Handout

arch/context.asm

@@ -0,0 +1,20 @@
+[SECTION .text]
+[GLOBAL context_switch]
+[GLOBAL context_launch]
+[GLOBAL fake_systemv_abi]
+
+; context_switch saves the registers in the current context structure
+; and populates the registers from the the next context.
+align 16
+context_switch:
+
+; context_launch populates the register set from the next context structure.
+; It does not save the current registers.
+align 16 ; When only one parameter is used for `align`, it will use NOP
+context_launch:
+
+; fake_systemv_abi is used to populate the volatile argument registers used by the systemv abi (rdi, rsi, ...)
+; with values from the non-volatile registers saved within the thread context (r15, r14, ...)
+align 16
+fake_systemv_abi:
+