common: Rewrite hiding the end of memory

As the name may be confusing, the CONFIG_SYS_MEM_TOP_HIDE reserves some memory from the end of ram, tracked by gd->ram_size. It is not always the top of u-boot visible memory. Rewrite the macro with a weak function to provide flexibility for complex calcuation. Legacy use of this macro is still supported. Signed-off-by: York Sun <yorksun@freescale.com> Reviewed-by: Simon Glass <sjg@chromium.org>

common: Rewrite hiding the end of memory
As the name may be confusing, the CONFIG_SYS_MEM_TOP_HIDE reserves some memory from the end of ram, tracked by gd->ram_size. It is not always the top of u-boot visible memory. Rewrite the macro with a weak function to provide flexibility for complex calcuation. Legacy use of this macro is still supported. Signed-off-by: York Sun <yorksun@freescale.com> Reviewed-by: Simon Glass <sjg@chromium.org>
York Sun · Eric Lee · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent c107c0c05c
Showing 2 changed files with 16 additions and 9 deletions Side-by-side Diff
README
common/board_f.c
@@ -3877,7 +3877,7 @@
 		the RAM base is not zero, or RAM is divided into banks,
 		this variable needs to be recalcuated to get the address.
  
-- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
+- CONFIG_SYS_MEM_TOP_HIDE:
 		If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
 		this specified memory area will get subtracted from the top
 		(end) of RAM and won't get "touched" at all by U-Boot. By
@@ -317,6 +317,15 @@
 	return gd->ram_top;
 }
  
+__weak phys_size_t board_reserve_ram_top(phys_size_t ram_size)
+{
+#ifdef CONFIG_SYS_MEM_TOP_HIDE
+	return ram_size - CONFIG_SYS_MEM_TOP_HIDE;
+#else
+	return ram_size;
+#endif
+}
+
 static int setup_dest_addr(void)
 {
 	debug("Monitor len: %08lX\n", gd->mon_len);
  
  
@@ -333,19 +342,17 @@
 	 */
 	gd->secure_ram = gd->ram_size;
 #endif
-#if defined(CONFIG_SYS_MEM_TOP_HIDE)
 	/*
 	 * Subtract specified amount of memory to hide so that it won't
 	 * get "touched" at all by U-Boot. By fixing up gd->ram_size
 	 * the Linux kernel should now get passed the now "corrected"
-	 * memory size and won't touch it either. This should work
-	 * for arch/ppc and arch/powerpc. Only Linux board ports in
-	 * arch/powerpc with bootwrapper support, that recalculate the
-	 * memory size from the SDRAM controller setup will have to
-	 * get fixed.
+	 * memory size and won't touch it either. This has been used
+	 * by arch/powerpc exclusively. Now ARMv8 takes advantage of
+	 * thie mechanism. If memory is split into banks, addresses
+	 * need to be calculated.
 	 */
-	gd->ram_size -= CONFIG_SYS_MEM_TOP_HIDE;
-#endif
+	gd->ram_size = board_reserve_ram_top(gd->ram_size);
+
 #ifdef CONFIG_SYS_SDRAM_BASE
 	gd->ram_top = CONFIG_SYS_SDRAM_BASE;
 #endif
...	...	@@ -3877,7 +3877,7 @@
3877	3877	the RAM base is not zero, or RAM is divided into banks,
3878	3878	this variable needs to be recalcuated to get the address.
3879	3879
3880		-- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
	3880	+- CONFIG_SYS_MEM_TOP_HIDE:
3881	3881	If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3882	3882	this specified memory area will get subtracted from the top
3883	3883	(end) of RAM and won't get "touched" at all by U-Boot. By
...	...	@@ -317,6 +317,15 @@
317	317	return gd->ram_top;
318	318	}
319	319
	320	+__weak phys_size_t board_reserve_ram_top(phys_size_t ram_size)
	321	+{
	322	+#ifdef CONFIG_SYS_MEM_TOP_HIDE
	323	+ return ram_size - CONFIG_SYS_MEM_TOP_HIDE;
	324	+#else
	325	+ return ram_size;
	326	+#endif
	327	+}
	328	+
320	329	static int setup_dest_addr(void)
321	330	{
322	331	debug("Monitor len: %08lX\n", gd->mon_len);
323	332
324	333
...	...	@@ -333,19 +342,17 @@
333	342	*/
334	343	gd->secure_ram = gd->ram_size;
335	344	#endif
336		-#if defined(CONFIG_SYS_MEM_TOP_HIDE)
337	345	/*
338	346	* Subtract specified amount of memory to hide so that it won't
339	347	* get "touched" at all by U-Boot. By fixing up gd->ram_size
340	348	* the Linux kernel should now get passed the now "corrected"
341		- * memory size and won't touch it either. This should work
342		- * for arch/ppc and arch/powerpc. Only Linux board ports in
343		- * arch/powerpc with bootwrapper support, that recalculate the
344		- * memory size from the SDRAM controller setup will have to
345		- * get fixed.
	349	+ * memory size and won't touch it either. This has been used
	350	+ * by arch/powerpc exclusively. Now ARMv8 takes advantage of
	351	+ * thie mechanism. If memory is split into banks, addresses
	352	+ * need to be calculated.
346	353	*/
347		- gd->ram_size -= CONFIG_SYS_MEM_TOP_HIDE;
348		-#endif
	354	+ gd->ram_size = board_reserve_ram_top(gd->ram_size);
	355	+
349	356	#ifdef CONFIG_SYS_SDRAM_BASE
350	357	gd->ram_top = CONFIG_SYS_SDRAM_BASE;
351	358	#endif