Added a constant describing the kernel's initial stack

This also makes the stack bounds consistent with the other address
range constants, in that the start is the smallest address in the
range and the end is the largest address in the range.

Author: SlyMarbo

kernel/src/memory/constants.rs

@@ -72,12 +72,16 @@ const KERNEL_STACK_GUARD_END: VirtAddr = const_virt_addr(0xffff_8000_5554_ffff a
 
 /// KERNEL_STACK is the virtual address of the kernel's stack.
 ///
-/// Note that the stack counts downwards, so the start address is larger than
-/// the end address.
+/// Note that even though the stack counts downwards, we use the smaller address as
+/// the start address and the larger address as the end address.
 ///
-pub const KERNEL_STACK: VirtAddrRange = VirtAddrRange::new(KERNEL_STACK_END, KERNEL_STACK_START);
-const KERNEL_STACK_START: VirtAddr = const_virt_addr(0xffff_8000_5d5c_ffff as u64);
-const KERNEL_STACK_END: VirtAddr = const_virt_addr(0xffff_8000_5555_0000 as u64);
+pub const KERNEL_STACK: VirtAddrRange = VirtAddrRange::new(KERNEL_STACK_START, KERNEL_STACK_END);
+const KERNEL_STACK_START: VirtAddr = const_virt_addr(0xffff_8000_5555_0000 as u64);
+const KERNEL_STACK_END: VirtAddr = const_virt_addr(0xffff_8000_5d5c_ffff as u64);
+pub const KERNEL_STACK_0: VirtAddrRange =
+    VirtAddrRange::new(KERNEL_STACK_0_START, KERNEL_STACK_0_END);
+const KERNEL_STACK_0_START: VirtAddr = KERNEL_STACK_START;
+const KERNEL_STACK_0_END: VirtAddr = const_virt_addr(0xffff_8000_555c_ffff as u64);
 pub const KERNEL_STACK_1_START: VirtAddr = const_virt_addr(0xffff_8000_555d_0000 as u64);
 
 /// MMIO_SPACE is the virtual address space used for accessing

kernel/src/memory/mod.rs

@@ -28,7 +28,8 @@ pub mod vmm;
 
 pub use crate::memory::constants::{
     phys_to_virt_addr, VirtAddrRange, BOOT_INFO, KERNEL_BINARY, KERNEL_HEAP, KERNEL_STACK,
-    KERNEL_STACK_GUARD, MMIO_SPACE, NULL_PAGE, PHYSICAL_MEMORY, PHYSICAL_MEMORY_OFFSET, USERSPACE,
+    KERNEL_STACK_0, KERNEL_STACK_GUARD, MMIO_SPACE, NULL_PAGE, PHYSICAL_MEMORY,
+    PHYSICAL_MEMORY_OFFSET, USERSPACE,
 };
 
 // PML4 functionality.