/*
Copyright Oliver Kowalke 2009.
Copyright Thomas Sailer 2013.
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt)
*/
/**************************************************************************************
* *
* ---------------------------------------------------------------------------------- *
* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | *
* ---------------------------------------------------------------------------------- *
* | 0x0 | 0x4 | 0x8 | 0xc | 0x10 | 0x14 | 0x18 | 0x1c | *
* ---------------------------------------------------------------------------------- *
* | fbr_strg | fc_dealloc | limit | base | *
* ---------------------------------------------------------------------------------- *
* ---------------------------------------------------------------------------------- *
* | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | *
* ---------------------------------------------------------------------------------- *
* | 0x20 | 0x24 | 0x28 | 0x2c | 0x30 | 0x34 | 0x38 | 0x3c | *
* ---------------------------------------------------------------------------------- *
* | R12 | R13 | R14 | R15 | *
* ---------------------------------------------------------------------------------- *
* ---------------------------------------------------------------------------------- *
* | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | *
* ---------------------------------------------------------------------------------- *
* | 0xe40 | 0x44 | 0x48 | 0x4c | 0x50 | 0x54 | 0x58 | 0x5c | *
* ---------------------------------------------------------------------------------- *
* | RDI | RSI | RBX | RBP | *
* ---------------------------------------------------------------------------------- *
* ---------------------------------------------------------------------------------- *
* | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | *
* ---------------------------------------------------------------------------------- *
* | 0x60 | 0x64 | 0x68 | 0x6c | 0x70 | 0x74 | 0x78 | 0x7c | *
* ---------------------------------------------------------------------------------- *
* | hidden | RIP | EXIT | parameter area | *
* ---------------------------------------------------------------------------------- *
* ---------------------------------------------------------------------------------- *
* | 32 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | *
* ---------------------------------------------------------------------------------- *
* | 0x80 | 0x84 | 0x88 | 0x8c | 0x90 | 0x94 | 0x98 | 0x9c | *
* ---------------------------------------------------------------------------------- *
* | parameter area | FCTX | *
* ---------------------------------------------------------------------------------- *
* ---------------------------------------------------------------------------------- *
* | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | *
* ---------------------------------------------------------------------------------- *
* | 0xa0 | 0xa4 | 0xa8 | 0xac | 0xb0 | 0xb4 | 0xb8 | 0xbc | *
* ---------------------------------------------------------------------------------- *
* | DATA | | | | *
* ---------------------------------------------------------------------------------- *
* *
* ***********************************************************************************/
.file "make_x86_64_ms_pe_gas.asm"
.text
.p2align 4,,15
.globl make_fcontext
.def make_fcontext; .scl 2; .type 32; .endef
.seh_proc make_fcontext
make_fcontext:
.seh_endprologue
/* first arg of make_fcontext() == top of context-stack */
movq %rcx, %rax
/* shift address in RAX to lower 16 byte boundary */
/* == pointer to fcontext_t and address of context stack */
andq $-16, %rax
/* reserve space for context-data on context-stack */
/* on context-function entry: (RSP -0x8) % 16 == 0 */
leaq -0xb8(%rax), %rax
/* third arg of make_fcontext() == address of context-function */
movq %r8, 0x68(%rax)
/* first arg of make_fcontext() == top of context-stack */
/* save top address of context stack as 'base' */
movq %rcx, 0x18(%rax)
/* second arg of make_fcontext() == size of context-stack */
/* negate stack size for LEA instruction (== substraction) */
negq %rdx
/* compute bottom address of context stack (limit) */
leaq (%rcx,%rdx), %rcx
/* save bottom address of context stack as 'limit' */
movq %rcx, 0x10(%rax)
/* save address of context stack limit as 'dealloction stack' */
movq %rcx, 0x8(%rax)
/* compute address of transport_t */
leaq 0x98(%rax), %rcx
/* store address of transport_t in hidden field */
movq %rcx, 0x60(%rax)
/* compute abs address of label finish */
leaq finish(%rip), %rcx
/* save address of finish as return-address for context-function */
/* will be entered after context-function returns */
movq %rcx, 0x70(%rax)
ret /* return pointer to context-data */
finish:
/* 32byte shadow-space for _exit() */
andq $-32, %rsp
/* 32byte shadow-space for _exit() are */
/* already reserved by make_fcontext() */
/* exit code is zero */
xorq %rcx, %rcx
/* exit application */
call _exit
hlt
.seh_endproc
.def _exit; .scl 2; .type 32; .endef /* standard C library function */
.section .drectve
.ascii " -export:\"make_fcontext\""