From 5b7bb880086de55070cb6d57246d5a262121eaa9 Mon Sep 17 00:00:00 2001
From: Bahadir Balban <bbalban@b-labs.co.uk>
Date: Thu, 28 Feb 2008 00:40:43 +0000
Subject: [PATCH] Wrote the bits that would fill in arg/env info to first page
 of task stack.

---
 tasks/mm0/include/task.h |  2 +-
 tasks/mm0/src/fault.c    | 17 ++++++++++++++++-
 tasks/mm0/src/task.c     |  6 +++---
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/tasks/mm0/include/task.h b/tasks/mm0/include/task.h
index 04cd7f6..87de34a 100644
--- a/tasks/mm0/include/task.h
+++ b/tasks/mm0/include/task.h
@@ -60,7 +60,7 @@ struct tcb {
 	unsigned long args_end;
 
 	/* UTCB address */
-	unsigned long utcb_addr;
+	unsigned long utcb_address;
 
 	/* Virtual memory areas */
 	struct list_head vm_area_list;
diff --git a/tasks/mm0/src/fault.c b/tasks/mm0/src/fault.c
index d0c038b..122551a 100644
--- a/tasks/mm0/src/fault.c
+++ b/tasks/mm0/src/fault.c
@@ -258,6 +258,20 @@ int is_env_arg_page(struct fault_data *fault)
 	return fault->address >= page_align(fault->task->stack_end);
 }
 
+int fill_env_arg_info(struct fault_data *fault, void *vaddr)
+{
+	/* Get the env start offset in the page */
+	unsigned long env_offset = fault->task->env_start & PAGE_MASK;
+
+	/* Write the environment information */
+	*(unsigned long *)(vaddr + env_offset) = fault->task->utcb_address;
+	printf("%s: Written env value 0x%x, to task address 0x%x\n",
+	       __TASKNAME__, fault->task->utcb_address,
+	       page_align(fault->address) + env_offset);
+
+	return 0;
+}
+
 /*
  * Handles any page allocation or file ownership change for anonymous pages.
  * For read accesses initialises a wired-in zero page and for write accesses
@@ -319,8 +333,9 @@ int do_anon_page(struct fault_data *fault)
 		/* Clear the page */
 		memset((void *)vaddr, 0, PAGE_SIZE);
 
+		/* If its the env/arg page on stack, fill that information */
 		if (is_env_arg_page(fault))
-			/* TODO: Fill in environment information here. */
+			fill_env_arg_info(fault, vaddr);
 
 		/* Remove temporary mapping */
 		l4_unmap((void *)vaddr, 1, self_tid());
diff --git a/tasks/mm0/src/task.c b/tasks/mm0/src/task.c
index ea57b94..8256f04 100644
--- a/tasks/mm0/src/task.c
+++ b/tasks/mm0/src/task.c
@@ -72,7 +72,7 @@ struct tcb *create_init_tcb(struct tcb_head *tcbs)
 	tcbs->total++;
 
 	/* Allocate a utcb virtual address */
-	task->utcb_addr = (unsigned long)utcb_vaddr_new();
+	task->utcb_address = (unsigned long)utcb_vaddr_new();
 
 	return task;
 }
@@ -158,8 +158,8 @@ int start_boot_tasks(struct initdata *initdata, struct tcb_head *tcbs)
 
 		/* mmap each task's utcb as single page anonymous memory. */
 		printf("%s: Mapping utcb for new task at: 0x%x\n", __TASKNAME__,
-		       task->utcb_addr);
-		if ((err = do_mmap(0, 0, task, task->utcb_addr,
+		       task->utcb_address);
+		if ((err = do_mmap(0, 0, task, task->utcb_address,
 				   VM_READ | VM_WRITE | VMA_ANON, 1) < 0)) {
 			printf("do_mmap: Mapping utcb failed with %d.\n", err);
 			goto error;