Hi all, I am new to u-boot. But I am ramping up pretty fast. My primary issue is understanding the Makefile syntax. Is there a good tutorial somewhere that explains how u-boot uses the Makefiles and their syntax?
For example, I'm having problems understanding what this means in a Makefile:
COBJS-$(CONFIG_HAS_DATAFLASH) += at45.o COBJS-$(CONFIG_FLASH_CFI_DRIVER) += cfi_flash.o COBJS-$(CONFIG_HAS_DATAFLASH) += dataflash.o COBJS-$(CONFIG_FLASH_CFI_LEGACY) += jedec_flash.o COBJS-$(CONFIG_MW_EEPROM) += mw_eeprom.o
COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) OBJS := $(addprefix $(obj),$(COBJS))
This is from drivers/mtd/Makefile.
How does COBJS get initially defined upon entry into the Makefile?
Does at45.o get added to the list of objects to be built only if the CONFIG_HAS_DATAFLASH flag is set?
What does the "-" sign mean before the "$" ?
What does this mean? COBJS := $(COBJS-y)
I'm sorry for the "dumb" questions. Any help with the understanding of Makefiles would be greatly appreciated.
Thanks in advance, Steve