Merge branch 'sun9i-a80-spl' of http://git.denx.de/u-boot-sunxi

[u-boot] / arch / arm / lib / crt0_64.S

diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
index 77563967e517902863a530967f4c2ea02e891305..91b19e00da22cd12a68991cc40680de0736651ca 100644 (file)
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -27,7 +27,8 @@
  *    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
@@ -36,24 +37,31 @@
  *    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().
+ *
+ * TODO: For SPL, implement stack relocation on AArch64.
+ *
+ * 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.
  *
- * 6. Branch to board_init_r().
+ * 7. Branch to board_init_r().
+ *
+ * For more information see 'Board Initialisation Flow in README.
  */
 
 ENTRY(_main)
@@ -61,13 +69,23 @@ ENTRY(_main)
 /*
  * Set up initial C runtime environment and call board_init_f(0).
  */
+#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)
+       ldr     x0, =(CONFIG_SPL_STACK)
+#else
        ldr     x0, =(CONFIG_SYS_INIT_SP_ADDR)
-       sub     x0, x0, #GD_SIZE        /* allocate one GD above SP */
+#endif
        bic     sp, x0, #0xf    /* 16-byte alignment for ABI compliance */
-       mov     x18, sp                 /* GD is above SP */
+       mov     x0, sp
+       bl      board_init_f_alloc_reserve
+       mov     sp, x0
+       /* set up gd here, outside any C code */
+       mov     x18, x0
+       bl      board_init_f_init_reserve
+
        mov     x0, #0
        bl      board_init_f
 
+#if !defined(CONFIG_SPL_BUILD)
 /*
  * Set up intermediate environment (new sp and gd) and call
  * relocate_code(addr_moni). Trick here is that we'll return
@@ -90,6 +108,9 @@ relocation_return:
  * Set up final (full) environment
  */
        bl      c_runtime_cpu_setup             /* still call old routine */
+#endif /* !CONFIG_SPL_BUILD */
+
+/* TODO: For SPL, call spl_relocate_stack_gd() to alloc stack relocation */
 
 /*
  * Clear BSS section