From b5eba3fafcccd1979380f12a256bd0e19be3d61e Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Sat, 11 Oct 2008 21:40:26 -0400 Subject: Blackfin: clarify relocation comment during init People often ask questions about the init process and when things go from flash to relocated base, so clarify the comments a bit. Signed-off-by: Mike Frysinger --- cpu/blackfin/start.S | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'cpu/blackfin') diff --git a/cpu/blackfin/start.S b/cpu/blackfin/start.S index 8617c9852e..6c8def4816 100644 --- a/cpu/blackfin/start.S +++ b/cpu/blackfin/start.S @@ -125,9 +125,11 @@ ENTRY(_start) */ r6 = 1 (x); - /* Relocate from wherever are (FLASH/RAM/etc...) to the hardcoded + /* Relocate from wherever we are (FLASH/RAM/etc...) to the hardcoded * monitor location in the end of RAM. We know that memcpy() only - * uses registers, so it is safe to call here. + * uses registers, so it is safe to call here. Note that this only + * copies to external memory ... we do not start executing out of + * it yet (see "lower to 15" below). */ serial_early_puts("Relocate"); call _get_pc; @@ -172,7 +174,9 @@ ENTRY(_start) * setting the 15 handler to ".Lenable_nested", raising the 15 * interrupt, and then returning from the highest interrupt * level to the dummy "jump" until the interrupt controller - * services the pending 15 interrupt. + * services the pending 15 interrupt. If executing out of + * flash, these steps also changes the code flow from flash + * to external memory. */ serial_early_puts("Lower to 15"); r0 = r7; -- cgit v1.2.1