Changeset 37b451f7 in mainline for arch/amd64/src/asm_utils.S

Timestamp:

2006-02-07T02:22:44Z (19 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

65640fef

Parents:

dd4d6b0

Message:

Added (finally!) userspace to AMD64.
It does not work on Simics *$U&%&$&*#. Broken simics!!!
There should be probably LEA instead of MOV/ADD, but LEA does not
work in neither qemu nor bochs. Any other simulator to test? :-/

File:

• arch/amd64/src/asm_utils.S (modified) (1 diff)

arch/amd64/src/asm_utils.S

@@ -193 +193 @@
         
 syscall_entry:
-        # TODO: Switch to kernel stack
+        # Switch to hidden gs   
+        swapgs
+
+        # TODO: I would like LEA instead of thes 2 instrs,
+        # why does not it work???
+        mov %gs:0, %r10     # We have a stack in r10
+        addq $0x0ff0, %r10
+        
+        movq %rsp, 0(%r10)  # Save old stack pointer to stack
+        movq %r10, %rsp     # Change to new stack
+        pushq %rcx          # Return address
+        pushq %r11          # Save flags
+
+        # Switch back to remain consistent
+        swapgs 
+
+        movq %r9, %rcx      # Exchange last parameter as a third
         call syscall_handler
-        # Switch back
-        sysret
+        
+        popq %r11
+        popq %rcx
+        movq 0(%rsp), %rsp
+        sysretq
                 
 .data