1 files changed, 60 insertions, 31 deletions

diff --git a/kernel/vmem.c b/kernel/vmem.c
index 53e33c4..0a9e4b1 100644
--- a/kernel/vmem.c
+++ b/kernel/vmem.c
@@ -85,7 +85,7 @@ typedef struct pdirectory_struct {
 
 #define MAX_PAGEDIRS 10
 pdirectory *page_dirs[MAX_PAGEDIRS];
-int last_page_dir=0;
+int next_page_dir=0;
 int current_dir=0;
 
 ////
@@ -107,8 +107,6 @@ void pt_entry_set_frame (pt_entry* e , physical_addr addr)
 }
 physical_addr pt_entry_get_frame (pt_entry* e)
 {
-     //          *e = (*e & ~I86_PTE_FRAME) | addr;                               
-
     return *e&I86_PTE_FRAME;
 
 }
@@ -140,6 +138,12 @@ void		pd_entry_set_frame (pd_entry* e, physical_addr add)
 {
     *e|=I86_PDE_FRAME&add;
 }
+physical_addr pd_entry_get_frame (pd_entry* e)
+{
+    return *e&I86_PDE_FRAME;
+
+}
+
 bool		pd_entry_is_present (pd_entry e)
 {
     return e&I86_PDE_PRESENT;
@@ -249,7 +253,8 @@ uint32_t vmem_alloc_block_at(uint32_t virt_addr)
 }
 */
 
-int vmem_new_space_dir()
+// vmem init and also copies all the shit for FORK 
+volatile int vmem_new_space_dir()
 {
     x86_paging_disable();
     
@@ -266,41 +271,58 @@ int vmem_new_space_dir()
     for(int j=0;j<3;j++)
     {
 
-	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);
-    
+	// this is the table for our page directory. It maps 1024*4096 bytes
+	ptable* table;
 
-	//! idenitity mapping
-	for (int i=0, frame=phys_addr, virt=virt_addr; i<1024; i++, frame+=4096, virt+=4096) 
+	// create new tables on init
+	if(next_page_dir==0)
 	{
-	    //! 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);
+	    // alloc space for our new table
+	    table = (ptable*) pmmngr_alloc_block ();
+	    if (!table)panic(FOOLOS_MODULE_NAME,"unable to alloc table");
+
+	    //! 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_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);
+
+	}
+	// otherwise simply take existing stuff from pdir 0
+	else
+	{
+	    dir->m_entries[PAGE_DIRECTORY_INDEX(virt_addr)]=
+		page_dirs[0]->m_entries[PAGE_DIRECTORY_INDEX(virt_addr)];
 
-	    //! ...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);
 
 	phys_addr+=1024*4096;
 	virt_addr+=1024*4096;
-
     }
 
-    // programm space (for init)
+    // programm space 
     virt_addr=0x8048000;
     for(int j=0;j<2;j++)
     {
 
 	ptable* table = (ptable*) pmmngr_alloc_block ();
+	pd_entry *oldentry= &(page_dirs[0]->m_entries[PAGE_DIRECTORY_INDEX(virt_addr)]);
+	ptable* oldtable=pd_entry_get_frame(oldentry);
+	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"oldtable at: 0x%08X",oldtable);
+
 	if (!table)panic(FOOLOS_MODULE_NAME,"unable to alloc table");
 	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"alloc table: %08X",table);
     
@@ -309,6 +331,16 @@ int vmem_new_space_dir()
 	    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");
 
+	    // if this is not init , copy contents from current space!
+	    if(next_page_dir!=0)
+	    {
+		uint32_t addr_old=pt_entry_get_frame(&oldtable->m_entries[PAGE_TABLE_INDEX(virt)]);
+		log(FOOLOS_MODULE_NAME,FOOLOS_LOG_FINE,"physical memcpy(0x%08X,0x%08X,4096)",phys_addr, addr_old);
+		memcpy(phys_addr,addr_old,4096);
+
+	    }
+
+
 	    int frame=phys_addr;
 
 	    //! create a new page
@@ -331,19 +363,16 @@ int vmem_new_space_dir()
 
     }
 
-    page_dirs[last_page_dir]=dir;
-    if(last_page_dir!=0)x86_paging_enable();
-    return last_page_dir++;
+    page_dirs[next_page_dir]=dir;
+    if(next_page_dir!=0)x86_paging_enable();
+    return next_page_dir++;
 
 }
 
 void vmem_set_dir(int dir)
 {
-//    x86_paging_disable();
     x86_set_pdbr(page_dirs[dir]);
-   // log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"set pagedir to %d (0x%08X)",dir,page_dirs[dir]);
     current_dir=dir;
-//    x86_paging_enable();
 }