configure: Add option to set physical memory start address

For systems where physical memory is mapped to a start address
different from 0x80000000, allow the default to be overridden
using the --with-mem-start argument to the configure script.

Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>

Makefile.in

@@ -278,7 +278,7 @@ $$($(2)_install_prog_objs) : %.o : %.c
 	$(COMPILE) -c $$<
 
 $$($(2)_install_prog_exes) : % : %.o $$($(2)_prog_libnames)
-	$(LINK) -o $$@ $$< $$($(2)_prog_libarg) $(LIBS) -T $(src_dir)/$(2)/$(2).lds
+	$(LINK) -o $$@ $$< $$($(2)_prog_libarg) $(LIBS) -Wl,--defsym=MEM_START=@MEM_START@,-T,$(src_dir)/$(2)/$(2).lds
 
 $(2)_c_deps += $$($(2)_install_prog_deps)
 $(2)_junk += \

bbl/bbl.lds

@@ -12,7 +12,7 @@ SECTIONS
   /*--------------------------------------------------------------------*/
 
   /* Begining of code and text segment */
-  . = 0x80000000;
+  . = MEM_START;
   _ftext = .;
 
   .text :

configure

@@ -593,6 +593,7 @@ subprojects
 BBL_LOGO_FILE
 BBL_PAYLOAD
 BBL_ENABLE_LOGO
+MEM_START
 WITH_ARCH
 RISCV
 EGREP
@@ -672,6 +673,7 @@ enable_option_checking
 enable_stow
 with_arch
 enable_print_device_tree
+with_mem_start
 enable_optional_subprojects
 enable_vm
 enable_logo
@@ -1333,6 +1335,7 @@ Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
   --with-arch             Set the RISC-V architecture
+  --with-mem-start        Set physical memory start address
   --with-payload          Set ELF payload for bbl
   --with-logo             Specify a better logo
 
@@ -4105,6 +4108,21 @@ LIBS="-lgcc"
 
 
 
+
+# Check whether --with-mem-start was given.
+if test "${with_mem_start+set}" = set; then :
+  withval=$with_mem_start;
+   MEM_START=$with_mem_start
+
+
+else
+
+   MEM_START=0x80000000
+
+
+fi
+
+
 #-------------------------------------------------------------------------
 # MCPPBS subproject list
 #-------------------------------------------------------------------------

configure.ac

@@ -97,6 +97,13 @@ AC_SUBST([LIBS], ["-lgcc"])
 AC_SUBST(WITH_ARCH)
 AC_SUBST(host_alias)
 
+AC_ARG_WITH([mem-start], AS_HELP_STRING([--with-mem-start], [Set physical memory start address]),
+  [
+   AC_SUBST([MEM_START], $with_mem_start, [Physical memory start address])
+  ], [
+   AC_SUBST([MEM_START], [0x80000000], [Physical memory start address])
+  ])
+
 #-------------------------------------------------------------------------
 # MCPPBS subproject list
 #-------------------------------------------------------------------------

pk/pk.lds

@@ -12,7 +12,7 @@ SECTIONS
   /*--------------------------------------------------------------------*/
 
   /* Begining of code and text segment */
-  . = 0x80000000;
+  . = MEM_START;
   _ftext = .;
 
   .text :