ARM i.MX: Add i.MX specific entry point for barebox

Additionally to the generic entry point the i.MX specific ones
calculate the SDRAM size automatically so the boards do not have
to care.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm/cpu/start-pbl.c b/arch/arm/cpu/start-pbl.c
index da62111bfb..11ab02523e 100644
--- a/arch/arm/cpu/start-pbl.c
+++ b/arch/arm/cpu/start-pbl.c
@@ -190,6 +190,18 @@ void __naked __noreturn board_init_lowlevel_return(void)
  * full SDRAM. The currently running binary can be inside or outside of this
  * region. TEXT_BASE can be inside or outside of this region. boarddata will
  * be preserved and can be accessed later with barebox_arm_boarddata().
+ *
+ * -> membase + memsize
+ *   ARM_RESERVE_MEM_SIZE    - reserved for board usage. Will not be touched
+ *                             by barebox
+ *   STACK_SIZE              - stack
+ *   16KiB, aligned to 16KiB - First level page table if early MMU support
+ *                             is enabled
+ *   128KiB                  - early memory space
+ * -> maximum end of barebox binary
+ *
+ * Usually a TEXT_BASE of 1MiB below your lowest possible end of memory should
+ * be fine.
  */
 void __naked __noreturn barebox_arm_entry(uint32_t membase, uint32_t memsize,
 		uint32_t boarddata)