From 533a9e57de8cb74594499f625810ad812359d3fb Mon Sep 17 00:00:00 2001 From: johannst Date: Tue, 29 Sep 2020 04:31:51 +0200 Subject: added basic arm64 support --- lib/arch/arm64/yield.s | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 lib/arch/arm64/yield.s (limited to 'lib/arch/arm64/yield.s') diff --git a/lib/arch/arm64/yield.s b/lib/arch/arm64/yield.s new file mode 100644 index 0000000..63a4051 --- /dev/null +++ b/lib/arch/arm64/yield.s @@ -0,0 +1,42 @@ +# Copyright (c) 2020 Johannes Stoelp + + .arch armv8-a + .section .text, "ax", @progbits + + # extern "C" void yield(const void* new_stack, void* const* old_stack); + # ^^^^^^^^^ ^^^^^^^^^ + # rdi rsi + .global yield + .type yield, @function +yield: + .cfi_startproc + // prologue + stp x29, x30, [sp, -16]! + mov x29, sp + + // push callee saved registers + stp x27, x28, [sp, -16]! + stp x25, x26, [sp, -16]! + stp x23, x24, [sp, -16]! + stp x21, x22, [sp, -16]! + stp x19, x20, [sp, -16]! + + // arg0: x0 holds new stack + // arg1: x1 holds addr to location current stack must be saved + mov x2, sp + str x2, [x1] // save current stack ptr + mov sp, x0 // switch to new stack ptr + + // pop callee saved registers + ldp x19, x20, [sp], 16 + ldp x21, x22, [sp], 16 + ldp x23, x24, [sp], 16 + ldp x25, x26, [sp], 16 + ldp x27, x28, [sp], 16 + + // epilogue + ldp x29, x30, [sp], 16 + + ret + .cfi_endproc + .size yield, .-yield -- cgit v1.2.3