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authorMike Frysinger <vapier@gentoo.org>2008-10-11 21:40:26 -0400
committerMike Frysinger <vapier@gentoo.org>2009-01-28 13:26:14 -0500
commitb5eba3fafcccd1979380f12a256bd0e19be3d61e (patch)
tree703504cad609428edbd07d9d2ac64af56cf28916 /cpu/blackfin/start.S
parent95433f6d43ede6b40c1d900f3f704c839aa074f1 (diff)
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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 <vapier@gentoo.org>
Diffstat (limited to 'cpu/blackfin/start.S')
-rw-r--r--cpu/blackfin/start.S10
1 files changed, 7 insertions, 3 deletions
diff --git a/cpu/blackfin/start.S b/cpu/blackfin/start.S
index 8617c98..6c8def4 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;