From: Matthias Kruk <m@m10k.eu>
Date: Thu, 19 Sep 2019 10:34:19 +0000 (+0900)
Subject: Keep a pointer to the kernel stack in struct task, instead of the entire stack
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=2afddfe26671d73db5dd6bbad766c378c349a93a;p=corax

Keep a pointer to the kernel stack in struct task, instead of the entire stack
---

diff --git a/kernel/arch/task.S b/kernel/arch/task.S
index 31d2f62..4cad113 100644
--- a/kernel/arch/task.S
+++ b/kernel/arch/task.S
@@ -49,12 +49,11 @@ task_prepare:
 
 	/* store cr3 in task structure */
 	movl	8(%esp), %eax
-	movl	%eax, 4(%edi)
+	movl	%eax, OFFSET_CR3(%edi)
 
 	/* calculate stack start (since it grows down) */
-	movl	$CONFIG_KERNEL_STACK_SIZE, %ecx
-	movl	(%esp), %eax
-	leal	OFFSET_KSTACK(%eax, %ecx, 1), %eax
+	movl	OFFSET_KSTACK(%edi), %eax
+	addl	$CONFIG_KERNEL_STACK_SIZE, %eax
 
 	/*
 	 * We will use _int_restore (the lower half of the interrupt handler)
@@ -130,9 +129,8 @@ task_prepare:
 	movl	(%eax), %ecx
 	movl	%ecx, 60(%eax)
 
-	/* put EAX into the task structure */
-	movl	4(%esp), %ecx
-	movl	%eax, OFFSET_ESP0(%ecx)
+	/* put EAX into the task structure - task pointer is still in EDI */
+	movl	%eax, OFFSET_ESP0(%edi)
 
 	/* that should be it */
 	ret
diff --git a/kernel/include/arch.h b/kernel/include/arch.h
index 06f1932..787cdf8 100644
--- a/kernel/include/arch.h
+++ b/kernel/include/arch.h
@@ -24,8 +24,7 @@
 struct task {
 	u32_t t_sp;
 	u32_t t_pgdir;
-
-	u8_t  t_kstack[CONFIG_KERNEL_STACK_SIZE];
+	void *t_kstack;
 } __attribute__((packed));
 
 int     cpu_get_id(void);