arch/x86/paging.h

@@ -17,6 +17,7 @@
 #define PAGING_MEM_USER (1U << 0)
 #define PAGING_MEM_READ (1U << 1)
 #define PAGING_MEM_WRITE (1U << 2)
+#define PAGING_MEM_EXEC (1U << 3)
 
 int pagingSetup(paddr_t lowerKernelAddr, paddr_t upperKernelAddr);
 

core/main.c

@@ -84,7 +84,7 @@ void loadUserSpace()
         return;
     }
 
-    struct process *proc = processCreate("UserSpace");
+    struct process *proc = processCreate("init");
 
     threadChangeCurrentContext(processGetMMUContext(proc));
     uaddr_t prog = loadElfProg(buf + FILE_HEADER_SIZE, proc);
@@ -101,7 +101,7 @@ void loadUserSpace()
                    PAGING_MEM_USER | PAGING_MEM_WRITE | PAGING_MEM_READ) == 0);
     unrefPhyPage(stackPhy);
 
-    threadCreateUser("UserProg", proc, prog, 0, 0, stackTop);
+    threadCreateUser("init", proc, prog, 0, 0, stackTop);
     processUnref(proc);
     threadChangeCurrentContext(NULL);
 

core/syscall.c

@@ -7,6 +7,8 @@
 #include "types.h"
 #include "uaccess.h"
 #include "uaddrspace.h"
+#include "zero.h"
+
 
 int syscallExecute(int syscallId, const struct cpu_state *userCtx)
 {
@@ -71,6 +73,9 @@ int syscallExecute(int syscallId, const struct cpu_state *userCtx)
                                   (unsigned int *)&flags, (unsigned int *)&userPath);
             strzcpyFromUser((vaddr_t *)path, (uaddr_t *)userPath, sizeof(path));
             printf("Trying mmap for device %s\n", path);
+            if(strcmp(path, "/dev/zero") == 0){
+                zeroMmap(as, &uaddr, size, rights,flags);
+            }
             (void)as;
             break;
         }

core/uaddrspace.c

@@ -14,18 +14,6 @@
 #include <stddef.h>
 #include <stdint.h>
 
-struct uAddrVirtualReg {
-    uaddr_t addr;
-    size_t size;
-    int right;       // PAGING_MEM_*
-    uint32_t offset; // in the mappedRessource
-    uint flags;
-
-    struct mappedRessource *res;
-    struct uAddrVirtualReg *nextInAddrSpace, *prevInAddrSpace;
-    struct uAddrVirtualReg *nextInMappedRes, *prevInMappedRes;
-};
-
 struct uAddrSpace {
     struct process *process; // The process that is represented by this AS
     struct mmu_context *ctx; // The corresponding MMU configuration
@@ -33,22 +21,9 @@ struct uAddrSpace {
     struct uAddrVirtualReg *listVirtualReg; // List of Virtual Region used by this process
 
     uaddr_t heapStart; // Start of the Head
-    size_t heapSize;   // Hep size -> modified by brk()
+    size_t heapSize;   // Heap size -> modified by brk()
 };
 
-struct mappedRessourceOps {
-    int (*open)(struct uAddrVirtualReg *vreg);
-    int (*close)(struct uAddrVirtualReg *vreg);
-    int (*unmap)(struct uAddrVirtualReg *vregi, uaddr_t addr, size_t size);
-    int (*nopage)(struct uAddrVirtualReg *vregi, uaddr_t addr,
-                  int right); // Called by the pageflt handler when the page is missing
-};
-
-struct mappedRessource {
-    int right; // PAGING_MEM_*
-    struct mappedRessourceOps *ops;
-    struct uAddrVirtualReg *listVirtualReg;
-};
 
 struct uAddrSpace *uAddrSpaceCreate(struct process *proc)
 {
@@ -161,3 +136,15 @@ free_ppage:
     unrefPhyPage(ppage);
     return -1;
 }
+
+int uAddrSpaceMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags,
+                   struct mappedRessource *res)
+{
+        (void)as;
+        (void)uaddr;
+        (void)rights;
+        (void)size;
+        (void)flags;
+        (void)res;
+    return 0;
+}

core/uaddrspace.h

@@ -7,9 +7,41 @@
 struct uAddrSpace;
 struct uAddrVirtualReg;
 
+// TODO : move this struct to .c and add accessors
+struct uAddrVirtualReg {
+    uaddr_t addr;
+    size_t size;
+    int right;       // PAGING_MEM_*
+    uint32_t offset; // in the mappedRessource
+    uint flags;
+
+    struct mappedRessource *res;
+    struct uAddrVirtualReg *nextInAddrSpace, *prevInAddrSpace;
+    struct uAddrVirtualReg *nextInMappedRes, *prevInMappedRes;
+};
+
+struct mappedRessourceOps {
+    int (*open)(struct uAddrVirtualReg *vreg);
+    int (*close)(struct uAddrVirtualReg *vreg);
+    int (*unmap)(struct uAddrVirtualReg *vreg, uaddr_t addr, size_t size);
+    int (*nopage)(struct uAddrVirtualReg *vreg, uaddr_t addr,
+                  int right); // Called by the pageflt handler when the page is missing
+};
+
+struct mappedRessource {
+    int allowedRight; // PAGING_MEM_*
+    struct mappedRessourceOps *ops;
+    struct uAddrVirtualReg *listVirtualReg;
+    void *customData;
+};
+
+
 struct uAddrSpace * uAddrSpaceCreate(struct process *proc);
 int uAddrSpaceDelete(struct uAddrSpace *addr);
 struct mmu_context * uAddrSpaceGetMMUContext(struct uAddrSpace *addr);
 int uAddrSpaceSetHeap(struct uAddrSpace *as, uaddr_t addr, size_t size);
 int uAddrSpaceCheckNAlloc(struct uAddrSpace *as, vaddr_t addr);
 uaddr_t sysBrk(struct uAddrSpace *as, uaddr_t newHeapTop);
+
+int uAddrSpaceMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags,
+                   struct mappedRessource *res);

drivers/zero.c

@@ -0,0 +1,45 @@
+#include "zero.h"
+#include "alloc.h"
+
+struct zeroMappedEntry {
+        int refCnt;
+};
+
+static int zeroOpen(struct uAddrVirtualReg *vreg)
+{
+        (void)vreg;
+        return 0;
+}
+static int zeroClose(struct uAddrVirtualReg *vreg)
+{
+        (void)vreg;
+        return 0;
+}
+static int zeroNoPage(struct uAddrVirtualReg *vreg, uaddr_t addr, int right)
+{
+        (void)vreg;
+        (void)addr;
+        (void)right;
+        return 0;
+}
+
+static struct mappedRessourceOps zeroOps = {
+    .open   = zeroOpen,
+    .close  = zeroClose,
+    .unmap  = NULL,
+    .nopage = zeroNoPage,
+};
+
+int zeroMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags)
+{
+        struct mappedRessource *res  = (struct mappedRessource *)zalloc(sizeof(struct mappedRessource));
+        struct zeroMappedEntry *cust = (struct zeroMappedEntry *)zalloc(sizeof(struct zeroMappedEntry));
+
+        res->allowedRight = PAGING_MEM_READ | PAGING_MEM_WRITE | PAGING_MEM_EXEC | PAGING_MEM_USER;
+        res->ops          = &zeroOps;
+        res->customData   = cust;
+
+        uAddrSpaceMmap(as, uaddr, size, rights, flags, res);
+
+        return 0;
+}

drivers/zero.h

@@ -2,8 +2,10 @@
 
 
 #include "types.h"
+#include "uaddrspace.h"
+
 #include <stddef.h>
 #include <stdint.h>
 int zeroSetup();
 
-int zeroMmap(uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags);
+int zeroMmap(struct uAddrSpace *as, uaddr_t *uaddr, size_t size, uint32_t rights, uint32_t flags);