Remove CS3-style initialization.

Remove libcs3-related bits from support/ld. Break them out into
libmaple proper and Wirish as appropriate: vector table definition and
ISR declarations go into libmaple proper, and startup code goes into
Wirish. Vector table symbols are included into common.inc from an
STM32 family-specific directory under support/ld/stm32.

This is a combination of 5 commits. Individual commit messages follow:

libcs3_stm32_src: Don't depend on cs3.h.

So we can use the existing toolchain.

Move ISR decls/vector table into libmaple proper.

This allows us to configure the vector table on a per-family basis.

- Move
        support/ld/libcs3_stm32_src/stm32_isrs.S
                                    stm32_vector_table.S
  to
        libmaple/stm32f1/isrs_performance.S
                         vector_table_performance.S,
  respectively.

  The directory libmaple/stm32f1/ is intended to hold all
  STM32F1-specific code within libmaple. Obviously, there's a lot of
  work to do before this becomes true.

- support/ld/libcs3_stm32_src/Makefile: Don't try to compile
  stm32_isrs.S and stm32_vector_table.S anymore.

- Add libmaple/stm32f1/rules.mk to include these new files in the
  standard libmaple build.

- support/make/target-config.mk: Add LIBMAPLE_MODULE_FAMILY, which
  selects a directory to use as a family-specific libmaple
  submodule.

- Makefile: Add LIBMAPLE_MODULE_FAMILY to LIBMAPLE_MODULES.

Remove support/ld/libcs3_stm32_src and derived object files.

From support/ld/libcs3_stm32_src, move start.S and start_c.c into
Wirish. Modify wirish/rules.mk accordingly.

Delete support/ld/libcs3_stm32_*_density.a. These are no longer
necessary, as the relevant objects are included in the standard Wirish
build. Remove the GROUP statements from the board linker scripts
accordingly.

Remove SEARCH_DIR(.) from common.inc; it's no longer necessary. Also
fix up some comments that are now out of date.

wirish/start_c.c: Don't use CS3-style memory initialization.

Switch memory initialization to a simpler style of initializing .data
if necessary, then zeroing .bss. Initializing .data is only necessary
during Flash builds, since during RAM builds, LOADADDR(.data) ==
ADDR(.data).

This makes libmaple completely incompatible with the CS3 startup
sequence. Subsequent commits will clean up the namespace to reflect
that fact.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

24 files changed, 74 insertions, 141 deletions

diff --git a/Makefile b/Makefile
index 11a3ccc..45b34da 100644
--- a/Makefile
+++ b/Makefile
@@ -73,6 +73,7 @@ ifeq ($(LIBMAPLE_MODULES),)
 else
 	LIBMAPLE_MODULES += $(SRCROOT)/libmaple
 endif
+LIBMAPLE_MODULES += $(LIBMAPLE_MODULE_FAMILY) # family submodule in libmaple
 LIBMAPLE_MODULES += $(SRCROOT)/wirish
 # Official libraries:
 LIBMAPLE_MODULES += $(SRCROOT)/libraries/Servo
diff --git a/support/ld/libcs3_stm32_src/stm32_isrs.S b/libmaple/stm32f1/isrs_performance.S
index be102e7..be102e7 100644
--- a/support/ld/libcs3_stm32_src/stm32_isrs.S
+++ b/libmaple/stm32f1/isrs_performance.S
diff --git a/libmaple/stm32f1/rules.mk b/libmaple/stm32f1/rules.mk
new file mode 100644
index 0000000..5cadefd
--- /dev/null
+++ b/libmaple/stm32f1/rules.mk
@@ -0,0 +1,23 @@
+# Standard things
+sp              := $(sp).x
+dirstack_$(sp)  := $(d)
+d               := $(dir)
+BUILDDIRS       += $(BUILD_PATH)/$(d)
+
+# Local rules and targets
+sSRCS_$(d) := isrs_performance.S            \
+              vector_table_performance.S
+
+sFILES_$(d) := $(sSRCS_$(d):%=$(d)/%)
+
+OBJS_$(d) := $(sFILES_$(d):%.S=$(BUILD_PATH)/%.o)
+DEPS_$(d) := $(OBJS_$(d):%.o=%.d)
+
+$(OBJS_$(d)): TGT_ASFLAGS :=
+
+TGT_BIN += $(OBJS_$(d))
+
+# Standard things
+-include        $(DEPS_$(d))
+d               := $(dirstack_$(sp))
+sp              := $(basename $(sp))
diff --git a/support/ld/libcs3_stm32_src/stm32_vector_table.S b/libmaple/stm32f1/vector_table_performance.S
index 7067d95..7067d95 100644
--- a/support/ld/libcs3_stm32_src/stm32_vector_table.S
+++ b/libmaple/stm32f1/vector_table_performance.S
diff --git a/support/ld/common.inc b/support/ld/common.inc
index c6fa13a..0d1f4ed 100644
--- a/support/ld/common.inc
+++ b/support/ld/common.inc
@@ -6,7 +6,6 @@
 
 OUTPUT_FORMAT ("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
 ENTRY(_start)
-SEARCH_DIR(.)
 
 /*
  * Link against libgcc, libc, and libm
@@ -22,10 +21,10 @@ GROUP(libgcc.a libc.a libm.a)
  */
 INCLUDE vector_symbols.inc
 
-/* STM32 vector table. See stm32_vector_table.S  */
+/* STM32 vector table. */
 EXTERN(__cs3_stm32_vector_table)
 
-/* libcs3 C start function. See cs3.h */
+/* libcs3 C start function. */
 EXTERN(__cs3_start_c)
 
 /* main entry point */
@@ -33,9 +32,9 @@ EXTERN(main)
 
 /* Initial stack pointer value. */
 EXTERN(__cs3_stack)
-PROVIDE(__cs3_stack = __cs3_region_start_ram + LENGTH(ram));
+PROVIDE(__cs3_stack = ORIGIN(ram) + LENGTH(ram));
 
-/* Reset vector and chip reset entry point. See start.S */
+/* Reset vector and chip reset entry point */
 EXTERN(_start)
 PROVIDE(__cs3_reset = _start);
 
@@ -48,7 +47,7 @@ SECTIONS
     /* TODO pull out rodata and stick into separate sections  */
     .text :
       {
-        __text_start = .;
+        _text = .;
         /*
          * STM32 vector table.  Leave this here.  Yes, really.
          */
@@ -100,17 +99,6 @@ SECTIONS
         KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
         KEEP (*(SORT(.dtors.*)))
         KEEP (*crtend.o(.dtors))
-
-        /*
-         * struct __cs3_region used during __cs3_start_c
-         */
-        . = ALIGN(4);
-        __cs3_regions = .;
-        LONG (0)                          /* flags */
-        LONG (__cs3_region_init_ram)      /* initial contents */
-        LONG (__cs3_region_start_ram)     /* start address */
-        LONG (__cs3_region_init_size_ram) /* size of initial data */
-        LONG (__cs3_region_zero_size_ram) /* additional size to be zeroed */
       } > REGION_TEXT
 
     /*
@@ -119,6 +107,11 @@ SECTIONS
     .rodata :
       {
         *(.rodata .rodata.* .gnu.linkonce.r.*)
+
+        /* ROM image configuration; for C startup */
+        . = ALIGN(4);
+        _lm_rom_img_cfgp = .;
+        LONG(LOADADDR(.data));
       } > REGION_RODATA
 
     /*
@@ -153,7 +146,8 @@ SECTIONS
      */
     .data :
       {
-        __cs3_region_start_ram = DEFINED(_FLASH_BUILD) ? . : __text_start;
+        . = ALIGN(8);
+        _data = .;
 
         *(.got.plt) *(.got)
         *(.data .data.* .gnu.linkonce.d.*)
@@ -178,26 +172,16 @@ SECTIONS
      */
     .bss :
       {
+        . = ALIGN(8);
+        _bss = .;
         *(.bss .bss.* .gnu.linkonce.b.*)
         *(COMMON)
         . = ALIGN (8);
-        _end = .;
+        _ebss = .;
+        _end = _ebss;
       } > REGION_BSS AT> REGION_TEXT
 
     /*
-     * Constants needed for the pieces of CS3 we use during
-     * board startup; see libcs3_stm32_src/.
-     */
-    __cs3_region_init_ram = (DEFINED(_FLASH_BUILD) ?
-                             LOADADDR(.data) :
-                             LOADADDR(.text));
-    __cs3_region_init_size_ram = (DEFINED(_FLASH_BUILD) ?
-                                  _edata - ADDR(.data) :
-                                  _edata - ADDR(.text));
-    __cs3_region_zero_size_ram = _end - _edata;
-    __cs3_region_num = 1;
-
-    /*
      * Debugging sections
      */
     .stab 0 (NOLOAD) : { *(.stab) }
diff --git a/support/ld/libcs3_stm32_high_density.a b/support/ld/libcs3_stm32_high_density.a
deleted file mode 100644
index b6650ca..0000000
--- a/support/ld/libcs3_stm32_high_density.a
+++ /dev/null
diff --git a/support/ld/libcs3_stm32_med_density.a b/support/ld/libcs3_stm32_med_density.a
deleted file mode 100644
index e4660e3..0000000
--- a/support/ld/libcs3_stm32_med_density.a
+++ /dev/null
diff --git a/support/ld/libcs3_stm32_src/Makefile b/support/ld/libcs3_stm32_src/Makefile
deleted file mode 100644
index 834cdad..0000000
--- a/support/ld/libcs3_stm32_src/Makefile
+++ /dev/null
@@ -1,35 +0,0 @@
-# setup environment
-
-TARGET_ARCH = -mcpu=cortex-m3 -mthumb
-
-CC = arm-none-eabi-gcc
-CFLAGS =
-
-AS = $(CC) -x assembler-with-cpp -c $(TARGET_ARCH)
-ASFLAGS =
-
-AR = arm-none-eabi-ar
-ARFLAGS = cr
-
-LIB_OBJS = stm32_vector_table.o stm32_isrs.o start.o start_c.o
-
-help:
-	@echo "Targets:"
-	@echo "\t medium-density: Target medium density chips (e.g. Maple)"
-	@echo "\t high-density: Target high density chips (e.g. Maple-native)"
-
-.PHONY: help medium high
-
-medium-density: $(LIB_OBJS)
-	$(AR) $(ARFLAGS) libcs3_stm32_med_density.a $(LIB_OBJS)
-	rm -f $(LIB_OBJS)
-
-high-density: CFLAGS := -DSTM32_HIGH_DENSITY
-high-density: $(LIB_OBJS)
-	$(AR) $(ARFLAGS) libcs3_stm32_high_density.a $(LIB_OBJS)
-	rm -f $(LIB_OBJS)
-
-# clean
-.PHONY: clean
-clean:
-	-rm -f $(LIB_OBJS) *.a
diff --git a/support/ld/maple/flash.ld b/support/ld/maple/flash.ld
index 8a179f7..190c187 100644
--- a/support/ld/maple/flash.ld
+++ b/support/ld/maple/flash.ld
@@ -11,11 +11,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 108K
 }
 
-/*
- * Use medium density device vector table
- */
-GROUP(libcs3_stm32_med_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple/jtag.ld b/support/ld/maple/jtag.ld
index 365068f..c090988 100644
--- a/support/ld/maple/jtag.ld
+++ b/support/ld/maple/jtag.ld
@@ -12,11 +12,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08000000, LENGTH = 128K
 }
 
-/*
- * Use medium density device vector table
- */
-GROUP(libcs3_stm32_med_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple/ram.ld b/support/ld/maple/ram.ld
index 6f237c3..a5ef621 100644
--- a/support/ld/maple/ram.ld
+++ b/support/ld/maple/ram.ld
@@ -11,11 +11,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 0K
 }
 
-/*
- * Use medium density device vector table
- */
-GROUP(libcs3_stm32_med_density.a)
-
 REGION_ALIAS("REGION_TEXT", ram);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_RET6/flash.ld b/support/ld/maple_RET6/flash.ld
index 4cf9c4b..8b529f8 100644
--- a/support/ld/maple_RET6/flash.ld
+++ b/support/ld/maple_RET6/flash.ld
@@ -9,8 +9,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 492K
 }
 
-GROUP(libcs3_stm32_high_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_RET6/jtag.ld b/support/ld/maple_RET6/jtag.ld
index 6055dfb..4ac9d76 100644
--- a/support/ld/maple_RET6/jtag.ld
+++ b/support/ld/maple_RET6/jtag.ld
@@ -9,8 +9,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08000000, LENGTH = 512K
 }
 
-GROUP(libcs3_stm32_high_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_RET6/ram.ld b/support/ld/maple_RET6/ram.ld
index a4c273b..65c3a2c 100644
--- a/support/ld/maple_RET6/ram.ld
+++ b/support/ld/maple_RET6/ram.ld
@@ -9,8 +9,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 0K
 }
 
-GROUP(libcs3_stm32_high_density.a)
-
 REGION_ALIAS("REGION_TEXT", ram);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_mini/flash.ld b/support/ld/maple_mini/flash.ld
index ab03207..52d01dc 100644
--- a/support/ld/maple_mini/flash.ld
+++ b/support/ld/maple_mini/flash.ld
@@ -11,11 +11,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 108K
 }
 
-/*
- * Use medium density device vector table
- */
-GROUP(libcs3_stm32_med_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_mini/jtag.ld b/support/ld/maple_mini/jtag.ld
index 2f9cf31..28e204f 100644
--- a/support/ld/maple_mini/jtag.ld
+++ b/support/ld/maple_mini/jtag.ld
@@ -12,11 +12,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08000000, LENGTH = 128K
 }
 
-/*
- * Use medium density device vector table
- */
-GROUP(libcs3_stm32_med_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_mini/ram.ld b/support/ld/maple_mini/ram.ld
index 0ba0252..5b0111b 100644
--- a/support/ld/maple_mini/ram.ld
+++ b/support/ld/maple_mini/ram.ld
@@ -11,11 +11,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 0K
 }
 
-/*
- * Use medium density device vector table
- */
-GROUP(libcs3_stm32_med_density.a)
-
 REGION_ALIAS("REGION_TEXT", ram);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_native/flash.ld b/support/ld/maple_native/flash.ld
index b6e10f8..aac5325 100644
--- a/support/ld/maple_native/flash.ld
+++ b/support/ld/maple_native/flash.ld
@@ -8,11 +8,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 492K
 }
 
-/*
- * Use high density device vector table
- */
-GROUP(libcs3_stm32_high_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_native/jtag.ld b/support/ld/maple_native/jtag.ld
index 9af2a11..412348e 100644
--- a/support/ld/maple_native/jtag.ld
+++ b/support/ld/maple_native/jtag.ld
@@ -9,11 +9,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08000000, LENGTH = 512K
 }
 
-/*
- * Use high density device vector table
- */
-GROUP(libcs3_stm32_high_density.a)
-
 REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/ld/maple_native/ram.ld b/support/ld/maple_native/ram.ld
index 7264316..eeec761 100644
--- a/support/ld/maple_native/ram.ld
+++ b/support/ld/maple_native/ram.ld
@@ -8,11 +8,6 @@ MEMORY
   rom (rx)  : ORIGIN = 0x08005000, LENGTH = 0K
 }
 
-/*
- * Use high density device vector table
- */
-GROUP(libcs3_stm32_high_density.a)
-
 REGION_ALIAS("REGION_TEXT", ram);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
diff --git a/support/make/target-config.mk b/support/make/target-config.mk
index f935cad..592e808 100644
--- a/support/make/target-config.mk
+++ b/support/make/target-config.mk
@@ -52,11 +52,12 @@ endif
 
 # STM32 family-specific configuration values.
 
-# NB: this only works for STM32F1 performance line chips, but those
+# NB: these only work for STM32F1 performance line chips, but those
 # are the only ones we support at this time.  If you add support for
 # STM32F1 connectivity line MCUs or other STM32 families, this section
 # will need to change.
 LD_FAMILY_PATH := $(LDDIR)/stm32/f1/performance
+LIBMAPLE_MODULE_FAMILY := $(LIBMAPLE_PATH)/stm32f1
 
 # Memory target-specific configuration values
 
diff --git a/wirish/rules.mk b/wirish/rules.mk
index 6aa0904..1bf6245 100644
--- a/wirish/rules.mk
+++ b/wirish/rules.mk
@@ -12,8 +12,9 @@ WIRISH_INCLUDES := -I$(d) -I$(d)/comm -I$(d)/boards
 CFLAGS_$(d) := $(WIRISH_INCLUDES) $(LIBMAPLE_INCLUDES)
 
 # Local rules and targets
-cSRCS_$(d) :=  
 
+sSRCS_$(d) := start.S
+cSRCS_$(d) := start_c.c
 cppSRCS_$(d) := wirish_math.cpp		 \
                 Print.cpp		 \
 		boards.cpp               \
@@ -34,10 +35,12 @@ cppSRCS_$(d) := wirish_math.cpp		 \
 		ext_interrupts.cpp	 \
 		wirish_digital.cpp
 
+sFILES_$(d)   := $(sSRCS_$(d):%=$(d)/%)
 cFILES_$(d)   := $(cSRCS_$(d):%=$(d)/%)
 cppFILES_$(d) := $(cppSRCS_$(d):%=$(d)/%)
 
-OBJS_$(d)     := $(cFILES_$(d):%.c=$(BUILD_PATH)/%.o) \
+OBJS_$(d)     := $(sFILES_$(d):%.S=$(BUILD_PATH)/%.o) \
+                 $(cFILES_$(d):%.c=$(BUILD_PATH)/%.o) \
                  $(cppFILES_$(d):%.cpp=$(BUILD_PATH)/%.o)
 DEPS_$(d)     := $(OBJS_$(d):%.o=%.d)
 
diff --git a/support/ld/libcs3_stm32_src/start.S b/wirish/start.S
index 4d1d405..4d1d405 100644
--- a/support/ld/libcs3_stm32_src/start.S
+++ b/wirish/start.S
diff --git a/support/ld/libcs3_stm32_src/start_c.c b/wirish/start_c.c
index 2ab0212..cb96fc5 100644
--- a/support/ld/libcs3_stm32_src/start_c.c
+++ b/wirish/start_c.c
@@ -13,7 +13,7 @@
  * they apply.
  */
 
-#include "cs3.h"
+#include <stddef.h>
 
 extern void __libc_init_array (void);
 
@@ -21,30 +21,37 @@ extern int main (int, char **, char **);
 
 extern void exit (int) __attribute__ ((noreturn, weak));
 
-void  __attribute ((noreturn))
+extern char _data, _edata;
+extern char _bss, _ebss;
+
+struct rom_img_cfg {
+  long long *img_start;
+};
+
+extern char _lm_rom_img_cfgp;
+
+void  __attribute__ ((noreturn))
 __cs3_start_c (void)
 {
-  unsigned regions = __cs3_region_num;
-  const struct __cs3_region *rptr = __cs3_regions;
+  struct rom_img_cfg *img_cfg = (struct rom_img_cfg*)&_lm_rom_img_cfgp;
+  long long *src;
+  long long *dst;
   int exit_code;
 
-  /* Initialize memory */
-  for (regions = __cs3_region_num, rptr = __cs3_regions; regions--; rptr++)
-    {
-      long long *src = (long long *)rptr->init;
-      long long *dst = (long long *)rptr->data;
-      unsigned limit = rptr->init_size;
-      unsigned count;
-
-      if (src != dst)
-	for (count = 0; count != limit; count += sizeof (long long))
-	  *dst++ = *src++;
-      else
-	dst = (long long *)((char *)dst + limit);
-      limit = rptr->zero_size;
-      for (count = 0; count != limit; count += sizeof (long long))
-	*dst++ = 0;
+  /* Initialize .data, if necessary. */
+  src = img_cfg->img_start;
+  dst = (long long*)&_data;
+  if (src != dst) {
+    while (dst < (long long*)&_edata) {
+      *dst++ = *src++;
     }
+  }
+
+  /* Zero .bss. */
+  dst = (long long*)&_bss;
+  while (dst < (long long*)&_ebss) {
+    *dst++ = 0;
+  }
 
   /* Run initializers.  */
   __libc_init_array ();