[U-Boot] [PATCH v1] ppc4xx: Fix platform support

[dirk.eibach at gdsys.cc]

From: Dirk Eibach <dirk.eibach at gdsys.cc>

Commit "ecc3066 Fix board init code to respect the C runtime environment"
broke platform support for ppc4xx.
start.S prepares a stackframe that is later rendered unusable by appending
the reserved space for global data.
Instead the reserved space has to be put first. Then the stackframe can
be pushed.

I can only test the 405EP OCM case. At least all other ppc4xx boards still
build.

Signed-off-by: Dirk Eibach <dirk.eibach at gdsys.cc>
---

 arch/powerpc/cpu/ppc4xx/start.S | 66 ++++++++++++++++++++++++++++-------------
 1 file changed, 45 insertions(+), 21 deletions(-)

diff --git a/arch/powerpc/cpu/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S
index b432b18..f357726 100644
--- a/arch/powerpc/cpu/ppc4xx/start.S
+++ b/arch/powerpc/cpu/ppc4xx/start.S
@@ -743,8 +743,16 @@ _start:
 	/*----------------------------------------------------------------*/
 	/* Setup the stack in internal SRAM */
 	/*----------------------------------------------------------------*/
-	lis	r1,CONFIG_SYS_INIT_RAM_ADDR at h
-	ori	r1,r1,CONFIG_SYS_INIT_SP_OFFSET at l
+	lis	r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@h
+	ori	r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@l
+	/*
+	 * Reserve space for globals and store address for initialization
+	 * with board_init_f_init_reserve() in r14
+	 */
+	mr	r3, r1
+	bl	board_init_f_alloc_reserve
+	mr	r1, r3
+	mr	r14, r3
 	li	r0,0
 	stwu	r0,-4(r1)
 	stwu	r0,-4(r1)		/* Terminate call chain */
@@ -760,13 +768,9 @@ _start:
 #endif
 
 	bl	cpu_init_f	/* run low-level CPU init code	   (from Flash) */
-	mr	r3, r1
-	bl	board_init_f_alloc_reserve
-	mr	r1, r3
+	/* address for globals was stored in r14 */
+	mr	r3, r14
 	bl	board_init_f_init_reserve
-	li	r0,0
-	stwu	r0, -4(r1)
-	stwu	r0, -4(r1)
 	li	r3, 0
 	bl	board_init_f
 	/* NOTREACHED - board_init_f() does not return */
@@ -831,8 +835,16 @@ _start:
 	 * for their primordial stack, setup stack here directly after the
 	 * SDRAM is initialized in ext_bus_cntlr_init.
 	 */
-	lis	r1, CONFIG_SYS_INIT_RAM_ADDR at h
-	ori	r1,r1,CONFIG_SYS_INIT_SP_OFFSET /* set up the stack in SDRAM */
+	lis	r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@h
+	ori	r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@l
+	/*
+	 * Reserve space for globals and store address for initialization
+	 * with board_init_f_init_reserve() in r14
+	 */
+	mr	r3, r1
+	bl	board_init_f_alloc_reserve
+	mr	r1, r3
+	mr	r14, r3
 
 	li	r0, 0			/* Make room for stack frame header and */
 	stwu	r0, -4(r1)		/* clear final stack frame so that	*/
@@ -972,8 +984,16 @@ _start:
 	 * Load the initial stack pointer and data area and convert the size,
 	 * in bytes, to the number of words to initialize to a known value.
 	 */
-	lis	r1, CONFIG_SYS_INIT_RAM_ADDR at h
-	ori	r1, r1, CONFIG_SYS_INIT_SP_OFFSET at l
+	lis	r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@h
+	ori	r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@l
+	/*
+	 * Reserve space for globals and store address for initialization
+	 * with board_init_f_init_reserve() in r14
+	 */
+	mr	r3, r1
+	bl	board_init_f_alloc_reserve
+	mr	r1, r3
+	mr	r14, r3
 
 	lis	r4, (CONFIG_SYS_INIT_RAM_SIZE >> 2)@h
 	ori	r4, r4, (CONFIG_SYS_INIT_RAM_SIZE >> 2)@l
@@ -993,6 +1013,7 @@ _start:
 	 * Make room for stack frame header and clear final stack frame so
 	 * that stack backtraces terminate cleanly.
 	 */
+	li	r0, 0
 	stwu	r0, -4(r1)
 	stwu	r0, -4(r1)
 
@@ -1011,10 +1032,16 @@ _start:
 	/*
 	 * Stack in OCM.
 	 */
-
-	/* Set up Stack at top of OCM */
-	lis	r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_SP_OFFSET)@h
-	ori	r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_SP_OFFSET)@l
+	lis	r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@h
+	ori	r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_RAM_SIZE)@l
+	/*
+	 * Reserve space for globals and store address for initialization
+	 * with board_init_f_init_reserve() in r14
+	 */
+	mr	r3, r1
+	bl	board_init_f_alloc_reserve
+	mr	r1, r3
+	mr	r14, r3
 
 	/* Set up a zeroized stack frame so that backtrace works right */
 	li	r0, 0
@@ -1035,12 +1062,9 @@ _start:
 	GET_GOT			/* initialize GOT access			*/
 
 	bl	cpu_init_f	/* run low-level CPU init code	   (from Flash) */
-	mr	r3, r1
-	bl	board_init_f_alloc_reserve
-	mr	r1, r3
+	/* address for globals was stored in r14 */
+	mr	r3, r14
 	bl	board_init_f_init_reserve
-	stwu	r0, -4(r1)
-	stwu	r0, -4(r1)
 	li	r3, 0
 	bl	board_init_f	/* run first part of init code (from Flash)	*/
 	/* NOTREACHED - board_init_f() does not return */
-- 
2.1.3