llext: automatically calculate module addresses

Currently LLEXT module starting addresses are hard-coded in their
respective CMakeLists.txt files. This is very wasteful, since it's
unknown in what order modules are loaded, inflexible and not easily
extendible to other platforms. Switch to calculating addresses
automatically based on a single per-platform Kconfig value.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

app/overlays/lnl/module_overlay.conf

@@ -1,3 +1,4 @@
+CONFIG_LIBRARY_BASE_ADDRESS=0xa0688000
 CONFIG_SAMPLE_SMART_AMP=m
 CONFIG_COMP_MIXIN_MIXOUT=m
 CONFIG_COMP_IIR=m

app/overlays/mtl/module_overlay.conf

@@ -1,3 +1,4 @@
+CONFIG_LIBRARY_BASE_ADDRESS=0xa0688000
 CONFIG_SAMPLE_SMART_AMP=m
 CONFIG_COMP_MIXIN_MIXOUT=m
 CONFIG_COMP_IIR=m

scripts/llext_link_helper.py

@@ -28,6 +28,8 @@ def parse_args():
 						help='Object file name')
 	parser.add_argument("-t", "--text-addr", required=True, type=str,
 						help='.text section address')
+	parser.add_argument("-s", "--size-file", required=True, type=str,
+						help='File with stored accumulated size')
 
 	args = parser.parse_args()
 
@@ -43,11 +45,20 @@ def max_alignment(addr, align1, align2):
 	return upper - (upper % align1)
 
 def main():
+	global args
+
 	parse_args()
 
-	elf = ELFFile(open(args.file, 'rb'))
+	# Get the size of the previous module, if this isn't the first one.
+	# It is used to automatically calculate starting address of the current
+	# module.
+	try:
+		with open(args.size_file, 'r') as f_size:
+			size = int(f_size.read().strip(), base = 0)
+	except OSError:
+		size = 0
 
-	text_addr = int(args.text_addr, 0)
+	text_addr = int(args.text_addr, 0) + size
 	text_size = 0
 
 	# File names differ when building shared or relocatable objects
@@ -65,6 +76,8 @@ def main():
 	writable = []
 	readonly = []
 
+	elf = ELFFile(open(args.file, 'rb'))
+
 	# Create an object file with sections grouped by their properties,
 	# similar to how program segments are created: all executable sections,
 	# then all read-only data sections, and eventually all writable data

scripts/llext_offset_calc.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: BSD-3-Clause
+
+# Add rounded new file size to accumulated module size cache
+
+import argparse
+import pathlib
+import os
+
+args = None
+
+def parse_args():
+	global args
+
+	parser = argparse.ArgumentParser(description='Add a file size to a sum in a file')
+
+	parser.add_argument("-i", "--input", required=True, type=str,
+						help='Object file name')
+	parser.add_argument("-s", "--size-file", required=True, type=str,
+						help='File to store accumulated size')
+
+	args = parser.parse_args()
+
+def main():
+	global args
+
+	parse_args()
+
+	f_output = pathlib.Path(args.size_file)
+
+	try:
+		with open(f_output, 'r') as f_size:
+			size = int(f_size.read().strip(), base = 0)
+	except OSError:
+		size = 0
+
+	# Failure will raise an exception
+	f_size = open(f_output, "w")
+
+	# align to a page border
+	size += os.path.getsize(args.input) + 0xfff
+	size &= ~0xfff
+
+	f_size.write(f'0x{size:x}\n')
+
+if __name__ == "__main__":
+	main()

src/audio/eq_iir/llext/CMakeLists.txt

@@ -6,5 +6,4 @@ sof_llext_build("eq_iir"
 	SOURCES ../eq_iir.c
 		../eq_iir_ipc4.c
 		../eq_iir_generic.c
-	TEXT_ADDR 0xa06ea000
 )

src/audio/mixin_mixout/llext/CMakeLists.txt

@@ -7,5 +7,4 @@ sof_llext_build("mixin_mixout"
 		../mixin_mixout_hifi3.c
 		../mixin_mixout_hifi5.c
 		../mixin_mixout_generic.c
-	TEXT_ADDR 0xa06aa000
 )

src/audio/volume/llext/CMakeLists.txt

@@ -11,5 +11,4 @@ sof_llext_build("volume"
 		../volume_hifi4_with_peakvol.c
 		../volume.c
 		../volume_ipc4.c
-	TEXT_ADDR 0xa068a000
 )

src/library_manager/Kconfig

@@ -33,4 +33,13 @@ config LIBRARY_AUTH_SUPPORT
 	  could be used if enabled.
 	  If unsure say N.
 
+config LIBRARY_BASE_ADDRESS
+	hex "Base address for memory, dedicated to loadable modules"
+	default 0
+	help
+	  When initializing modules SOF will allocate memory for them and map
+	  it to a predefined per-module address. Those addresses are calculated
+	  automatically but the beginning of that area is platform-specific and
+	  should be set by this option.
+
 endmenu

src/samples/audio/smart_amp_test_llext/CMakeLists.txt

@@ -4,5 +4,4 @@
 # Hard-coded .text address to be moved to a common place
 sof_llext_build("smart_amp_test"
 	SOURCES ../smart_amp_test_ipc4.c
-	TEXT_ADDR 0xa06ca000
 )

zephyr/CMakeLists.txt

@@ -35,6 +35,13 @@ function(sof_append_relative_path_definitions target)
 	endforeach()
 endfunction()
 
+define_property(GLOBAL PROPERTY SOF_LLEXT_LAST_TARGET
+  BRIEF_DOCS "Last LLEXT target"
+  FULL_DOCS "\
+Building LLEXT targets must be serialized. This property contains the \
+previously added LLEXT module for the establishment of a dependency chain."
+)
+
 # Used by LLEXT modules to create a file with module UUIDs
 function(sof_llext_write_uuids module)
 	file(STRINGS ${CMAKE_CURRENT_LIST_DIR}/../${module}.toml uuids REGEX "^[ \t]*uuid *=")
@@ -51,7 +58,6 @@ endfunction()
 # Build an LLEXT module. Provice a module name, a list of sources and an address
 # of the .text section as arguments.
 function(sof_llext_build module)
-	set(single_args TEXT_ADDR)
 	set(multi_args SOURCES)
 	cmake_parse_arguments(PARSE_ARGV 1 SOF_LLEXT "${options}" "${single_args}" "${multi_args}")
 
@@ -88,13 +94,29 @@ function(sof_llext_build module)
 
 	get_target_property(proc_in_file ${module} lib_output)
 	get_target_property(proc_out_file ${module} pkg_input)
+	get_target_property(proc_pkg_file ${module} pkg_output)
+	set(size_file ${PROJECT_BINARY_DIR}/module_size)
+
+	get_property(last_target GLOBAL PROPERTY SOF_LLEXT_LAST_TARGET)
+	if(NOT "${last_target}" STREQUAL "")
+		add_dependencies(${module}_llext_proc ${last_target})
+	endif()
+	set_property(GLOBAL PROPERTY SOF_LLEXT_LAST_TARGET ${module})
+
 	add_llext_command(TARGET ${module}
 		POST_BUILD
-		COMMAND ${SOF_BASE}scripts/llext_link_helper.py
-			--text-addr="${SOF_LLEXT_TEXT_ADDR}" -f ${proc_in_file} ${CMAKE_C_COMPILER} --
+		COMMAND ${SOF_BASE}scripts/llext_link_helper.py -s ${size_file}
+			--text-addr=${CONFIG_LIBRARY_BASE_ADDRESS}
+			-f ${proc_in_file} ${CMAKE_C_COMPILER} --
 			-o ${proc_out_file} ${EXTRA_LINKER_PARAMS}
 	                $<TARGET_OBJECTS:${module}_llext_lib>
 	)
+
+	add_llext_command(TARGET ${module}
+		POST_PKG
+		COMMAND ${SOF_BASE}scripts/llext_offset_calc.py
+			-i ${proc_pkg_file} -s ${size_file}
+	)
 endfunction()
 
 # Initial SOF module will contain