From 11c01ab7f67092354f2760fa60d34932442e8958 Mon Sep 17 00:00:00 2001
From: Eggert Jung <eggert.s.jung@wischhof13.de>
Date: Sat, 28 Feb 2026 23:15:41 +0100
Subject: [PATCH] rewrite ipc to use vaddress instead of paddr

---
 kernel/memory/pagetable.cc |  2 +-
 kernel/syscall/skeleton.cc | 53 +++++++++++++++++++++++++---------------------
 user/app1/appl.cc          | 32 ++++++++++++++--------------
 3 files changed, 46 insertions(+), 41 deletions(-)

diff --git a/kernel/memory/pagetable.cc b/kernel/memory/pagetable.cc
index d215551..578b319 100644
--- a/kernel/memory/pagetable.cc
+++ b/kernel/memory/pagetable.cc
@@ -188,7 +188,7 @@ void* getFreeVirtSpace(pagetable_t* l4, uint8_t num_pages){
             }
         }
         if(space_is_free){
-            //next_start_v = v+num_pages;
+            next_start_v = v+num_pages;
             return  (void*) ((uintptr_t) (v <<12));
         }
     }
diff --git a/kernel/syscall/skeleton.cc b/kernel/syscall/skeleton.cc
index 8385abd..d8708ac 100644
--- a/kernel/syscall/skeleton.cc
+++ b/kernel/syscall/skeleton.cc
@@ -132,9 +132,8 @@ namespace Syscall {
     }
 
     void exit(Vault &vault) {
-
-      unmap(vault, (void*) 0x4000, 512 );
       vault.scheduler.exit();
+      unmap(vault, (void*) 0x4000000, 512 );
     }
 
     void kill(Vault &vault, size_t pid){
@@ -175,24 +174,27 @@ namespace Syscall {
     }
 
 
-bool copy_from_phys(Vault& vault, uintptr_t phys_ptr, void* virt_ptr, size_t size) {
-	size_t offset = Page::offset(phys_ptr); 
+bool copy_from_phys(Vault& vault, uintptr_t src_paddr, void* dest_vaddr, size_t size) {
+	size_t offset = Page::offset(src_paddr);
 	size_t total_size = size + offset;
     four_lvl_paging_t* search_table = vault.scheduler.active()->paging_tree;
 
-	void* virt_addr =  getFreeVirtSpace(search_table->l4, (total_size/4096)+1); // page aligned pointer 
-	if (virt_addr == nullptr) {
+	uintptr_t src_vaddr = (uintptr_t)getFreeVirtSpace(search_table->l4, (total_size/4096)+1); // page aligned pointer
+	if (src_vaddr == 0) {
 		return false;
 	}
+    src_vaddr += offset;
 
     for(uint8_t i =0; i<size/4096  +1; i++){
-        //TODO actually use loop
-        setMapping((uintptr_t)virt_addr, (void*)phys_ptr, vault.scheduler.active()->paging_tree->l4);
+        setMapping(src_vaddr+(uintptr_t)(i*4096), (void*)(src_paddr+(uintptr_t)(i*4096)), search_table->l4);
+    }
+
+	memcpy(dest_vaddr, (void*)src_vaddr, size);
+
+    for(uint8_t i =0; i<size/4096  +1; i++){
+        setMapping((uintptr_t)(src_vaddr), 0, search_table->l4);
     }
 
-	memcpy(virt_ptr, (void*)((uintptr_t)(virt_addr)+ (uintptr_t)offset), size);
-    setMapping((uintptr_t)(virt_addr), 0, search_table->l4);
-	
 	return true;
 }
 
@@ -202,16 +204,15 @@ bool send(Vault& v, int pid, const void* sbuffer, size_t ssize, void* rbuffer, s
 	Thread* current_thread = v.scheduler.active();
 	Thread* target_thread = v.thread_list[pid];
 
-	uintptr_t sbuffer_ptr = isMapped((uintptr_t)sbuffer,v.scheduler.active()->paging_tree->l4) + ((uintptr_t)sbuffer&0xFFF);
-IpcStruct msg {
-  .ptr        = sbuffer_ptr,
-  .size       = ssize,
-  .pid        = current_thread->id,
-  .is_answer  = false,
-  .queue_link = nullptr
-};
-
+	//uintptr_t sbuffer_ptr = isMapped((uintptr_t)sbuffer,v.scheduler.active()->paging_tree->l4) + ((uintptr_t)sbuffer&0xFFF);
 
+    IpcStruct msg = {
+        .ptr        = (uintptr_t)sbuffer,
+        .size       = ssize,
+        .pid        = current_thread->id,
+        .is_answer  = false,
+        .queue_link = nullptr
+    };
 
 	target_thread->ipc_queue.enqueue(msg);
 	target_thread->ipc_sem.v(v);
@@ -239,7 +240,7 @@ int receive(Vault& v, void* buffer, size_t size) {
 
 	// Warte auf Nachricht
 	//if (thread->ipc_queue.is_empty()) {
-		thread->ipc_sem.p(v);
+    thread->ipc_sem.p(v);
 	//}
 	
 	IpcStruct* ipc = thread->ipc_queue.first();
@@ -247,9 +248,13 @@ int receive(Vault& v, void* buffer, size_t size) {
 	
     size_t copy_len = (size < ipc->size) ? size:ipc->size;
 	// Buffer holen
-	if (!copy_from_phys(v, ipc->ptr, buffer, copy_len)) {
-		return -3;
-	}
+    
+    for(uint32_t i=0; i<(copy_len/4096)+1; i++){
+        uintptr_t paddr = isMapped((ipc->ptr)+(i*4096), v.thread_list[ipc->pid]->paging_tree->l4);
+        if (!copy_from_phys(v, paddr, buffer, copy_len)) {
+            return -3;
+        }
+    }
 	
 	return ipc->pid;
 }
diff --git a/user/app1/appl.cc b/user/app1/appl.cc
index d2f8d28..139e207 100644
--- a/user/app1/appl.cc
+++ b/user/app1/appl.cc
@@ -6,25 +6,25 @@ char sbuf[8194], rbuf[8194]; // (2 * 4KiB) + 2
 void main() {
     fork();
     fork();
+    int other = fork();
     int ppid = sys_getpid();
     write(1, "app", 3, 0, ppid);
-    int other = fork();
-    if (ppid == other) { // child
-        sbuf[0] = 3;
-        sbuf[8192] = sys_getpid();
-        sbuf[8193] = 1;
-        send(other, sbuf, 8193, rbuf, 8193);
+    //if (ppid == other) { // child
+    //    sbuf[0] = 3;
+    //    sbuf[8192] = sys_getpid();
+    //    sbuf[8193] = 1;
+    //    send(other, sbuf, 8193, rbuf, 8193);
  
-        char msg[] = "REPLY: AA\n";
-        msg[7] += rbuf[0] + sbuf[8193];
-        msg[8] += 4 + ppid;
-        write(0, msg, 10);
-    } else { // parent
-        receive(rbuf, 8193);
-        rbuf[0] = rbuf[0] + rbuf[8192];
-        rbuf[8193] = 7;
-        reply(rbuf, 8193);
-    }
+    //    char msg[] = "REPLY: AA\n";
+    //    msg[7] += rbuf[0] + sbuf[8193];
+    //    msg[8] += 4 + ppid;
+    //    write(0, msg, 10);
+    //} else { // parent
+    //    receive(rbuf, 8193);
+    //    rbuf[0] = rbuf[0] + rbuf[8192];
+    //    rbuf[8193] = 7;
+    //    reply(rbuf, 8193);
+    //}
  
     sys_exit();
 }