From 9ad0eafcf7e2f3e0532666c5353b0f5294401b06 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Tue, 20 Jul 2021 21:38:09 +0200
Subject: per-process virtual memory
VGA is only mapped into the virtual memory because there are no other
ways of interacting with the OS.
---
src/kernel/proc.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
(limited to 'src/kernel/proc.c')
diff --git a/src/kernel/proc.c b/src/kernel/proc.c
index 4a931a5..6b80254 100644
--- a/src/kernel/proc.c
+++ b/src/kernel/proc.c
@@ -1,19 +1,30 @@
#include <kernel/arch/generic.h>
#include <kernel/mem.h>
#include <kernel/proc.h>
+#include <stdint.h>
struct process *process_current;
-struct process *process_new(void *eip) {
- struct process *proc;
- proc = page_alloc(1); // TODO kmalloc
- proc->stack_top = proc->esp = page_alloc(1) + 1 * PAGE_SIZE;
- proc->eip = eip;
+struct process *process_new() {
+ struct process *proc = page_alloc(1); // TODO kmalloc
+ proc->pages = pagedir_new();
+ // map the stack to the last page in memory
+ pagedir_map(proc->pages, (void*)~PAGE_MASK, page_alloc(1), true, true);
+ proc->stack_top = proc->esp = (void*) ~0;
+
+ // map the kernel
+ // yup, .text is writeable too. the plan is to not map the kernel
+ // into user memory at all, but i'll implement that later. TODO
+ for (size_t p = 0x100000; p < &_bss_end; p += PAGE_SIZE)
+ pagedir_map(proc->pages, (void*)p, (void*)p, false, true);
+
+ // the kernel still has to load the executable code and set EIP
return proc;
}
void process_switch(struct process *proc) {
process_current = proc;
+ pagedir_switch(proc->pages);
sysexit(proc->eip, proc->esp);
}
--
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