src/arch/riscv32.rs

@@ -44,7 +44,7 @@
 use core::mem;
 use stack::Stack;
 
-pub const STACK_ALIGNMENT: usize = 4096;
+pub const STACK_ALIGNMENT: usize = 16;
 
 #[derive(Debug, Clone, Copy)]
 #[repr(transparent)]
@@ -159,12 +159,6 @@ pub unsafe fn swap(arg: usize, new_sp: StackPointer,
     // Just pass a dummy pointer if we aren't linking the stack
     &mut dummy
   };
-  let stack_limit = if let Some(new_stack) = new_stack {
-    new_stack.limit() as *mut usize
-  } else {
-    // Stack should not reach all the way to address 0
-    0 as *mut usize
-  };
 
   #[naked]
   unsafe extern "C" fn trampoline() {
@@ -180,9 +174,6 @@ pub unsafe fn swap(arg: usize, new_sp: StackPointer,
         .cfi_offset fp, 4
         .cfi_offset ra, 0
 
-        # Perform environment call to modify the PMP regions
-        ecall
-
         # Link the call stacks together by writing the current stack bottom
         # address to the CFA slot in the new stack.
         sw      sp, 0(a3)
@@ -218,7 +209,6 @@ pub unsafe fn swap(arg: usize, new_sp: StackPointer,
       "{a0}" (arg)
       "{a2}" (new_sp.0)
       "{a3}" (new_cfa)
-      "{a7}" (stack_limit)
     :/*"zero",*/"ra",/*"sp","gp","tp",*/"t0","t1","t2",
     /*"fp",*/"s1",/*"a0", "a1"*/"a2", "a3", "a4", "a5",
       "a6", "a7", "s2",  "s3",  "s4", "s5", "s6", "s7",