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authorAlbert ARIBAUD <albert.u.boot@aribaud.net>2015-11-25 17:56:32 +0100
committerTom Rini <trini@konsulko.com>2016-01-13 21:05:17 -0500
commitecc306639e83c9019a5093b77a48685ea40eedc2 (patch)
tree7785c9d7358ccd22ddabe52489aae8a8c7035ffe /include/common.h
parent20d08f59fa7cdde0da1eb7aca7915c91dbdeaf51 (diff)
Fix board init code to respect the C runtime environment
board_init_f_mem() alters the C runtime environment's stack it is actually already using. This is not a valid behaviour within a C runtime environment. Split board_init_f_mem into C functions which do not alter their own stack and always behave properly with respect to their C runtime environment. Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net> Acked-by: Thomas Chou <thomas@wytron.com.tw>
Diffstat (limited to 'include/common.h')
-rw-r--r--include/common.h34
1 files changed, 14 insertions, 20 deletions
diff --git a/include/common.h b/include/common.h
index 75c78d5ac2f..7bed0cc0d12 100644
--- a/include/common.h
+++ b/include/common.h
@@ -224,32 +224,26 @@ void board_init_f(ulong);
void board_init_r(gd_t *, ulong) __attribute__ ((noreturn));
/**
- * board_init_f_mem() - Allocate global data and set stack position
+ * ulong board_init_f_alloc_reserve - allocate reserved area
*
* This function is called by each architecture very early in the start-up
- * code to set up the environment for board_init_f(). It allocates space for
- * global_data (see include/asm-generic/global_data.h) and places the stack
- * below this.
+ * code to allow the C runtime to reserve space on the stack for writable
+ * 'globals' such as GD and the malloc arena.
*
- * This function requires a stack[1] Normally this is at @top. The function
- * starts allocating space from 64 bytes below @top. First it creates space
- * for global_data. Then it calls arch_setup_gd() which sets gd to point to
- * the global_data space and can reserve additional bytes of space if
- * required). Finally it allocates early malloc() memory
- * (CONFIG_SYS_MALLOC_F_LEN). The new top of the stack is just below this,
- * and it returned by this function.
+ * @top: top of the reserve area, growing down.
+ * @return: bottom of reserved area
+ */
+ulong board_init_f_alloc_reserve(ulong top);
+
+/**
+ * board_init_f_init_reserve - initialize the reserved area(s)
*
- * [1] Strictly speaking it would be possible to implement this function
- * in C on many archs such that it does not require a stack. However this
- * does not seem hugely important as only 64 byte are wasted. The 64 bytes
- * are used to handle the calling standard which generally requires pushing
- * addresses or registers onto the stack. We should be able to get away with
- * less if this becomes important.
+ * This function is called once the C runtime has allocated the reserved
+ * area on the stack. It must initialize the GD at the base of that area.
*
- * @top: Top of available memory, also normally the top of the stack
- * @return: New stack location
+ * @base: top from which reservation was done
*/
-ulong board_init_f_mem(ulong top);
+void board_init_f_init_reserve(ulong base);
/**
* arch_setup_gd() - Set up the global_data pointer