fixing paging / per cpu pages

1 files changed, 109 insertions, 17 deletions

diff --git a/kernel/vmem.c b/kernel/vmem.c
index ff464ea..04f0354 100644
--- a/kernel/vmem.c
+++ b/kernel/vmem.c
@@ -40,6 +40,7 @@ typedef struct ptable_struct {
 typedef struct pdirectory_struct {
     pd_entry m_entries[PAGES_PER_DIR];
 }pdirectory;
+
 static uint32_t kernel_pages;
 uint32_t fb_addr; // TODO!??!!? how can we share so ugly with vesa
 static uint32_t apic_addr;
@@ -197,7 +198,7 @@ static pt_entry* vmmngr_ptable_lookup_entry (ptable* p, virtual_addr addr)
 /// SHIT BELOW THIs LINE
 void vmem_free_dir(pdirectory *dir)
 {
-    x86_paging_disable();
+    x86_paging_disable(); //TODO : do not disable this!
 
     uint32_t virt_addr=0;
 
@@ -250,7 +251,110 @@ void vmem_free_dir(pdirectory *dir)
     x86_paging_enable();
 }
 
+static pdirectory*  vmem_clean_dir()
+{
+    fixme("replace ALLL kballoc with getting the pages from mem/vmem");
+    pdirectory* dir = (pdirectory*) kballoc(1);
+    for(int i=0;i<1024;i++)dir->m_entries [i]=0; // zero all
+    klog("fresh page directory: 0x%X",dir);
+    return dir;
+}
+
+static void vmem_add_alloc(pdirectory* dir,uint32_t start,uint32_t pages)
+{
+    uint32_t virt_addr=start;
+    for(int j=0;j<2;j++)
+    {
+
+	ptable* table = (ptable*) kballoc (1);
+	pd_entry *oldentry=NULL;
+	ptable* oldtable=NULL;
+    
+	for (int i=0, virt=virt_addr; i<1024; i++, virt+=4096) 
+	{
+	    //klog("i = %d",i);
+	    uint32_t phys_addr=mem_alloc_block();   // get free space from the memory manager
+
+	    uint32_t frame=phys_addr;
+
+	    //! create a new page
+	    pt_entry page=0;
+	    pt_entry_add_attrib (&page, I86_PTE_PRESENT);
+	    pt_entry_add_attrib (&page, I86_PTE_WRITABLE);
+	    pt_entry_add_attrib (&page, I86_PTE_USER);
+	    pt_entry_set_frame (&page, frame);
+
+	    //! ...and add it to the page table
+	    table->m_entries [PAGE_TABLE_INDEX (virt) ] = page;
+	}
+	
+	pd_entry* entry = &dir->m_entries [PAGE_DIRECTORY_INDEX (virt_addr) ];
+	*entry=0;
+	pd_entry_add_attrib (entry, I86_PDE_PRESENT);
+	pd_entry_add_attrib (entry, I86_PDE_WRITABLE);
+	    pt_entry_add_attrib (entry, I86_PTE_USER);
+	pd_entry_set_frame (entry, (physical_addr)table);
+
+	virt_addr+=1024*4096;
+    }
+
+}
+
+static void vmem_add_identity(pdirectory* dir,uint32_t start,uint32_t pages)
+{
+    fixme("make sure the pages are marked as used in the physical mem manager");
+
+    uint32_t phys_addr=start;
+    uint32_t virt_addr=start;
+
+    while(pages>0)
+    {
+	//  each table in our page directory maps 1024*4096 bytes
+	ptable* table;
+	table = (ptable*) kballoc(1);
+        for(int i=0;i<1024;i++)table->m_entries [i]=0; // zero all
+
+	//! idenitity mapping
+	for (int i=0, frame=phys_addr, virt=virt_addr; i<1024; i++, frame+=4096, virt+=4096) 
+	{
+	    //! create a new page
+	    pt_entry page=0;
+	    pt_entry_add_attrib (&page, I86_PTE_PRESENT);
+	    pt_entry_add_attrib (&page, I86_PTE_WRITABLE);
+	    pt_entry_add_attrib (&page, I86_PTE_USER);
+	    pt_entry_set_frame (&page, frame);
+
+	    //! ...and add it to the page table
+	    table->m_entries [PAGE_TABLE_INDEX (virt) ] = page;
+	    pages--;
+	    if(pages<=0)break;
+	}
+
+	pd_entry* entry = &dir->m_entries [PAGE_DIRECTORY_INDEX (virt_addr) ];
+	*entry=0;
+	pd_entry_add_attrib (entry, I86_PDE_PRESENT);
+	pd_entry_add_attrib (entry, I86_PDE_WRITABLE);
+	pd_entry_add_attrib (entry, I86_PDE_USER);
+	pd_entry_set_frame (entry, (physical_addr)table);
+
+	phys_addr+=1024*4096;
+	virt_addr+=1024*4096;
+    }
+}
 
+pdirectory* vmem_kernel_dir()
+{
+    fixme("remove user flags where appropriate");
+    fixme("do not waste soo many pages/page tables!");
+    fixme("align properly!! / merge page tables if required!");
+    pdirectory* dir = vmem_clean_dir();
+    vmem_add_identity(dir,0,1024*8);//first 32 megs 
+    if(fb_addr>0x100000)vmem_add_identity(dir,fb_addr,1024*4);//16megs (?) TODO: dynamic
+    vmem_add_identity(dir,apic_addr,1024*2); 
+    vmem_add_identity(dir,io_apic_addr,1024*2); 
+    vmem_add_alloc(dir,0x8000000,1024*4);
+    return dir;
+}
 
 //
 //  vmem init /  also copies all the shit over for FORK 
@@ -266,22 +370,14 @@ void vmem_free_dir(pdirectory *dir)
 
 pdirectory* vmem_new_space_dir(pdirectory *copy_dir,bool stack_only)
 {
-    x86_paging_disable();
-
-    //
-    pdirectory* dir = (pdirectory*) kballoc(1);
-
-    klog("new pdirectory: 0x%X",dir);
-    if (!dir)kpanic("unable to alloc pdirectory");
+    x86_paging_disable(); //TODO: do not disable
 
-    // first of all let's zero all the entries
-    for(int i=0;i<1024;i++)dir->m_entries [i]=0;
+    pdirectory* dir = vmem_clean_dir();
 
     // identity mapping for first blocks
     uint32_t phys_addr=0;
     uint32_t virt_addr=0;
-
-    kernel_pages=8;
+    kernel_pages=8; //32megs
 
     // first pages are identity mapped
     for(int j=0;j<kernel_pages;j++)
@@ -619,14 +715,10 @@ pdirectory* vmem_new_space_dir(pdirectory *copy_dir,bool stack_only)
     return dir;
 }
 
-pdirectory* vmem_init(uint32_t kernel_blocks, uint32_t frameb_addr, uint32_t apic_ad, uint32_t ioapic_ad)
+void vmem_init(uint32_t kernel_blocks, uint32_t frameb_addr, uint32_t apic_ad, uint32_t ioapic_ad)
 {
     fixme("do not share fb_addr with syscalls like that!");
     fb_addr=frameb_addr;
     apic_addr=apic_ad;
     io_apic_addr=ioapic_ad;
-    kernel_pages=kernel_blocks/1024+1;
-    return vmem_new_space_dir(NULL,false);
 }
-
-