diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | support/ld/common.inc | 32 | ||||
| -rw-r--r-- | support/make/build-rules.mk | 13 | ||||
| -rw-r--r-- | wirish/start.S | 6 | ||||
| -rw-r--r-- | wirish/start_c.c | 13 |
5 files changed, 44 insertions, 22 deletions
@@ -58,7 +58,7 @@ GLOBAL_CFLAGS := -Os -g3 -gdwarf-2 -mcpu=cortex-m3 -mthumb -march=armv7-m \ GLOBAL_CXXFLAGS := -fno-rtti -fno-exceptions -Wall $(TARGET_FLAGS) GLOBAL_ASFLAGS := -mcpu=cortex-m3 -march=armv7-m -mthumb \ -x assembler-with-cpp $(TARGET_FLAGS) -LDFLAGS = $(TARGET_LDFLAGS) -mcpu=cortex-m3 -mthumb \ +LDFLAGS = $(TARGET_LDFLAGS) $(TOOLCHAIN_LDFLAGS) -mcpu=cortex-m3 -mthumb \ -Xlinker --gc-sections \ -Xassembler --march=armv7-m -Wall # -Xlinker --print-gc-sections \ diff --git a/support/ld/common.inc b/support/ld/common.inc index f749b19..f5a0f5b 100644 --- a/support/ld/common.inc +++ b/support/ld/common.inc @@ -5,12 +5,20 @@ */ OUTPUT_FORMAT ("elf32-littlearm", "elf32-bigarm", "elf32-littlearm") -ENTRY(_start) /* - * Link against libgcc, libc, and libm + * Configure other libraries we want in the link. + * + * libgcc, libc, and libm are common across supported toolchains. + * However, some toolchains require additional archives which aren't + * present everywhere (e.g. ARM's gcc-arm-embedded releases). + * + * To hack around this, we let the build system specify additional + * archives by putting the right extra_libs.inc (in a directory under + * toolchains/) in our search path. */ GROUP(libgcc.a libc.a libm.a) +INCLUDE extra_libs.inc /* * These force the linker to search for vector table symbols. @@ -35,8 +43,9 @@ EXTERN(__msp_init) PROVIDE(__msp_init = ORIGIN(ram) + LENGTH(ram)); /* Reset vector and chip reset entry point */ -EXTERN(_start) -PROVIDE(__exc_reset = _start); +EXTERN(__start__) +ENTRY(__start__) +PROVIDE(__exc_reset = __start__); /* Heap boundaries, for libmaple */ EXTERN(_lm_heap_start); @@ -44,10 +53,9 @@ EXTERN(_lm_heap_end); SECTIONS { - /* TODO pull out rodata and stick into separate sections */ .text : { - _text = .; + __text_start__ = .; /* * STM32 vector table. Leave this here. Yes, really. */ @@ -107,7 +115,7 @@ SECTIONS .text.align : { . = ALIGN(8); - _etext = .; + __text_end__ = .; } > REGION_TEXT /* @@ -126,13 +134,13 @@ SECTIONS .data : { . = ALIGN(8); - _data = .; + __data_start__ = .; *(.got.plt) *(.got) *(.data .data.* .gnu.linkonce.d.*) . = ALIGN(8); - _edata = .; + __data_end__ = .; } > REGION_DATA AT> REGION_RODATA /* @@ -166,12 +174,12 @@ SECTIONS .bss : { . = ALIGN(8); - _bss = .; + __bss_start__ = .; *(.bss .bss.* .gnu.linkonce.b.*) *(COMMON) . = ALIGN (8); - _ebss = .; - _end = _ebss; + __bss_end__ = .; + _end = __bss_end__; } > REGION_BSS /* diff --git a/support/make/build-rules.mk b/support/make/build-rules.mk index 3d541ba..d180c89 100644 --- a/support/make/build-rules.mk +++ b/support/make/build-rules.mk @@ -22,6 +22,8 @@ ifndef V SILENT_OBJDUMP = @echo ' [OBJDUMP] ' $(OBJDUMP); endif +# Extra build configuration + BUILDDIRS := TGT_BIN := @@ -29,6 +31,17 @@ CFLAGS = $(GLOBAL_CFLAGS) $(TGT_CFLAGS) CXXFLAGS = $(GLOBAL_CXXFLAGS) $(TGT_CXXFLAGS) ASFLAGS = $(GLOBAL_ASFLAGS) $(TGT_ASFLAGS) +# Hacks to determine extra libraries we need to link against based on +# the toolchain. The default specifies no extra libraries, but it can +# be overridden. +LD_TOOLCHAIN_PATH := $(LDDIR)/toolchains/generic +ifneq ($(findstring ARM/embedded,$(shell $(CC) --version)),) +# GCC ARM Embedded, https://launchpad.net/gcc-arm-embedded/ +LD_TOOLCHAIN_PATH := $(LDDIR)/toolchains/gcc-arm-embedded +endif +# Add toolchain directory to LD search path +TOOLCHAIN_LDFLAGS := -L $(LD_TOOLCHAIN_PATH) + # General directory independent build rules, generate dependency information $(BUILD_PATH)/%.o: %.c $(SILENT_CC) $(CC) $(CFLAGS) -MMD -MP -MF $(@:%.o=%.d) -MT $@ -o $@ -c $< diff --git a/wirish/start.S b/wirish/start.S index 2488895..8b181aa 100644 --- a/wirish/start.S +++ b/wirish/start.S @@ -44,9 +44,9 @@ .code 16 .thumb_func - .globl _start - .type _start, %function -_start: + .globl __start__ + .type __start__, %function +__start__: .fnstart ldr r1,=__msp_init mov sp,r1 diff --git a/wirish/start_c.c b/wirish/start_c.c index 301565c..655fefb 100644 --- a/wirish/start_c.c +++ b/wirish/start_c.c @@ -50,8 +50,9 @@ extern int main(int, char**, char**); extern void exit(int) __attribute__((noreturn, weak)); -extern char _data, _edata; -extern char _bss, _ebss; +/* The linker must ensure that these are at least 4-byte aligned. */ +extern char __data_start__, __data_end__; +extern char __bss_start__, __bss_end__; struct rom_img_cfg { int *img_start; @@ -62,20 +63,20 @@ extern char _lm_rom_img_cfgp; void __attribute__((noreturn)) start_c(void) { struct rom_img_cfg *img_cfg = (struct rom_img_cfg*)&_lm_rom_img_cfgp; int *src = img_cfg->img_start; - int *dst = (int*)&_data; + int *dst = (int*)&__data_start__; int exit_code; /* Initialize .data, if necessary. */ if (src != dst) { - int *end = (int*)&_edata; + int *end = (int*)&__data_end__; while (dst < end) { *dst++ = *src++; } } /* Zero .bss. */ - dst = (int*)&_bss; - while (dst < (int*)&_ebss) { + dst = (int*)&__bss_start__; + while (dst < (int*)&__bss_end__) { *dst++ = 0; } |