struggling with paging ...

1 files changed, 111 insertions, 18 deletions

diff --git a/kernel/vmem.c b/kernel/vmem.c
index f9d6050..3d62e97 100644
--- a/kernel/vmem.c
+++ b/kernel/vmem.c
@@ -83,6 +83,13 @@ typedef struct pdirectory_struct {
     pd_entry m_entries[PAGES_PER_DIR];
 }pdirectory;
 
+#define MAX_PAGEDIRS 10
+pdirectory *page_dirs[MAX_PAGEDIRS];
+int last_page_dir=0;
+int current_dir=0;
+
+////
+
 void pt_entry_add_attrib (pt_entry* e, uint32_t attrib)
 {
     *e|=attrib;
@@ -98,6 +105,13 @@ void pt_entry_set_frame (pt_entry* e , physical_addr addr)
     *e|=I86_PTE_FRAME&addr;
 
 }
+physical_addr pt_entry_get_frame (pt_entry* e)
+{
+     //          *e = (*e & ~I86_PTE_FRAME) | addr;                               
+
+    return *e&I86_PTE_FRAME;
+
+}
 bool pt_entry_is_present (pt_entry e)
 {
     return e&I86_PTE_PRESENT;
@@ -158,6 +172,7 @@ void		pd_entry_enable_global (pd_entry e)
 }
 */
 
+
 uint8_t vmmngr_alloc_page (pt_entry* e) 
 {
  
@@ -208,6 +223,30 @@ void show_cr()
 
 }
 
+uint32_t vmem_alloc_block_at(uint32_t virt_addr)
+{
+
+    uint32_t phys_addr=pmmngr_alloc_block();   // get free space from the memory manager
+    if (!phys_addr)panic(FOOLOS_MODULE_NAME,"unable to alloc spce");
+    pdirectory*	dir = page_dirs[current_dir];
+    pd_entry* entry = &dir->m_entries [PAGE_DIRECTORY_INDEX (virt_addr) ];
+    if(entry==0)panic(FOOLOS_MODULE_NAME,"no table present at requested addr :(");
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"found entry at %08X",entry);
+
+    //! 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_set_frame (&page, phys_addr);
+
+    //! ...and add it to the page table
+    ptable *table=pt_entry_get_frame(entry);
+    table->m_entries [PAGE_TABLE_INDEX (virt_addr) ] = page;
+    return phys_addr;
+
+}
+
+
 void vmem_init()
 {
     //log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"init paging (vesa base: 0x%08x)",vesa_physbase);
@@ -227,7 +266,6 @@ void vmem_init()
     {
 
 	ptable* table = (ptable*) pmmngr_alloc_block ();
-
 	if (!table)panic(FOOLOS_MODULE_NAME,"unable to alloc table");
 //	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"table: 0x%X",table);
     
@@ -256,10 +294,7 @@ void vmem_init()
 
     }
 
-    // programm space starts at 0x8048000 and let us reserve 4mb per programm!
-    // lets start to build the directory for one single programm
-//    uint32_t phys_addr=0;
-
+    // programm space (for init)
     virt_addr=0x8048000;
     for(int j=0;j<5;j++)
     {
@@ -269,12 +304,11 @@ void vmem_init()
     
 	for (int i=0, virt=virt_addr; i<1024; i++, virt+=4096) 
 	{
-	    phys_addr=pmmngr_alloc_block(); // get free space from the memory manager
+	    phys_addr=pmmngr_alloc_block();   // get free space from the memory manager
 	    if (!phys_addr)panic(FOOLOS_MODULE_NAME,"unable to alloc spce for frame");
 
 	    int frame=phys_addr;
 
-
 	    //! create a new page
 	    pt_entry page=0;
 	    pt_entry_add_attrib (&page, I86_PTE_PRESENT);
@@ -295,28 +329,87 @@ void vmem_init()
 
     }
 
-    x86_set_pdbr(dir);
+    page_dirs[last_page_dir++]=dir;
+    
 
+    x86_set_pdbr(dir);
     log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"enabling paging...");
-
-    show_cr();
-    
     x86_paging_enable();
 
-    //vesa_set_physbase(vesa_mapped);
-
-    show_cr();
-
 }
 
-void set_vmem1()
+void vmem_set_dir(int dir)
 {
-
+    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"set pagedir to %d",dir);
+    x86_set_pdbr(page_dirs[dir]);
+    current_dir=dir;
 }
 
-void set_vmem2()
+
+int vmem_new_space_dir()
 {
+    uint32_t vaddr=vmem_alloc_block_at(0xF0000000);
+    return 0;
+    pdirectory*	dir = vaddr;
+    if (!dir)panic(FOOLOS_MODULE_NAME,"unable to alloc pdirectory");
+
+    for(int i=0;i<1024;i++)dir->m_entries [i]=0;
 
+    // first clone the kernel space!
+    for(int i=0;i<3;i++)
+    {
+	dir->m_entries[i]=page_dirs[0]->m_entries[i];
+
+
+    }
+    return 0;
+    
+    // programm space starts at 0x8048000 and let us reserve 4mb per programm!
+    // lets start to build the directory for one single programm
+    // uint32_t phys_addr=0;
+    /*
+    uint32_t virt_addr=0x8048000;
+    uint32_t phys_addr;
+    for(int j=0;j<5;j++)
+    {
+
+	ptable* table = (ptable*) pmmngr_alloc_block ();
+	if (!table)panic(FOOLOS_MODULE_NAME,"unable to alloc table");
+    
+	for (int i=0, virt=virt_addr; i<1024; i++, virt+=4096) 
+	{
+	    phys_addr=pmmngr_alloc_block();   // get free space from the memory manager
+	    memcpy(phys_addr,virt_addr,4096); // duplicate current contents of this space!
+					    //
+	    if (!phys_addr)panic(FOOLOS_MODULE_NAME,"unable to alloc spce for frame");
+
+	    int 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_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);
+	pd_entry_set_frame (entry, (physical_addr)table);
+
+	virt_addr+=1024*4096;
+
+    }
+    */
+    page_dirs[last_page_dir]=dir;
+    return last_page_dir++;
 }
 
 
+
+