Merge pull request #942 from zyp/external_software_packages

Allow external software packages to be linked into the BIOS

litex/soc/integration/builder.py

@@ -46,9 +46,6 @@ soc_software_packages = [
     "libliteeth",
     "liblitesdcard",
     "liblitesata",
-
-    # BIOS.
-    "bios"
 ]
 
 # Builder ------------------------------------------------------------------------------------------
@@ -105,16 +102,25 @@ class Builder:
         # Documentation
         self.generate_doc = generate_doc
 
-        # List software packages.
+        # List software packages and libraries.
         self.software_packages = []
+        self.software_libraries = []
+
         for name in soc_software_packages:
             self.add_software_package(name)
 
+            if name == "libbase":
+                name += "-nofloat"
+            self.add_software_library(name)
+
     def add_software_package(self, name, src_dir=None):
         if src_dir is None:
             src_dir = os.path.join(soc_directory, "software", name)
         self.software_packages.append((name, src_dir))
 
+    def add_software_library(self, name):
+        self.software_libraries.append(name)
+
     def _generate_includes(self):
         # Generate Include/Generated directories.
         _create_dir(self.include_dir)
@@ -123,12 +129,18 @@ class Builder:
         # Generate BIOS files when the SoC uses it.
         with_bios = self.soc.cpu_type not in [None, "zynq7000"]
         if with_bios:
+            self.add_software_package("bios")
 
             # Generate Variables to variables.mak.
             variables_contents = []
             def define(k, v):
                 variables_contents.append("{}={}".format(k, _makefile_escape(v)))
 
+            # Define packages and libraries.
+            define("PACKAGES", " ".join(name for name, src_dir in self.software_packages))
+            define("PACKAGE_DIRS", " ".join(src_dir for name, src_dir in self.software_packages))
+            define("LIBS", " ".join(self.software_libraries))
+
             # Define the CPU variables.
             for k, v in export.get_cpu_mak(self.soc.cpu, self.compile_software):
                 define(k, v)

litex/soc/software/bios/Makefile

@@ -54,28 +54,17 @@ endif
 
 bios.elf: $(BIOS_DIRECTORY)/linker.ld $(OBJECTS)
 
+vpath %.a $(PACKAGES:%=../%)
 
-%.elf: ../libbase/crt0.o \
-	../libcompiler_rt/libcompiler_rt.a \
-	../libbase/libbase-nofloat.a \
-	../liblitedram/liblitedram.a \
-	../libliteeth/libliteeth.a \
-	../liblitespi/liblitespi.a \
-	../libfatfs/libfatfs.a \
-	../liblitesdcard/liblitesdcard.a \
-	../liblitesata/liblitesata.a
+%.elf: ../libbase/crt0.o $(LIBS:%=%.a)
 	$(CC) $(LDFLAGS) -T $(BIOS_DIRECTORY)/linker.ld -N -o $@ \
 		../libbase/crt0.o \
 		$(OBJECTS) \
-		-L../libcompiler_rt \
-		-L../libbase \
-		-L../liblitedram \
-		-L../libliteeth \
-		-L../liblitespi \
-		-L../libfatfs \
-		-L../liblitesdcard \
-		-L../liblitesata \
-		-llitedram -lliteeth -llitespi -lfatfs -llitesdcard -llitesata -lbase-nofloat -lcompiler_rt
+		$(PACKAGES:%=-L../%) \
+		-Wl,--whole-archive \
+		-Wl,--gc-sections \
+		$(LIBS:lib%=-l%) \
+
 
 ifneq ($(OS),Windows_NT)
 	chmod -x $@

litex/soc/software/bios/helpers.c

@@ -10,6 +10,7 @@
 #include "readline.h"
 #include "helpers.h"
 #include "command.h"
+#include "init.h"
 
 extern unsigned int _ftext, _edata_rom;
 
@@ -126,3 +127,10 @@ struct command_struct *command_dispatcher(char *command, int nb_params, char **p
 
 	return NULL;
 }
+
+void init_dispatcher(void)
+{
+	for (const init_func* fp = __bios_init_start; fp != __bios_init_end; fp++) {
+		(*fp)();
+	}
+}

litex/soc/software/bios/helpers.h

@@ -5,5 +5,6 @@ void dump_bytes(unsigned int *ptr, int count, unsigned long addr);
 void crcbios(void);
 int get_param(char *buf, char **cmd, char **params);
 struct command_struct *command_dispatcher(char *command, int nb_params, char **params);
+void init_dispatcher(void);
 
 #endif

litex/soc/software/bios/init.h

@@ -0,0 +1,10 @@
+#pragma once
+
+typedef void (*init_func)(void);
+
+extern init_func const __bios_init_start[];
+extern init_func const __bios_init_end[];
+
+#define define_init_func(f)                                           \
+    const init_func __bios_init_##f __attribute__((__used__)) \
+    __attribute__((__section__(".bios_init"))) = f

litex/soc/software/bios/linker.ld

@@ -41,6 +41,13 @@ SECTIONS
 		PROVIDE_HIDDEN (__bios_cmd_end = .);
 	} > rom
 
+	.init :
+	{
+		PROVIDE_HIDDEN (__bios_init_start = .);
+		KEEP(*(.bios_init))
+		PROVIDE_HIDDEN (__bios_init_end = .);
+	} > rom
+
 	.data :
 	{
 		. = ALIGN(8);

litex/soc/software/bios/main.c

@@ -173,6 +173,8 @@ int main(int i, char **c)
 	video_framebuffer_dma_enable_write(1);
 #endif
 
+	init_dispatcher();
+
 	if(sdr_ok) {
 		printf("--============== \e[1mBoot\e[0m ==================--\n");
 		boot_sequence();