X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=arch%2Farm%2Flib%2Fcrt0.S;h=4c3a94af572c58b4938885c0258b8ddd9ce13053;hb=8d8e13e129f20ef82a271094eb713d513e83adf4;hp=afd4f102dc87d4c0bcc5d9f2198f121d66f9f62f;hpb=5f757cdcc6efbefec09b8f964a234f84ff9fa7f6;p=u-boot

diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
index afd4f102dc..4c3a94af57 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -25,7 +25,8 @@
  *    the GD ('global data') structure, both located in some readily
  *    available RAM (SRAM, locked cache...). In this context, VARIABLE
  *    global data, initialized or not (BSS), are UNAVAILABLE; only
- *    CONSTANT initialized data are available.
+ *    CONSTANT initialized data are available. GD should be zeroed
+ *    before board_init_f() is called.
  *
  * 2. Call board_init_f(). This function prepares the hardware for
  *    execution from system RAM (DRAM, DDR...) As system RAM may not
@@ -34,24 +35,29 @@
  *    data include the relocation destination, the future stack, and
  *    the future GD location.
  *
- * (the following applies only to non-SPL builds)
- *
  * 3. Set up intermediate environment where the stack and GD are the
  *    ones allocated by board_init_f() in system RAM, but BSS and
  *    initialized non-const data are still not available.
  *
- * 4. Call relocate_code(). This function relocates U-Boot from its
- *    current location into the relocation destination computed by
- *    board_init_f().
+ * 4a.For U-Boot proper (not SPL), call relocate_code(). This function
+ *    relocates U-Boot from its current location into the relocation
+ *    destination computed by board_init_f().
+ *
+ * 4b.For SPL, board_init_f() just returns (to crt0). There is no
+ *    code relocation in SPL.
  *
  * 5. Set up final environment for calling board_init_r(). This
  *    environment has BSS (initialized to 0), initialized non-const
  *    data (initialized to their intended value), and stack in system
- *    RAM. GD has retained values set by board_init_f(). Some CPUs
- *    have some work left to do at this point regarding memory, so
- *    call c_runtime_cpu_setup.
+ *    RAM (for SPL moving the stack and GD into RAM is optional - see
+ *    CONFIG_SPL_STACK_R). GD has retained values set by board_init_f().
+ *
+ * 6. For U-Boot proper (not SPL), some CPUs have some work left to do
+ *    at this point regarding memory, so call c_runtime_cpu_setup.
+ *
+ * 7. Branch to board_init_r().
  *
- * 6. Branch to board_init_r().
+ * For more information see 'Board Initialisation Flow in README.
  */
 
 /*