[U-Boot] [PATCH v2 2/2] powerpc: mpc83xx: Enable pre-relocation malloc

[Mario Six]

To enable DM on MPC83xx, we need pre-relocation malloc, which is
implemented in this patch.

Signed-off-by: Mario Six <mario.six at gdsys.cc>
---

Changes in v2:

* Switched to r3 to hold SP modifications (as suggested by Joakim Tjernlund)

---
 arch/powerpc/cpu/mpc83xx/cpu_init.c    |  3 +--
 arch/powerpc/cpu/mpc83xx/spl_minimal.c |  4 +---
 arch/powerpc/cpu/mpc83xx/start.S       | 23 +++++++++++++++++++++++
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/cpu/mpc83xx/cpu_init.c b/arch/powerpc/cpu/mpc83xx/cpu_init.c
index f911275b25..3a0916bdbf 100644
--- a/arch/powerpc/cpu/mpc83xx/cpu_init.c
+++ b/arch/powerpc/cpu/mpc83xx/cpu_init.c
@@ -205,8 +205,7 @@ void cpu_init_f (volatile immap_t * im)
 	/* Pointer is writable since we allocated a register for it */
 	gd = (gd_t *) (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET);

-	/* Clear initial global data */
-	memset ((void *) gd, 0, sizeof (gd_t));
+	/* global data region was cleared in start.S */

 	/* system performance tweaking */
 	clrsetbits_be32(&im->arbiter.acr, acr_mask, acr_val);
diff --git a/arch/powerpc/cpu/mpc83xx/spl_minimal.c b/arch/powerpc/cpu/mpc83xx/spl_minimal.c
index 845861eea7..026da12e66 100644
--- a/arch/powerpc/cpu/mpc83xx/spl_minimal.c
+++ b/arch/powerpc/cpu/mpc83xx/spl_minimal.c
@@ -23,9 +23,7 @@ void cpu_init_f (volatile immap_t * im)
 	/* Pointer is writable since we allocated a register for it */
 	gd = (gd_t *) (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET);

-	/* Clear initial global data */
-	for (i = 0; i < sizeof(gd_t); i++)
-		((char *)gd)[i] = 0;
+	/* global data region was cleared in start.S */

 	/* system performance tweaking */

diff --git a/arch/powerpc/cpu/mpc83xx/start.S b/arch/powerpc/cpu/mpc83xx/start.S
index c366f615e7..ff312892bc 100644
--- a/arch/powerpc/cpu/mpc83xx/start.S
+++ b/arch/powerpc/cpu/mpc83xx/start.S
@@ -263,6 +263,29 @@ in_flash:
 	lis	r3, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@h
 	ori	r3, r3, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@l

+	/* r4 = end of GD area */
+	addi r4, r3, GENERATED_GBL_DATA_SIZE
+
+	/* Zero GD area */
+	li	r0, 0
+1:
+	subi	r4, r4, 1
+	stb	r0, 0(r4)
+	cmplw	r3, r4
+	bne	1b
+
+#ifdef CONFIG_SYS_MALLOC_F_LEN
+
+#if CONFIG_SYS_MALLOC_F_LEN + GENERATED_GBL_DATA_SIZE > CONFIG_SYS_INIT_RAM_SIZE
+#error "CONFIG_SYS_MALLOC_F_LEN too large to fit into initial RAM."
+#endif
+
+	/* r3 = new stack pointer / pre-reloc malloc area */
+	subi    r3, r3, CONFIG_SYS_MALLOC_F_LEN
+
+	/* Set pointer to pre-reloc malloc area in GD */
+	stw     r3, GD_MALLOC_BASE(r4)
+#endif
 	li	r0, 0		/* Make room for stack frame header and	*/
 	stwu	r0, -4(r3)	/* clear final stack frame so that	*/
 	stwu	r0, -4(r3)	/* stack backtraces terminate cleanly	*/
--
2.11.0