Rick,
Should we put all the init code into cpu/at91rm9200/{start.S} and use CONFIG_ and CFG_?
I'd put it all in start.S and not define any CONFIG for it. But one thing you might check is if it will start up when the clocks are already configured. In other words, make sure your new u-boot can be started from an already running u-boot. This is necessary because the AT91RM9200 can be started from SPI DataFlash (or EEPROM) which requires a preloader. The preloader sets up clocks for SDRAM, etc and then launches u-boot.
I have a sperate entry in a Makefile for compiling u-boot up to run in ram so that I can fire a new u-boot while inside u-boot:
ram: cd u-boot-0.4.0; \ echo TEXT_BASE = 0x21fa0000 > board/at91rm9200dk/config.mk; \ make at91rm9200dk_config; \ make; \ cp -f u-boot.bin /tftpboot
And then from u-boot I do:
tftp 21fa0000 u-boot.bin # load u-boot go 21fa0000 # run u-boot
Ok. I see. So you're building a special version of U-Boot for this anyway (using make ram). Right?
I've seen: /* * we do sys-critical inits only at reboot, * not when booting from ram! */ #ifdef CONFIG_INIT_CRITICAL bl cpu_init_crit #endif
in cpu/arm920t/start.S and
#define CONFIG_INIT_CRITICAL /* undef for developing */
in some board specific header file.
So. Would you agree on a mechanism like that?
You could still do something like that in your Makefile:
ram: cd u-boot-0.4.0; \ echo TEXT_BASE = 0x21fa0000 > board/at91rm9200dk/config.mk; \ make at91rm9200dk_config; \
echo "#undef CONFIG_INIT_CRITICAL" >> include/config.h; \
make; \ cp -f u-boot.bin /tftpboot
I think this would better better than trying to autodetect if the system was already configured. Ok?
Steven