massive memory problem averted: we were just being stupid like usual

kernel-rs/src/arch/x86/boot.asm

@@ -11,7 +11,6 @@ start:
 	push ebx
 
 	call check_multiboot
-
 	call set_up_page_tables
 
 	; load the new gdt
@@ -36,6 +35,10 @@ set_up_page_tables:
 	mov eax, 0b10000011 ; huge + present + writable
 	mov [p2_table], eax ; map first entry
 
+	mov eax, 0b10000011 ; huge + present + writable
+	or eax, 0x400000	; 4MB
+	mov [p2_table + 4], eax ; map second entry
+
 	mov eax, p2_table
 	mov cr3, eax
 	ret
@@ -55,7 +58,7 @@ align 4096
 p2_table:
 	resb 4096
 stack_bottom:
-	resb 4096 * 4
+	resb 4096 * 3
 stack_top:
 
 section .gdt

kernel-rs/src/arch/x86/idt.rs

@@ -53,5 +53,6 @@ pub fn init() {
     //     .expect("could not allocate double fault stack");
     // println!("DF stack: {:#?}", double_fault_stack);
     // flush!();
+
     IDT.load();
 }

kernel-rs/src/arch/x86/interrupt/exception.rs

@@ -69,6 +69,9 @@ pub extern "x86-interrupt" fn page_fault(
     println!("Error code: {:?}", code);
     println!("{:#?}", stack_frame);
     flush!();
+    unsafe {
+        asm!("hlt");
+    }
 }
 
 exception!(x87_fpu, {});

kernel-rs/src/arch/x86/linker.ld

@@ -43,12 +43,6 @@ SECTIONS {
 		. = ALIGN(4K);
 	}
 
-	.bss :
-	{
-		*(.bss .bss.*)
-		. = ALIGN(4K);
-	}
-
 	.gdt :
 	{
 		*(.gdt)
@@ -66,4 +60,10 @@ SECTIONS {
 		*(.got.plt)
 		. = ALIGN(4K);
 	}
+
+	.bss :
+	{
+		*(.bss .bss.*)
+		. = ALIGN(4K);
+	}
 }

kernel-rs/src/arch/x86/mod.rs

@@ -17,6 +17,10 @@ pub unsafe extern "C" fn x86_rust_start(multiboot_info_addr: usize) {
     // parse multiboot2 info
     let boot_info = multiboot2::load(multiboot_info_addr);
 
+    // println!("{:?}", boot_info);
+    // flush!();
+    // asm!("hlt");
+
     // ACPI must be intialized BEFORE paging is active
     if let Some(rsdp) = boot_info.rsdp_v2_tag() {
         acpi::load(rsdp).expect("ACPI failed");
@@ -26,15 +30,28 @@ pub unsafe extern "C" fn x86_rust_start(multiboot_info_addr: usize) {
         acpi::init().expect("ACPI failed");
     }
 
-    // fill and load idt (exceptions + irqs)
-    idt::init();
-
     // set up physical allocator
     ::memory::init(&boot_info);
 
-    // set up virtual mapping
+    // let memory_map_tag = boot_info.memory_map_tag().expect("Memory map tag required");
+    // println!("memory areas:");
+    // for area in memory_map_tag.memory_areas() {
+    //     println!(
+    //         "    start: {:#x}, end: {:#x} length: {:#x}",
+    //         area.start_address(),
+    //         area.end_address(),
+    //         area.size()
+    //     );
+    // }
+    // flush!();
+    // asm!("hlt");
+
+    // set up virtual addressing (paging)
     let mut active_table = paging::init(&boot_info);
 
+    // fill and load idt (exceptions + irqs)
+    idt::init();
+
     // set up heap
     ::allocator::init(&mut active_table);
 

kernel-rs/src/arch/x86/paging/mapper.rs

@@ -11,7 +11,7 @@ use super::table::RecTable;
 pub const P2: *mut PageTable = 0xffff_f000 as *mut _;
 
 pub struct Mapper {
-    p2: Unique<PageTable>,
+    pub p2: Unique<PageTable>,
 }
 
 impl Mapper {

kernel-rs/src/arch/x86/paging/mod.rs

@@ -101,6 +101,12 @@ impl InactivePageTable {
         temporary_page: &mut TemporaryPage,
     ) -> InactivePageTable {
         {
+            println!("mapping temp page:");
+            println!("frame: {:?}", frame);
+            flush!();
+            // unsafe {
+            //     asm!("hlt");
+            // }
             let table = temporary_page.map_table_frame(frame.clone(), active_table);
 
             table.zero();

kernel-rs/src/console.rs

@@ -117,7 +117,7 @@ fn print_line(line: &[u8], address: usize) {
 }
 
 /// Print the kernel stack
-fn print_stack() -> Result<(), &'static str> {
+pub fn print_stack() -> Result<(), &'static str> {
     let esp: usize;
     let ebp: usize;
     unsafe { asm!("" : "={esp}"(esp), "={ebp}"(ebp):::) };

kernel-rs/src/lib.rs

@@ -81,7 +81,7 @@ pub extern "C" fn panic_fmt(fmt: core::fmt::Arguments, file: &'static str, line:
     loop {}
 }
 
-pub const HEAP_START: usize = (1 << 22); //first entry of p2
+pub const HEAP_START: usize = (2 << 22); //third entry of p2
 pub const HEAP_SIZE: usize = 10 * 4096 * 8; //~ 100 KiB
 
 #[global_allocator]

kernel-rs/src/memory/bump.rs

@@ -58,6 +58,12 @@ impl FrameAllocator for BumpFrameAllocator {
         if count == 0 {
             return None;
         };
+        // println!("allocate {}", count);
+        // println!("kstart {:?}", self.kernel_start);
+        // println!("kend {:?}", self.kernel_end);
+        // println!("multiboot start {:?}", self.multiboot_start);
+        // println!("multiboot end {:?}", self.multiboot_end);
+        // flush!();
         if let Some(area) = self.current_area {
             let start_frame = PhysFrame {
                 number: self.next_free_frame.number,
@@ -68,6 +74,7 @@ impl FrameAllocator for BumpFrameAllocator {
 
             let current_area_last_frame =
                 PhysFrame::containing_address(PhysAddr::new(area.end_address() as u32));
+
             if end_frame > current_area_last_frame {
                 // all frames are taken in this area
                 self.choose_next_area();

kernel-rs/src/memory/mod.rs

@@ -46,6 +46,20 @@ pub fn init(boot_info: &multiboot2::BootInformation) {
         memory_map_tag.memory_areas(),
     );
 
+    println!("memory areas from the f allocator:");
+    for area in memory_map_tag.memory_areas() {
+        println!(
+            "    start: {:#x}, end: {:#x} length: {:#x}",
+            area.start_address(),
+            area.end_address(),
+            area.size()
+        );
+    }
+    flush!();
+    // unsafe {
+    //     asm!("hlt");
+    // }
+
     let frame_allocator = RecycleAllocator::new(bump_allocator);
 
     // let stack_allocator = {

kernel-rs/x86

@@ -1 +1 @@
-Subproject commit b61535ecda89a6588a2c092dfa3bfbcc7f841575
+Subproject commit ae98bfcd4f30217a4bfe944549d222bb07f81deb