From d41ffbbedc797f74658222e2084ee0506a32ae58 Mon Sep 17 00:00:00 2001
From: josh <josh@5b3e749e-e535-0410-8002-a9bb6afbdfca>
Date: Thu, 28 Jan 2010 04:22:02 +0000
Subject: [PATCH] added mm_early_vpage_alloc(); kernel still crashing...

git-svn-id: svn://anubis/hos/trunk@98 5b3e749e-e535-0410-8002-a9bb6afbdfca
---
 kernel/isr/interrupts.cc |  9 ++++++---
 kernel/mm/mm.cc          | 15 +++++++++++++++
 kernel/mm/mm.h           |  1 +
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/kernel/isr/interrupts.cc b/kernel/isr/interrupts.cc
index 6c301df..cbc82ac 100644
--- a/kernel/isr/interrupts.cc
+++ b/kernel/isr/interrupts.cc
@@ -49,8 +49,11 @@ void isr(u8_t int_num, int_stack_t * istack)
 
 void interrupts_bootstrap()
 {
-    u32_t idt_base = mm_page_alloc();
-    u64_t * idt = (u64_t *) (idt_base + KERNEL_OFFSET);
+    u32_t idt_phys = mm_page_alloc();
+    u32_t idt_virt = mm_early_vpage_alloc();
+    mm_map(idt_virt, idt_phys, 0, 1);
+
+    u64_t * idt = (u64_t *) idt_virt;
     idt[0]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_0,  0);
     idt[1]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_1,  0);
     idt[2]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_2,  0);
@@ -101,7 +104,7 @@ void interrupts_bootstrap()
     idt[47] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_47, 0);
     idt[48] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_48, 0);
     idt[49] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_49, 0);
-    idtr.base = idt_base;
+    idtr.base = idt_phys;
     idtr.limit = 49 * sizeof(idt[0]) - 1;
     __asm__ __volatile__ ("lidt (idtr)");
 }
diff --git a/kernel/mm/mm.cc b/kernel/mm/mm.cc
index 8f427f6..4ce5846 100644
--- a/kernel/mm/mm.cc
+++ b/kernel/mm/mm.cc
@@ -131,6 +131,8 @@ void mm_bootstrap()
     /* move the heap back to after the page allocation pages */
     mm_heap_base = (u32_t) &page_alloc_pages[last_page_alloc_page + 1];
 
+    /* ok, now mm_early_vpage_alloc() should be functional */
+
     /* allocate the page directory */
     u32_t page_directory_phys = mm_early_page_alloc();
     early_page_directory_ptr = (pagedirectory_t *)
@@ -359,6 +361,19 @@ u32_t mm_page_alloc()
     return page_address;
 }
 
+/**************************************************************************
+ * This function allocates a virtual page. It should only be called       *
+ * during the bootstrap process, before the kernel begins its normal      *
+ * operation. It adjusts the heap pointer to push it back beyond any      *
+ * bootstrap pages allocated.                                             *
+ *************************************************************************/
+u32_t mm_early_vpage_alloc()
+{
+    u32_t vaddress = mm_heap_base;
+    mm_heap_base += PAGE_SIZE;
+    return vaddress;
+}
+
 void mm_print_memory_map()
 {
     kprintf("Bootloader provided memory map:\n");
diff --git a/kernel/mm/mm.h b/kernel/mm/mm.h
index 634e443..fea5997 100644
--- a/kernel/mm/mm.h
+++ b/kernel/mm/mm.h
@@ -56,6 +56,7 @@ int mm_map(u32_t virtual_address, u32_t physical_address,
 
 u32_t mm_early_page_alloc();
 u32_t mm_page_alloc();
+u32_t mm_early_vpage_alloc();
 
 void mm_print_memory_map();