From f30c9803f05e90087e367953aa142275f8688f61 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Sun, 26 Apr 2020 23:23:42 +0200
Subject: Awesome new multitasking system and scheduler

---
 src/kernel/tasks/userspace.c | 65 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 src/kernel/tasks/userspace.c

(limited to 'src/kernel/tasks/userspace.c')

diff --git a/src/kernel/tasks/userspace.c b/src/kernel/tasks/userspace.c
new file mode 100644
index 0000000..f8d0472
--- /dev/null
+++ b/src/kernel/tasks/userspace.c
@@ -0,0 +1,65 @@
+#include <stdint.h>
+#include <stddef.h>
+#include <kernel/system.h>
+#include <kernel/tasks/userspace.h>
+#include <kernel/tasks/process.h>
+#include <kernel/memory/paging.h>
+#include <kernel/io/io.h>
+#include <kernel/interrupts/interrupts.h>
+#include <kernel/lib/lib.h>
+
+struct process *proc_bottom = NULL;
+
+uint32_t hl_cr3;
+uint32_t hl_eip;
+uint32_t hl_esp;
+
+uint32_t spawn_child(struct process *child)
+{
+	return (uint32_t)-1;
+}
+
+void userspace_enter(struct process *proc)
+{
+	proc_bottom = proc;
+	proc->next = NULL;
+	hl_eip = proc->registers.eip;
+	hl_esp = proc->registers.esp;
+	paging_switch_directory(proc->cr3);
+
+	current_proc = proc;
+
+	sti();
+	jump_userspace();
+}
+
+void single_yield(struct process *proc, struct regs *regs)
+{
+	memcpy(&proc_bottom->registers, regs, sizeof(struct regs));
+
+	if (proc == proc_bottom)
+		panic("Can't return from parent process");
+
+	proc->next = proc_bottom;
+	proc_bottom = proc;
+
+	memcpy(regs, &proc->registers, sizeof(struct regs));
+	paging_switch_directory(proc->cr3);
+}
+
+uint32_t single_exit(struct regs *regs)
+{
+	//close(current_proc->stdout);
+	//close(current_proc->stderr);
+
+	uint32_t hold = regs->ebx;
+	proc_bottom = proc_bottom->next;
+
+	if (proc_bottom == NULL)
+		panic("Return from process with no parent");
+
+	memcpy(regs, &proc_bottom->registers, sizeof(struct regs));
+	paging_switch_directory(proc_bottom->cr3);
+
+	return hold;
+}
\ No newline at end of file
-- 
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