Add MMIX support

2 files changed, 70 insertions, 0 deletions

diff --git a/ld/emulparams/elf64mmix.sh b/ld/emulparams/elf64mmix.sh
new file mode 100644
index 0000000..dc4b9e5
--- /dev/null
+++ b/ld/emulparams/elf64mmix.sh
@@ -0,0 +1,60 @@
+TEMPLATE_NAME=elf32
+GENERATE_SHLIB_SCRIPT=yes
+ELFSIZE=64
+SCRIPT_NAME=elf
+OUTPUT_FORMAT="elf64-mmix"
+ENTRY=_start.
+
+# Default to 0 as mmixal does.
+TEXT_START_ADDR='DEFINED (__.MMIX.start..text) ? __.MMIX.start..text : 0'
+# Don't add SIZEOF_HEADERS.
+# Don't set EMBEDDED, that would be misleading; it's not that kind of system.
+TEXT_BASE_ADDRESS=$TEXT_START_ADDR
+DATA_ADDR='DEFINED (__.MMIX.start..data) ? __.MMIX.start..data : 0x2000000000000000'
+
+# Setting this anywhere near the quite reasonable value of 0x10000
+# causes the binary to bloat to reach page alignment between segments.
+# Let's just have a 256-byte default page alignment.  Having some
+# alignment at all gives a warm feeling but not much more.
+MAXPAGESIZE=256
+ARCH=mmix
+MACHINE=
+COMPILE_IN=yes
+EXTRA_EM_FILE=mmixelf
+
+# The existence of a symbol __start (or _start) should overrule Main, so
+# it can be a user symbol without the associated mmixal magic.  We
+# also want to provide Main as a synonym for _start, if Main wasn't
+# defined but is referred to, and _start was defined.
+#
+# The reason we use a symbol "_start." as a mediator is to avoid
+# causing ld to force the type of _start to object rather than no
+# type, which confuses disassembly; we also make it alphanumerically
+# a successor of _start for similar reasons.  Perhaps it's a linker
+# bug that linker-defined symbols set the symbol-type.
+#
+# Note that we smuggle this into OTHER_TEXT_SECTIONS (at the end
+# of .text) rather than TEXT_START_SYMBOLS.  This is necessary, as
+# DEFINED wouldn't find the symbol if it was at the top; presumably
+# before the definition, if the definition is not in the first file.
+# FIXME: Arguably a linker bug.
+OTHER_TEXT_SECTIONS='
+ _start. = (DEFINED (_start) ? _start
+            : (DEFINED (Main) ? Main : (DEFINED (.text) ? .text : 0)));
+ PROVIDE (Main = DEFINED (Main) ? Main : (DEFINED (_start) ? _start : _start.));
+'
+
+OTHER_RELOCATING_SECTIONS='
+ .MMIX.reg_contents :
+ {
+   /* Note that this section always has a fixed VMA - that of its
+      first register * 8.  */
+   *(.MMIX.reg_contents);
+ }
+'
+
+# FIXME: Also bit by the PROVIDE bug?  If not, this could be
+# EXECUTABLE_SYMBOLS.
+# By default, put the high end of the stack where the register stack
+# begins.  They grow in opposite directions.  */
+OTHER_SECTIONS='PROVIDE (__Stack_start = 0x6000000000000000);'
diff --git a/ld/emulparams/mmo.sh b/ld/emulparams/mmo.sh
new file mode 100644
index 0000000..e0a8798
--- /dev/null
+++ b/ld/emulparams/mmo.sh
@@ -0,0 +1,10 @@
+SCRIPT_NAME=mmo
+TARGET_PAGE_SIZE=256
+
+# Default to 0 as mmixal does.
+TEXT_START_ADDR='DEFINED (__.MMIX.start..text) ? __.MMIX.start..text : 0'
+DATA_ADDR='DEFINED (__.MMIX.start..data) ? __.MMIX.start..data : 0x2000000000000000'
+OUTPUT_FORMAT=mmo
+ARCH=mmix
+COMPILE_IN=yes
+EXTRA_EM_FILE=mmo