zephyr/scripts/gen_syscall_header.py

167 lines
4.9 KiB
Python
Executable File

#!/usr/bin/env python3
#
# Copyright (c) 2017 Intel Corporation
#
# SPDX-License-Identifier: Apache-2.0
import sys
from enum import Enum
class Retval(Enum):
VOID = 0
U32 = 1
U64 = 2
def gen_macro(ret, argc):
if ret == Retval.VOID:
suffix = "_VOID"
elif ret == Retval.U64:
suffix = "_RET64"
else:
suffix = ""
sys.stdout.write("K_SYSCALL_DECLARE%d%s(id, name" % (argc, suffix))
if (ret != Retval.VOID):
sys.stdout.write(", ret")
for i in range(argc):
sys.stdout.write(", t%d, p%d" % (i, i))
sys.stdout.write(")")
def gen_fn(ret, argc, name, extern=False):
sys.stdout.write("\t%s %s %s(" %
(("extern" if extern else "static inline"),
("ret" if ret != Retval.VOID else "void"), name))
if argc == 0:
sys.stdout.write("void")
else:
for i in range(argc):
sys.stdout.write("t%d p%d" % (i, i))
if i != (argc - 1):
sys.stdout.write(", ")
sys.stdout.write(")")
def tabs(count):
sys.stdout.write("\t" * count)
def gen_make_syscall(ret, argc, tabcount):
tabs(tabcount)
# The core kernel is built with the --no-whole-archive linker option.
# For all the individual .o files which make up the kernel, if there
# are no external references to symbols within these object files,
# everything in the object file is dropped.
#
# This has a subtle interaction with system call handlers. If an object
# file has system call handler inside it, and nothing else in the
# object file is referenced, then the linker will prefer the weak
# version of the handler in the generated syscall_dispatch.c. The
# user will get an "unimplemented system call" error if the associated
# system call for that handler is made.
#
# Fix this by making a fake reference to the handler function at the
# system call site. The address gets stored inside a special section
# "hndlr_ref". This is enough to prevent the handlers from being
# dropped, and the hndlr_ref section is itself dropped from the binary
# from gc-sections; these references will not consume space.
sys.stdout.write(
"static _GENERIC_SECTION(hndlr_ref) __used void *href = (void *)&_handler_##name; \\\n")
tabs(tabcount)
if (ret != Retval.VOID):
sys.stdout.write("return (ret)")
else:
sys.stdout.write("return (void)")
if (argc <= 6 and ret != Retval.U64):
sys.stdout.write("_arch")
sys.stdout.write("_syscall%s_invoke%d(" %
(("_ret64" if ret == Retval.U64 else ""), argc))
for i in range(argc):
sys.stdout.write("(u32_t)p%d, " % (i))
sys.stdout.write("id); \\\n")
def gen_call_impl(ret, argc):
if (ret != Retval.VOID):
sys.stdout.write("return ")
sys.stdout.write("_impl_##name(")
for i in range(argc):
sys.stdout.write("p%d" % (i))
if i != (argc - 1):
sys.stdout.write(", ")
sys.stdout.write("); \\\n")
def newline():
sys.stdout.write(" \\\n")
def gen_defines_inner(ret, argc, kernel_only=False, user_only=False):
sys.stdout.write("#define ")
gen_macro(ret, argc)
newline()
if not user_only:
gen_fn(ret, argc, "_impl_##name", extern=True)
sys.stdout.write(";")
newline()
gen_fn(ret, argc, "name")
newline()
sys.stdout.write("\t{")
newline()
if kernel_only:
sys.stdout.write("\t\t")
gen_call_impl(ret, argc)
elif user_only:
gen_make_syscall(ret, argc, 2)
else:
sys.stdout.write("\t\tif (_is_user_context()) {")
newline()
gen_make_syscall(ret, argc, 3)
sys.stdout.write("\t\t} else {")
newline()
# Prevent memory access issues if the implementation function gets
# inlined
sys.stdout.write("\t\t\tcompiler_barrier();")
newline()
sys.stdout.write("\t\t\t")
gen_call_impl(ret, argc)
sys.stdout.write("\t\t}")
newline()
sys.stdout.write("\t}\n\n")
def gen_defines(argc, kernel_only=False, user_only=False):
gen_defines_inner(Retval.VOID, argc, kernel_only, user_only)
gen_defines_inner(Retval.U32, argc, kernel_only, user_only)
gen_defines_inner(Retval.U64, argc, kernel_only, user_only)
sys.stdout.write(
"/* Auto-generated by gen_syscall_header.py, do not edit! */\n\n")
sys.stdout.write("#ifndef GEN_SYSCALL_H\n#define GEN_SYSCALL_H\n\n")
sys.stdout.write("#include <syscall.h>\n")
for i in range(11):
sys.stdout.write(
"#if !defined(CONFIG_USERSPACE) || defined(__ZEPHYR_SUPERVISOR__)\n")
gen_defines(i, kernel_only=True)
sys.stdout.write("#elif defined(__ZEPHYR_USER__)\n")
gen_defines(i, user_only=True)
sys.stdout.write("#else /* mixed kernel/user macros */\n")
gen_defines(i)
sys.stdout.write("#endif /* mixed kernel/user macros */\n\n")
sys.stdout.write("#endif /* GEN_SYSCALL_H */\n")