libfringe/src/init.s

// Copyright (c) 2015, edef <edef@edef.eu>
// See LICENSE file that comes with this distribution.

/// initialise a new context
/// arguments: rdi: stack pointer,
///            rsi: function pointer,
///            rdx, data pointer
///            rcx, stack limit

// switch to the fresh stack
xchg %rsp, %rdi

// save the function pointer, data pointer, and stack limit, respectively
pushq %rsi
pushq %rdx
pushq %rcx

// save the return address, control flow continues at label 1
call 1f
// we arrive here once this context is reactivated (see swap.s)

// restore the stack limit, data pointer, and function pointer, respectively
popq %fs:0x70
popq %rdi
popq %rax

// initialise the frame pointer
movq $$0, %rbp

// call the function pointer with the data pointer (rdi is the first argument)
call *%rax

// crash if it ever returns
ud2

1:
  // save our neatly-setup new stack
  xchg %rsp, %rdi
  // back into Rust-land we go
add license headers to the assembly files 2015-04-16 12:16:23 +08:00			`// Copyright (c) 2015, edef <edef@edef.eu>`
			`// See LICENSE file that comes with this distribution.`

document the assembly 2015-03-27 15:31:02 +08:00			`/// initialise a new context`
			`/// arguments: rdi: stack pointer,`
			`/// rsi: function pointer,`
			`/// rdx, data pointer`
			`/// rcx, stack limit`

			`// switch to the fresh stack`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`xchg %rsp, %rdi`

document the assembly 2015-03-27 15:31:02 +08:00			`// save the function pointer, data pointer, and stack limit, respectively`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`pushq %rsi`
			`pushq %rdx`
			`pushq %rcx`
document the assembly 2015-03-27 15:31:02 +08:00
			`// save the return address, control flow continues at label 1`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`call 1f`
document the assembly 2015-03-27 15:31:02 +08:00			`// we arrive here once this context is reactivated (see swap.s)`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00
document the assembly 2015-03-27 15:31:02 +08:00			`// restore the stack limit, data pointer, and function pointer, respectively`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`popq %fs:0x70`
			`popq %rdi`
			`popq %rax`

document the assembly 2015-03-27 15:31:02 +08:00			`// initialise the frame pointer`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`movq $$0, %rbp`
document the assembly 2015-03-27 15:31:02 +08:00
			`// call the function pointer with the data pointer (rdi is the first argument)`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`call *%rax`
document the assembly 2015-03-27 15:31:02 +08:00
			`// crash if it ever returns`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`ud2`

			`1:`
document the assembly 2015-03-27 15:31:02 +08:00			`// save our neatly-setup new stack`
complete rewrite! featuring 7ns inlineable context switches, no more separately-built assembly objects, and a vastly nicer interface. incontext/outcontext are no more, context switch calls now take a single context structure, which functions as both. everything now also functions without any heap allocations -- for the context setup, only an FnOnce() value is necessary. 2015-01-14 15:31:17 +08:00			`xchg %rsp, %rdi`
document the assembly 2015-03-27 15:31:02 +08:00			`// back into Rust-land we go`