/arch/x86/paging.cpp

@@ -2,6 +2,7 @@
 #include <base.hpp>
 extern int kernel_start;
 extern int kernel_end;
+pagedir global_kernel[256];
 paging_context_x86::paging_context_x86(): paging_context() {
     *pmm >> pagedir_addr;
     if(context_enabled) {
@@ -175,12 +176,24 @@ paging_context_x86::~paging_context_x86() {
 }
 
 void paging_context_x86::switch_context() {
+    pagedir* p = (pagedir*)pagedir_addr;
+    if(context_enabled)
+        p=(pagedir*)0x400000;
+    for(int i = 0; i < 256; i++) {
+        global_kernel[i]=p[i];
+    }
     asm volatile("mov %0, %%cr3" :: "r"(pagedir_addr) : "memory");
     if(!context_enabled) {
         uint32_t cr0;
         asm volatile("mov %%cr0, %0" : "=r"(cr0));
         cr0 |= (1<<31);
         asm volatile("mov %0, %%cr0" :: "r"(cr0) : "memory");
+    } else {
+        for(int i=0;i<256;i++)
+            if((i>=1)&&(i<=3))
+                continue;
+            else
+                p[i]=global_kernel[i];
     }
     paging_context::switch_context();
 }

kernel/arch/x86_64/include/paging.h

@@ -0,0 +1,91 @@
+#pragma once
+#include <stdint.h>
+#include <pmm.hpp>
+#include <regs.h>
+#include <paging.hpp>
+typedef phys_t virt_t;
+struct pagemap_tbl {
+    bool active:1;
+    bool writable:1;
+    bool unprivileged:1;
+    bool no_write_cache:1;
+    bool no_read_cache:1;
+    bool accessed:1;
+    uint8_t sbz:3;
+    uint8_t ignored:3;
+    phys_t pagemap:40;
+    uint16_t ignored2:11;
+    bool executable:1;
+
+}__attribute__((packed));
+static_assert(sizeof(pagemap_tbl)==8);
+
+struct pagemap {
+    bool active:1;
+    bool writable:1;
+    bool unprivileged:1;
+    bool no_write_cache:1;
+    bool no_read_cache:1;
+    bool accessed:1;
+    bool sbz:1;
+    bool _1G_page:1;
+    bool global:1;
+    uint8_t ignored:3;
+    phys_t pagedir:40;
+    uint16_t ignored2:11;
+    bool executable:1;
+}__attribute__((packed));
+static_assert(sizeof(pagemap)==8);
+
+struct pagedir {
+    bool active:1;
+    bool writeable:1;
+    bool privileged:1;
+    bool no_write_cache:1;
+    bool no_read_cache:1;
+    bool accessed:1;
+    bool sbz:1;
+    bool _2M_page:1;
+    bool global:1;
+    uint8_t ignored:3;
+    phys_t pagetbl:40;
+    uint16_t ignored2:11;
+    bool executable:1;
+}__attribute__((packed));
+static_assert(sizeof(pagedir)==8);
+
+struct pagetbl {
+    bool active:1;
+    bool writeable:1;
+    bool privileged:1;
+    bool no_write_cache:1;
+    bool no_read_cache:1;
+    bool accessed:1;
+    bool sbz:1;
+    bool pat:1;
+    bool global:1;
+    uint8_t ignored:2;
+    bool lazy:1;
+    phys_t page:40;
+    uint16_t ignored2:11;
+    bool executable:1;
+}
+}__attribute__((packed));
+
+
+struct paging_context_x86: public paging_context {
+    phys_t pagemaptbl_addr;
+    paging_context_x86();
+    virtual ~paging_context_x86();
+    virtual void switch_context();
+    virtual void map_pagetable(struct paging_context *);
+    virtual void *mmap(phys_t addr, void *dest, protection prot=protection::RW, bool lazy=true);
+    virtual void munmap(void *addr);
+    virtual bool is_mapped(void *addr);
+    virtual void mprotect(void *addr, protection prot);
+    virtual bool has_no_exec();
+    virtual void *get_exception_address(cpu_state *cpu);
+    virtual bool lazymap(void *addr, cpu_state *cpu);
+    pagedir * operator*();
+    pagetbl * operator[](phys_t);
+};

kernel/arch/x86_64/paging.cpp

@@ -0,0 +1,30 @@
+#include <paging.h>
+#include <base.hpp>
+extern int kernel_start;
+extern int kernel_end;
+
+
+
+paging_context_x86::paging_context_x86(): paging_context() {
+    *pmm >> pagedir_addr;
+    if(context_enabled) {
+        current_context->mmap(pagedir_addr, (void*)0x800000, protection::RW, false);
+        pagemap *src=(pagemap *)0x400000;
+        pagemap *dest=(pagedir*)0x600000;
+        for(int i=0;i<256;i++)
+            dest[i]=src[i];
+        for(int i=256;i<512;i++)
+            dest[i].active=false;
+        dest[0].active=false;
+        phys_t first_pagedir;
+        *pmm >> first_pagedir;
+        dest[0].pagetable = first_pagedir >> 12;
+        dest[0].writeable=true;
+        dest[0].unprivileged=false;
+        dest[0].no_write_cache=true;
+        dest[0].no_read_cache=false;
+        dest[0].sbz=0;
+        dest[0].active=true;
+
+    }
+}

kernel/arch/x86_64/pc/start.cpp

@@ -17,9 +17,12 @@ CGATerm term;
 VESAfb term(mb_info);
 #endif
 PMM_MB lpmm(mb_info);
+
+#include<paging.hpp>
 void main();
 extern "C" void start(int eax, multiboot_info_t *ebx) {
     mb_info = ebx;
+    context_enabled=false;
     main();
 }
 void drivers_init() {

kernel/hw/pmm/pmm.cpp

@@ -58,7 +58,7 @@ union MMAPTag {
         uint8_t id;
         uint8_t size;
         uint8_t value;
-    }__attribute__((packed)) BITS;
+    }__attribute__((packed)) BITSi;
     struct {
         uint8_t id;
         uint8_t size;
@@ -108,7 +108,7 @@ PMM_MMAP::PMM_MMAP(): PMM(0x1000) {
                     ;
                 break;
             case 4:
-                bits = tag.BITS.value;
+                bits = tag.BITSi.value;
                 break;
             case 5:
                 if(tag.REGION.permission != PERM::RWX)

kernel/src/include/base.hpp

@@ -21,3 +21,9 @@ extern "C" void panic(const char* s);
 #define __BIG_ENDIAN__
 #endif
 #endif
+
+#ifdef __x86_64__
+#define BITS 64
+#else
+#define BITS 32
+#endif

kernel/src/include/pmm.hpp

@@ -1,10 +1,14 @@
 #pragma once
 #include <stdint.h>
 #include <stddef.h>
+class PMM;
+#include <base.hpp>
 typedef uintptr_t phys_t; ///< Type used for physical addresses
 /**
  * A single entry in the PMM list
  */
+
+#if BITS == 32
 /**
  * Physical memory manager. It stores the free memory in a linked list
  */
@@ -26,6 +30,34 @@ class PMM {
         virtual auto operator&&(phys_t page) -> bool; //Returns true if this page is free. O(1).
         virtual auto setUsed(phys_t page) -> void; //Marks a page as used. O(1).
 };
+
+#else
+
+struct pmm_entry {
+    phys_t next;
+    phys_t last;
+};
+
+class PMM {
+    protected:
+        phys_t head;
+        virtual auto isFree(phys_t address) -> bool;
+        auto fill() -> void;
+        phys_t page_size, lowest_page, highest_page;
+        void push(phys_t);
+        phys_t pop();
+    public:
+        PMM(phys_t page_size);
+        virtual ~PMM();
+        virtual auto operator<<(phys_t page) -> PMM &;
+        virtual auto operator>>(phys_t &page) -> PMM &;
+        virtual auto operator,(size_t no_pages) -> phys_t;
+        virtual auto operator()(phys_t pages, size_t no_pages) -> void;
+        virtual auto operator&&(phys_t page) -> bool;
+        virtual auto setUsed(phys_t page) -> void;
+};
+
+#endif
 /**
  * This definition is for having a python-like syntax - like `page in pmm`
  */

kernel/src/pmm.cpp

@@ -1,131 +1,7 @@
 #include <base.hpp>
-#include <pmm.hpp>
-extern "C" int kernel_start;
-extern "C" int kernel_end;
 
-
-uint32_t pmm_bitmap[32768];
-
-
-auto PMM::isFree(phys_t addr) -> bool {
-    if(addr == 0)
-        return false;
-    phys_t start = (phys_t)(&kernel_start);
-    phys_t end = (phys_t)(&kernel_end);
-    if((addr >= start) && (addr < end))
-        return false;
-    return true;
-}
-PMM::PMM(phys_t page_size): page_size(page_size), first_free(0), lowest_page(~0), highest_page(0) {
-    for(int i=0;i<32768;i++) {
-        pmm_bitmap[i]=0;
-    }
-    pmm = this;
-}
-void PMM::fill() {
-    for(phys_t i=highest_page; i>=lowest_page && i; i-=page_size) {
-        if(isFree(i))
-            *this << i;
-    }
-}
-PMM::~PMM() {}
-
-auto PMM::operator<<(phys_t page) -> PMM & {
-    (*this)(page,1);
-    return *this;
-}
-auto PMM::operator>>(phys_t &page) -> PMM & {
-    page = (*this, 1);
-    return *this;
-}
-
-auto PMM::operator,(size_t no_pages) -> phys_t {
-    if(first_free > highest_page)
-        panic("No free physical memory is available.");
-    if(no_pages == 1) {
-        while(!(first_free in *this)) {
-            first_free += page_size;
-            if(first_free > highest_page)
-                panic("No free physical memory is available.");
-        }
-        phys_t pageno = first_free / page_size;
-        phys_t index = pageno >> 5;
-        phys_t bit = pageno & 31;
-        pmm_bitmap[index] &= ~(1<<bit);
-        auto x = first_free;
-        first_free += page_size;
-        return x;
-    }
-    //Now we need to find a free page with n-1 free pages after it
-    phys_t linear_start = first_free;
-    phys_t length = (no_pages-1) * page_size;
-    while(true) {
-        bool found=true;
-        while(!(linear_start in *this)) {
-            linear_start += page_size;
-            if((linear_start > highest_page)||(linear_start+length > highest_page))
-                panic("No free physical memory is available.");
-        }
-        if(!((linear_start + length) in *this)) {
-            linear_start += no_pages * page_size;
-        }
-        //We're on to something
-        phys_t i;
-        for(i=linear_start; i < linear_start + length; i+=page_size) {
-            if(!(i in *this)) {
-                found=false;
-                break;
-            }
-        }
-        if(!found) {
-            linear_start=i+page_size;
-            continue;
-        }
-        //Set the first_free variable correctly when the first page was a hit
-        if(linear_start == first_free)
-            first_free += length + page_size;
-
-        phys_t pageno = linear_start / page_size;
-
-        for(i=linear_start; i <= linear_start + length; i+= page_size) {
-            phys_t index = pageno >> 5;
-            phys_t bit = pageno & 31;
-            pmm_bitmap[index] &= ~(1<<bit);
-            pageno++;
-        }
-        return linear_start;
-    }
-
-}
-auto PMM::operator()(phys_t pages, size_t no_pages) -> void {
-    phys_t pageno = pages / page_size;
-    if(pages < first_free)
-        first_free = pages;
-    for(size_t i=0; i<no_pages; i++, pages+=page_size) {
-        if(!isFree(pages))
-            continue;
-        phys_t index = pageno >> 5;
-        phys_t bit = pageno & 31;
-        pmm_bitmap[index] |= 1<<bit;
-        pageno++;
-    }
-}
-auto PMM::operator&&(phys_t page) -> bool {
-    phys_t pageno = page / page_size;
-    phys_t index = pageno >> 5;
-    if(!pmm_bitmap[index])
-        return false;
-    phys_t bit = pageno & 31;
-    if(!(pmm_bitmap[index] & (1<<bit)))
-        return false;
-    return true;
-}
-auto PMM::setUsed(phys_t page) -> void {
-    phys_t pageno = page / page_size;
-    phys_t index = pageno >> 5;
-    phys_t bit = pageno & 31;
-    pmm_bitmap[index] &= ~(1<<bit);
-}
-auto operator&&(phys_t a, PMM mm) -> bool {
-    return mm && a;
-}
+#ifdef BITS == 64
+#include "pmm64.hpp"
+#else
+#include "pmm32.hpp"
+#endif

kernel/src/pmm32.hpp

@@ -0,0 +1,131 @@
+#include <base.hpp>
+#include <pmm.hpp>
+extern "C" int kernel_start;
+extern "C" int kernel_end;
+
+
+uint32_t pmm_bitmap[32768];
+
+
+auto PMM::isFree(phys_t addr) -> bool {
+    if(addr == 0)
+        return false;
+    phys_t start = (phys_t)(&kernel_start);
+    phys_t end = (phys_t)(&kernel_end);
+    if((addr >= start) && (addr < end))
+        return false;
+    return true;
+}
+PMM::PMM(phys_t page_size): page_size(page_size), first_free(0), lowest_page(~0), highest_page(0) {
+    for(int i=0;i<32768;i++) {
+        pmm_bitmap[i]=0;
+    }
+    pmm = this;
+}
+void PMM::fill() {
+    for(phys_t i=highest_page; i>=lowest_page && i; i-=page_size) {
+        if(isFree(i))
+            *this << i;
+    }
+}
+PMM::~PMM() {}
+
+auto PMM::operator<<(phys_t page) -> PMM & {
+    (*this)(page,1);
+    return *this;
+}
+auto PMM::operator>>(phys_t &page) -> PMM & {
+    page = (*this, 1);
+    return *this;
+}
+
+auto PMM::operator,(size_t no_pages) -> phys_t {
+    if(first_free > highest_page)
+        panic("No free physical memory is available.");
+    if(no_pages == 1) {
+        while(!(first_free in *this)) {
+            first_free += page_size;
+            if(first_free > highest_page)
+                panic("No free physical memory is available.");
+        }
+        phys_t pageno = first_free / page_size;
+        phys_t index = pageno >> 5;
+        phys_t bit = pageno & 31;
+        pmm_bitmap[index] &= ~(1<<bit);
+        auto x = first_free;
+        first_free += page_size;
+        return x;
+    }
+    //Now we need to find a free page with n-1 free pages after it
+    phys_t linear_start = first_free;
+    phys_t length = (no_pages-1) * page_size;
+    while(true) {
+        bool found=true;
+        while(!(linear_start in *this)) {
+            linear_start += page_size;
+            if((linear_start > highest_page)||(linear_start+length > highest_page))
+                panic("No free physical memory is available.");
+        }
+        if(!((linear_start + length) in *this)) {
+            linear_start += no_pages * page_size;
+        }
+        //We're on to something
+        phys_t i;
+        for(i=linear_start; i < linear_start + length; i+=page_size) {
+            if(!(i in *this)) {
+                found=false;
+                break;
+            }
+        }
+        if(!found) {
+            linear_start=i+page_size;
+            continue;
+        }
+        //Set the first_free variable correctly when the first page was a hit
+        if(linear_start == first_free)
+            first_free += length + page_size;
+
+        phys_t pageno = linear_start / page_size;
+
+        for(i=linear_start; i <= linear_start + length; i+= page_size) {
+            phys_t index = pageno >> 5;
+            phys_t bit = pageno & 31;
+            pmm_bitmap[index] &= ~(1<<bit);
+            pageno++;
+        }
+        return linear_start;
+    }
+
+}
+auto PMM::operator()(phys_t pages, size_t no_pages) -> void {
+    phys_t pageno = pages / page_size;
+    if(pages < first_free)
+        first_free = pages;
+    for(size_t i=0; i<no_pages; i++, pages+=page_size) {
+        if(!isFree(pages))
+            continue;
+        phys_t index = pageno >> 5;
+        phys_t bit = pageno & 31;
+        pmm_bitmap[index] |= 1<<bit;
+        pageno++;
+    }
+}
+auto PMM::operator&&(phys_t page) -> bool {
+    phys_t pageno = page / page_size;
+    phys_t index = pageno >> 5;
+    if(!pmm_bitmap[index])
+        return false;
+    phys_t bit = pageno & 31;
+    if(!(pmm_bitmap[index] & (1<<bit)))
+        return false;
+    return true;
+}
+auto PMM::setUsed(phys_t page) -> void {
+    phys_t pageno = page / page_size;
+    phys_t index = pageno >> 5;
+    phys_t bit = pageno & 31;
+    pmm_bitmap[index] &= ~(1<<bit);
+}
+auto operator&&(phys_t a, PMM mm) -> bool {
+    return mm && a;
+}

kernel/src/pmm64.hpp

@@ -0,0 +1,143 @@
+#include <pmm.hpp>
+#include <paging.hpp>
+extern "C" int kernel_start;
+extern "C" int kernel_end;
+
+static inline void * map(phys_t addr) {
+    if(__builtin_expect(context_enabled, true))
+        return current_context->mmap(addr, (void*)1, protection::RW, false);
+    return (void*)addr;
+}
+static inline void unmap(void* addr) {
+/*    if(__builtin_expect(context_enabled, true))
+        current_context->munmap(addr);*/
+}
+
+auto PMM::isFree(phys_t addr) -> bool {
+    if(!addr)
+        return false;
+    auto start = (phys_t)(&kernel_start);
+    auto end = (phys_t)(&kernel_end);
+    if((addr >= start) && (addr < end))
+        return false;
+    return true;
+}
+
+void PMM::push(phys_t p) {
+    phys_t h=head;
+    auto ent=(pmm_entry*)map(p);
+    ent->next=head;
+    ent->last=0;
+    head=p;
+    unmap(ent);
+    ent=(pmm_entry*)map(h);
+    ent->last=p;
+    unmap(ent);
+}
+phys_t PMM::pop() {
+    phys_t p = head;
+    if(!p)
+        panic("oom");
+    auto ent=(pmm_entry*)map(p);
+    head=ent->next;
+    unmap(ent);
+    ent=(pmm_entry*)map(head);
+    ent->last=0;
+    unmap(ent);
+    return p;
+}
+
+PMM::PMM(phys_t page_size): page_size(page_size), head(0), lowest_page(~0), highest_page(0) {
+    pmm=this;
+}
+void PMM::fill() {
+    for(phys_t i=highest_page; i>=lowest_page && i; i-=page_size) {
+        if(isFree(i))
+            *this << i;
+    }
+}
+
+PMM::~PMM() {}
+
+auto PMM::operator<<(phys_t page) -> PMM & {
+    push(page);
+    return *this;
+}
+auto PMM::operator>>(phys_t &page) -> PMM& {
+    page=pop();
+    return *this;
+}
+#define self (*this)
+auto PMM::operator,(size_t no_pages) -> phys_t {
+    if(no_pages == 1)
+        return pop();
+    for(phys_t i = lowest_page; i < highest_page; i+=page_size) {
+        if(not (i in self))
+            continue;
+        if(not ((i+no_pages*page_size) in self)) {
+            i+=(no_pages-1)*page_size;
+            continue;
+        }
+        //we found something
+        for(phys_t j = i+page_size; j<i+no_pages*page_size; j+=page_size) {
+            if(not (j in self)) {
+                i+=(no_pages-1)*page_size;
+                goto outlbl;
+            }
+        }
+        //if we are here, we found it
+        for(phys_t j = i; j<=i+no_pages*page_size; j+=page_size) {
+            setUsed(j);
+        }
+        return i;
+outlbl:
+        continue;
+    }
+}
+
+auto PMM::operator()(phys_t pages, size_t no_pages) -> void {
+    for(phys_t i=pages; i<=pages+no_pages*page_size; i+=page_size) {
+        if(!isFree(i))
+            continue;
+        push(i);
+    }
+}
+
+auto PMM::operator&&(phys_t page) -> bool {
+    phys_t curr = head;
+    while(curr) {
+        if(curr == page)
+            return true;
+        auto ent = (pmm_entry *)map(curr);
+        curr = ent->next;
+        unmap(ent);
+    }
+    return false;
+}
+
+auto PMM::setUsed(phys_t page) -> void {
+    if(head == page) {
+        pop();
+        return;
+    }
+    if(not (page in self))
+        return;
+    phys_t next, last;
+    auto ent = (pmm_entry*)map(page);
+    next=ent->next;
+    last=ent->last;
+    unmap(ent);
+    if(next) {
+        ent=(pmm_entry*)map(next);
+        ent->last=last;
+        unmap(ent);
+    }
+    if(last) {
+        ent=(pmm_entry*)map(last);
+        ent->next=next;
+    }
+}
+
+auto operator&&(phys_t a, PMM mm) -> bool{
+    return mm in a;
+}