Merge "Romlib makefile refactoring and script rewriting" into integration
diff --git a/docs/components/romlib-design.rst b/docs/components/romlib-design.rst
index a70ed17..d8bc89c 100644
--- a/docs/components/romlib-design.rst
+++ b/docs/components/romlib-design.rst
@@ -42,7 +42,7 @@
::
- reserved reserved
+ reserved
The reserved spaces can be used to add more functions in the future without
affecting the order and location of functions already existing in the jump
@@ -71,29 +71,41 @@
The "library at ROM" contains a necessary init function that initialises the
global variables defined by the functions inside "library at ROM".
-Scripts
-~~~~~~~
+Script
+~~~~~~
-There are several scripts that generate the necessary files for the "library at
-ROM" to work:
+There is a ``romlib_generate.py`` Python script that generates the necessary
+files for the "library at ROM" to work. It implements multiple functions:
-1. ``gentbl.sh`` - Generates the jump table by parsing the index file.
+1. ``romlib_generate.py gentbl [args]`` - Generates the jump table by parsing
+ the index file.
-2. ``genvar.sh`` - Generates the jump table global variable (**not** the jump
- table itself) with the absolute address in ROM. This global variable is,
- basically, a pointer to the jump table.
+2. ``romlib_generator.py genvar [args]`` - Generates the jump table global
+ variable (**not** the jump table itself) with the absolute address in ROM.
+ This global variable is, basically, a pointer to the jump table.
-3. ``genwrappers.sh`` - Generates a wrapper function for each entry in the index
- file except for the ones that contain the keyword ``patch``. The generated
- wrapper file is called ``<lib>_<fn_name>.S``.
+3. ``romlib_generator.py genwrappers [args]`` - Generates a wrapper function for
+ each entry in the index file except for the ones that contain the keyword
+ ``patch``. The generated wrapper file is called ``<fn_name>.s``.
+
+4. ``romlib_generator.py pre [args]`` - Preprocesses the index file which means
+ it resolves all the include commands in the file recursively. It can also
+ generate a dependency file of the included index files which can be directly
+ used in makefiles.
+
+Each ``romlib_generate.py`` function has its own manual which is accessible by
+runing ``romlib_generator.py [function] --help``.
+
+``romlib_generate.py`` requires Python 3 environment.
+
Patching of functions in library at ROM
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The ``genwrappers.sh`` script does not generate wrappers for the entries in the
-index file that contain the keyword ``patch``. Thus, it allows calling the
-function from the actual library by breaking the link to the "library at ROM"
-version of this function.
+The ``romlib_generator.py genwrappers`` does not generate wrappers for the
+entries in the index file that contain the keyword ``patch``. Thus, it allows
+calling the function from the actual library by breaking the link to the
+"library at ROM" version of this function.
The calling sequence for a patched function is as follows:
@@ -117,12 +129,6 @@
USE_ROMLIB=1 \
all fip
-Known issue
------------
-When building library at ROM, a clean build is always required. This is
-necessary when changes are made to the index files, e.g. adding new functions,
-patching existing ones etc.
-
--------------
*Copyright (c) 2019, Arm Limited. All rights reserved.*
diff --git a/lib/romlib/Makefile b/lib/romlib/Makefile
index bc05d0f..60c1458 100644
--- a/lib/romlib/Makefile
+++ b/lib/romlib/Makefile
@@ -5,9 +5,11 @@
#
AS = $(CROSS_COMPILE)as
+AR = $(CROSS_COMPILE)ar
LD = $(CROSS_COMPILE)ld
OC = $(CROSS_COMPILE)objcopy
CPP = $(CROSS_COMPILE)cpp
+ROMLIB_GEN = ./romlib_generator.py
BUILD_DIR = ../../$(BUILD_PLAT)/romlib
LIB_DIR = ../../$(BUILD_PLAT)/lib
WRAPPER_DIR = ../../$(BUILD_PLAT)/libwrapper
@@ -17,6 +19,11 @@
OBJS = $(BUILD_DIR)/jmptbl.o $(BUILD_DIR)/init.o
MAPFILE = ../../$(BUILD_PLAT)/romlib/romlib.map
+ifneq ($(PLAT_DIR),)
+ WRAPPER_SOURCES = $(shell $(ROMLIB_GEN) genwrappers -b $(WRAPPER_DIR) --list ../../$(PLAT_DIR)/jmptbl.i)
+ WRAPPER_OBJS = $(WRAPPER_SOURCES:.s=.o)
+endif
+
V ?= 0
ifeq ($(V),0)
Q := @
@@ -61,19 +68,31 @@
$(WRAPPER_DIR)/jmpvar.s: $(BUILD_DIR)/romlib.elf
@echo " VAR $@"
- $(Q)./genvar.sh -o $@ $(BUILD_DIR)/romlib.elf
+ $(Q)$(ROMLIB_GEN) genvar --output $@ $<
-$(LIB_DIR)/libwrappers.a: $(BUILD_DIR)/jmptbl.i $(WRAPPER_DIR)/jmpvar.o
+$(LIB_DIR)/libwrappers.a: $(WRAPPER_DIR)/jmpvar.o $(WRAPPER_OBJS)
@echo " AR $@"
- $(Q)./genwrappers.sh -b $(WRAPPER_DIR) -o $@ --bti=$(ENABLE_BTI) --asflags=$(ASFLAGS) $(BUILD_DIR)/jmptbl.i
+ $(Q)$(AR) -rc $@ $(WRAPPER_DIR)/jmpvar.o $(WRAPPER_OBJS)
-$(BUILD_DIR)/jmptbl.i: $(BUILD_DIR)/jmptbl.s
+$(BUILD_DIR)/jmptbl.i: ../../$(PLAT_DIR)/jmptbl.i
+ @echo " PRE $@"
+ $(Q)$(ROMLIB_GEN) pre --output $@ --deps $(BUILD_DIR)/jmptbl.d $<
-$(BUILD_DIR)/jmptbl.s: ../../$(PLAT_DIR)/jmptbl.i
+$(BUILD_DIR)/wrappers.stamp: $(BUILD_DIR)/jmptbl.i
+ @echo " WRP $<"
+ $(Q)$(ROMLIB_GEN) genwrappers --bti=$(ENABLE_BTI) -b $(WRAPPER_DIR) $<
+ @touch $@
+
+$(WRAPPER_SOURCES): $(BUILD_DIR)/wrappers.stamp
+
+$(WRAPPER_OBJS): $(WRAPPER_SOURCES) $(BUILD_DIR)/wrappers.stamp
+
+$(BUILD_DIR)/jmptbl.s: $(BUILD_DIR)/jmptbl.i
@echo " TBL $@"
- $(Q)./gentbl.sh -o $@ -b $(BUILD_DIR) --bti=$(ENABLE_BTI) ../../$(PLAT_DIR)/jmptbl.i
+ $(Q)$(ROMLIB_GEN) gentbl --output $@ --bti=$(ENABLE_BTI) $<
clean:
@rm -f $(BUILD_DIR)/*
-include $(BUILD_DIR)/romlib.d
+-include $(BUILD_DIR)/jmptbl.d
diff --git a/lib/romlib/gentbl.sh b/lib/romlib/gentbl.sh
deleted file mode 100755
index bfb1ec3cf..0000000
--- a/lib/romlib/gentbl.sh
+++ /dev/null
@@ -1,66 +0,0 @@
-#!/bin/sh
-# Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
-#
-# SPDX-License-Identifier: BSD-3-Clause
-
-set -e
-
-output=jmptbl.s
-build=.
-
-for i
-do
- case $i in
- -o)
- output=$2
- shift 2
- ;;
- -b)
- build=$2
- shift 2
- ;;
- --bti=*)
- enable_bti=$(echo $1 | sed 's/--bti=\(.*\)/\1/')
- shift 1
- ;;
- --)
- shift
- break
- ;;
- -*)
- echo usage: gentbl.sh [-o output] [-b dir] file ... >&2
- exit 1
- ;;
- esac
-done
-
-tmp=`mktemp`
-trap "rm -f $$.tmp" EXIT INT QUIT
-rm -f $output
-
-# Pre-process include files
-awk '!/^$/ && !/[:blank:]*#.*/{
-if (NF == 2 && $1 == "include") {
- while ((getline line < $2) > 0)
- if (line !~ /^$/ && line !~ /[:blank:]*#.*/)
- print line
- close($2)
-} else
- print
-}' "$@" |
-awk -v OFS="\t" '
-BEGIN{print "#index\tlib\tfunction\t[patch]"}
-{print NR-1, $0}' | tee $build/jmptbl.i |
-awk -v OFS="\n" -v BTI=$enable_bti '
-BEGIN {print "\t.text",
- "\t.globl\tjmptbl",
- "jmptbl:"}
- {sub(/[:blank:]*#.*/,"")}
-!/^$/ {
- if (BTI == 1)
- print "\tbti\tj"
- if ($3 == "reserved")
- print "\t.word\t0x0"
- else
- print "\tb\t" $3}' > $$.tmp &&
-mv $$.tmp $output
diff --git a/lib/romlib/genvar.sh b/lib/romlib/genvar.sh
deleted file mode 100755
index a3e2cdf..0000000
--- a/lib/romlib/genvar.sh
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/bin/sh
-# Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
-#
-# SPDX-License-Identifier: BSD-3-Clause
-
-set -e
-
-output=jmpvar.s
-for i
-do
- case $i in
- -o)
- output=$2
- shift 2
- ;;
- --)
- shift
- break
- ;;
- -*)
- echo usage: genvar.sh [-o output] file... >&2
- ;;
- esac
-done
-
-tmp=`mktemp`
-trap "rm -f $tmp" EXIT INT QUIT
-
-nm -a "$@" |
-awk -v OFS="\n" '
-$3 == ".text" {print "\t.data",
- "\t.globl\tjmptbl",
- "\t.align\t4",
- "jmptbl:\t.quad\t0x" $1}' > $tmp
-
-mv $tmp $output
diff --git a/lib/romlib/genwrappers.sh b/lib/romlib/genwrappers.sh
deleted file mode 100755
index e092548..0000000
--- a/lib/romlib/genwrappers.sh
+++ /dev/null
@@ -1,71 +0,0 @@
-#!/bin/sh
-# Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
-#
-# SPDX-License-Identifier: BSD-3-Clause
-
-set -e
-
-build=.
-out=output.a
-
-for i
-do
- case $i in
- -o)
- out=$2
- shift 2
- ;;
- -b)
- build=$2
- shift 2
- ;;
- --bti=*)
- enable_bti=$(echo $1 | sed 's/--bti=\(.*\)/\1/')
- shift 1
- ;;
- --asflags=*)
- asflags=$(echo $1 | sed 's/--asflags=\(.*\)/\1/')
- shift 1
- ;;
- --)
- shift
- break
- ;;
- -*)
- echo usage: genwrappers.sh [-o output] [-b dir] file ... >&2
- exit 1
- ;;
- esac
-done
-
-awk -v BTI=$enable_bti '
-{sub(/[:blank:]*#.*/,"")}
-!/^$/ && $NF != "patch" && $NF != "reserved" {
- if (BTI == 1)
- print $1*8, $2, $3
- else
- print $1*4, $2, $3}' "$@" |
-while read idx lib sym
-do
- file=$build/${lib}_$sym
-
- cat <<EOF > $file.s
- .globl $sym
-$sym:
-EOF
-if [ $enable_bti = 1 ]
-then
- echo "\tbti\tjc" >> $file.s
-fi
- cat <<EOF >> $file.s
- ldr x17, =jmptbl
- mov x16, #$idx
- ldr x17, [x17]
- add x16, x16, x17
- br x16
-EOF
-
- ${CROSS_COMPILE}as ${asflags} -o $file.o $file.s
-done
-
-${CROSS_COMPILE}ar -rc $out $build/*.o
diff --git a/lib/romlib/romlib_generator.py b/lib/romlib/romlib_generator.py
new file mode 100755
index 0000000..0682dd4
--- /dev/null
+++ b/lib/romlib/romlib_generator.py
@@ -0,0 +1,277 @@
+#!/usr/bin/env python3
+# Copyright (c) 2019, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""
+This module contains a set of classes and a runner that can generate code for the romlib module
+based on the templates in the 'templates' directory.
+"""
+
+import argparse
+import os
+import re
+import subprocess
+import string
+import sys
+
+class IndexFileParser:
+ """
+ Parses the contents of the index file into the items and dependencies variables. It
+ also resolves included files in the index files recursively with circular inclusion detection.
+ """
+
+ def __init__(self):
+ self.items = []
+ self.dependencies = {}
+ self.include_chain = []
+
+ def add_dependency(self, parent, dependency):
+ """ Adds a dependency into the dependencies variable. """
+ if parent in self.dependencies:
+ self.dependencies[parent].append(dependency)
+ else:
+ self.dependencies[parent] = [dependency]
+
+ def get_dependencies(self, parent):
+ """ Gets all the recursive dependencies of a parent file. """
+ parent = os.path.normpath(parent)
+ if parent in self.dependencies:
+ direct_deps = self.dependencies[parent]
+ deps = direct_deps
+ for direct_dep in direct_deps:
+ deps += self.get_dependencies(direct_dep)
+ return deps
+
+ return []
+
+ def parse(self, file_name):
+ """ Opens and parses index file. """
+ file_name = os.path.normpath(file_name)
+
+ if file_name not in self.include_chain:
+ self.include_chain.append(file_name)
+ self.dependencies[file_name] = []
+ else:
+ raise Exception("Circular dependency detected: " + file_name)
+
+ with open(file_name, "r") as index_file:
+ for line in index_file.readlines():
+ line_elements = line.split()
+
+ if line.startswith("#") or not line_elements:
+ # Comment or empty line
+ continue
+
+ if line_elements[0] == "reserved":
+ # Reserved slot in the jump table
+ self.items.append({"type": "reserved"})
+ elif line_elements[0] == "include" and len(line_elements) > 1:
+ # Include other index file
+ included_file = os.path.normpath(line_elements[1])
+ self.add_dependency(file_name, included_file)
+ self.parse(included_file)
+ elif len(line_elements) > 1:
+ # Library function
+ library_name = line_elements[0]
+ function_name = line_elements[1]
+ patch = bool(len(line_elements) > 2 and line_elements[2] == "patch")
+
+ self.items.append({"type": "function", "library_name": library_name,
+ "function_name": function_name, "patch": patch})
+ else:
+ raise Exception("Invalid line: '" + line + "'")
+
+ self.include_chain.pop()
+
+class RomlibApplication:
+ """ Base class of romlib applications. """
+ TEMPLATE_DIR = os.path.dirname(os.path.realpath(__file__)) + "/templates/"
+
+ def __init__(self, prog):
+ self.args = argparse.ArgumentParser(prog=prog, description=self.__doc__)
+ self.config = None
+
+ def parse_arguments(self, argv):
+ """ Parses the arguments that should come from the command line arguments. """
+ self.config = self.args.parse_args(argv)
+
+ def build_template(self, name, mapping=None, remove_comment=False):
+ """
+ Loads a template and builds it with the defined mapping. Template paths are always relative
+ to this script.
+ """
+
+ with open(self.TEMPLATE_DIR + name, "r") as template_file:
+ if remove_comment:
+ # Removing copyright comment to make the generated code more readable when the
+ # template is inserted multiple times into the output.
+ template_lines = template_file.readlines()
+ end_of_comment_line = 0
+ for index, line in enumerate(template_lines):
+ if line.find("*/") != -1:
+ end_of_comment_line = index
+ break
+ template_data = "".join(template_lines[end_of_comment_line + 1:])
+ else:
+ template_data = template_file.read()
+
+ template = string.Template(template_data)
+ return template.substitute(mapping)
+
+class IndexPreprocessor(RomlibApplication):
+ """ Removes empty and comment lines from the index file and resolves includes. """
+
+ def __init__(self, prog):
+ RomlibApplication.__init__(self, prog)
+
+ self.args.add_argument("-o", "--output", help="Output file", metavar="output",
+ default="jmpvar.s")
+ self.args.add_argument("--deps", help="Dependency file")
+ self.args.add_argument("file", help="Input file")
+
+ def main(self):
+ """
+ After parsing the input index file it generates a clean output with all includes resolved.
+ Using --deps option it also outputs the dependencies in makefile format like gcc's with -M.
+ """
+
+ index_file_parser = IndexFileParser()
+ index_file_parser.parse(self.config.file)
+
+ with open(self.config.output, "w") as output_file:
+ for item in index_file_parser.items:
+ if item["type"] == "function":
+ patch = "\tpatch" if item["patch"] else ""
+ output_file.write(
+ item["library_name"] + "\t" + item["function_name"] + patch + "\n")
+ else:
+ output_file.write("reserved\n")
+
+ if self.config.deps:
+ with open(self.config.deps, "w") as deps_file:
+ deps = [self.config.file] + index_file_parser.get_dependencies(self.config.file)
+ deps_file.write(self.config.output + ": " + " \\\n".join(deps) + "\n")
+
+class TableGenerator(RomlibApplication):
+ """ Generates the jump table by parsing the index file. """
+
+ def __init__(self, prog):
+ RomlibApplication.__init__(self, prog)
+
+ self.args.add_argument("-o", "--output", help="Output file", metavar="output",
+ default="jmpvar.s")
+ self.args.add_argument("--bti", help="Branch Target Identification", type=int)
+ self.args.add_argument("file", help="Input file")
+
+ def main(self):
+ """
+ Inserts the jmptbl definition and the jump entries into the output file. Also can insert
+ BTI related code before entries if --bti option set. It can output a dependency file of the
+ included index files. This can be directly included in makefiles.
+ """
+
+ index_file_parser = IndexFileParser()
+ index_file_parser.parse(self.config.file)
+
+ with open(self.config.output, "w") as output_file:
+ output_file.write(self.build_template("jmptbl_header.S"))
+ bti = "_bti" if self.config.bti == 1 else ""
+
+ for item in index_file_parser.items:
+ template_name = "jmptbl_entry_" + item["type"] + bti + ".S"
+ output_file.write(self.build_template(template_name, item, True))
+
+class WrapperGenerator(RomlibApplication):
+ """
+ Generates a wrapper function for each entry in the index file except for the ones that contain
+ the keyword patch. The generated wrapper file is called <lib>_<fn_name>.s.
+ """
+
+ def __init__(self, prog):
+ RomlibApplication.__init__(self, prog)
+
+ self.args.add_argument("-b", help="Build directory", default=".", metavar="build")
+ self.args.add_argument("--bti", help="Branch Target Identification", type=int)
+ self.args.add_argument("--list", help="Only list assembly files", action="store_true")
+ self.args.add_argument("file", help="Input file")
+
+ def main(self):
+ """
+ Iterates through the items in the parsed index file and builds the template for each entry.
+ """
+
+ index_file_parser = IndexFileParser()
+ index_file_parser.parse(self.config.file)
+
+ bti = "_bti" if self.config.bti == 1 else ""
+ function_offset = 0
+ files = []
+
+ for item_index in range(0, len(index_file_parser.items)):
+ item = index_file_parser.items[item_index]
+
+ if item["type"] == "reserved" or item["patch"]:
+ continue
+
+ asm = self.config.b + "/" + item["function_name"] + ".s"
+ if self.config.list:
+ # Only listing files
+ files.append(asm)
+ else:
+ with open(asm, "w") as asm_file:
+ # The jump instruction is 4 bytes but BTI requires and extra instruction so
+ # this makes it 8 bytes per entry.
+ function_offset = item_index * (8 if self.config.bti else 4)
+
+ item["function_offset"] = function_offset
+ asm_file.write(self.build_template("wrapper" + bti + ".S", item))
+
+ if self.config.list:
+ print(" ".join(files))
+
+class VariableGenerator(RomlibApplication):
+ """ Generates the jump table global variable with the absolute address in ROM. """
+
+ def __init__(self, prog):
+ RomlibApplication.__init__(self, prog)
+
+ self.args.add_argument("-o", "--output", help="Output file", metavar="output",
+ default="jmpvar.s")
+ self.args.add_argument("file", help="Input file")
+
+ def main(self):
+ """
+ Runs nm -a command on the input file and inserts the address of the .text section into the
+ template as the ROM address of the jmp_table.
+ """
+ symbols = subprocess.check_output(["nm", "-a", self.config.file])
+
+ matching_symbol = re.search("([0-9A-Fa-f]+) . \\.text", str(symbols))
+ if not matching_symbol:
+ raise Exception("No '.text' section was found in %s" % self.config.file)
+
+ mapping = {"jmptbl_address": matching_symbol.group(1)}
+
+ with open(self.config.output, "w") as output_file:
+ output_file.write(self.build_template("jmptbl_glob_var.S", mapping))
+
+if __name__ == "__main__":
+ APPS = {"genvar": VariableGenerator, "pre": IndexPreprocessor,
+ "gentbl": TableGenerator, "genwrappers": WrapperGenerator}
+
+ if len(sys.argv) < 2 or sys.argv[1] not in APPS:
+ print("usage: romlib_generator.py [%s] [args]" % "|".join(APPS.keys()), file=sys.stderr)
+ sys.exit(1)
+
+ APP = APPS[sys.argv[1]]("romlib_generator.py " + sys.argv[1])
+ APP.parse_arguments(sys.argv[2:])
+ try:
+ APP.main()
+ sys.exit(0)
+ except FileNotFoundError as file_not_found_error:
+ print(file_not_found_error, file=sys.stderr)
+ except subprocess.CalledProcessError as called_process_error:
+ print(called_process_error.output, file=sys.stderr)
+
+ sys.exit(1)
diff --git a/lib/romlib/templates/jmptbl_entry_function.S b/lib/romlib/templates/jmptbl_entry_function.S
new file mode 100644
index 0000000..a0f8456
--- /dev/null
+++ b/lib/romlib/templates/jmptbl_entry_function.S
@@ -0,0 +1,6 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ b ${function_name}
diff --git a/lib/romlib/templates/jmptbl_entry_function_bti.S b/lib/romlib/templates/jmptbl_entry_function_bti.S
new file mode 100644
index 0000000..d96ee94
--- /dev/null
+++ b/lib/romlib/templates/jmptbl_entry_function_bti.S
@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ bti j
+ b ${function_name}
diff --git a/lib/romlib/templates/jmptbl_entry_reserved.S b/lib/romlib/templates/jmptbl_entry_reserved.S
new file mode 100644
index 0000000..a9b5f18
--- /dev/null
+++ b/lib/romlib/templates/jmptbl_entry_reserved.S
@@ -0,0 +1,6 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ b .
diff --git a/lib/romlib/templates/jmptbl_entry_reserved_bti.S b/lib/romlib/templates/jmptbl_entry_reserved_bti.S
new file mode 100644
index 0000000..a9f0375
--- /dev/null
+++ b/lib/romlib/templates/jmptbl_entry_reserved_bti.S
@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ bti j
+ b .
diff --git a/lib/romlib/templates/jmptbl_glob_var.S b/lib/romlib/templates/jmptbl_glob_var.S
new file mode 100644
index 0000000..d306512
--- /dev/null
+++ b/lib/romlib/templates/jmptbl_glob_var.S
@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ .data
+ .globl jmptbl
+ .align 4
+jmptbl: .quad 0x${jmptbl_address}
diff --git a/lib/romlib/templates/jmptbl_header.S b/lib/romlib/templates/jmptbl_header.S
new file mode 100644
index 0000000..72b8ce5
--- /dev/null
+++ b/lib/romlib/templates/jmptbl_header.S
@@ -0,0 +1,8 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ .text
+ .globl jmptbl
+jmptbl:
diff --git a/lib/romlib/templates/wrapper.S b/lib/romlib/templates/wrapper.S
new file mode 100644
index 0000000..734a68a
--- /dev/null
+++ b/lib/romlib/templates/wrapper.S
@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ .globl ${function_name}
+${function_name}:
+ ldr x17, =jmptbl
+ mov x16, #${function_offset}
+ ldr x17, [x17]
+ add x16, x16, x17
+ br x16
diff --git a/lib/romlib/templates/wrapper_bti.S b/lib/romlib/templates/wrapper_bti.S
new file mode 100644
index 0000000..ba9b11c
--- /dev/null
+++ b/lib/romlib/templates/wrapper_bti.S
@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+ .globl ${function_name}
+${function_name}:
+ bti jc
+ ldr x17, =jmptbl
+ mov x16, #${function_offset}
+ ldr x17, [x17]
+ add x16, x16, x17
+ br x16