[U-Boot] [PATCH 2/6] armv8: Implement CONFIG_SYS_MALLOC_F_LEN support

[Thierry Reding <thierry.reding@gmail.com>]

From: Thierry Reding <treding@nvidia.com>

Implement early malloc() support in a similar way as on 32-bit ARM. This
is required for 64-bit Tegra SoCs that initialize from the device tree
just like the earlier 32-bit SoCs.

Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 arch/arm/include/asm/config.h |  4 ----
 arch/arm/lib/crt0_64.S        | 16 ++++++++++++++--
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/config.h b/arch/arm/include/asm/config.h
index be80434dee4d..7a34a0186cb1 100644
--- a/arch/arm/include/asm/config.h
+++ b/arch/arm/include/asm/config.h
@@ -7,10 +7,6 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
-#ifdef __aarch64__
-#define CONFIG_SYS_GENERIC_GLOBAL_DATA
-#endif
-
 #define CONFIG_LMB
 #define CONFIG_SYS_BOOT_RAMDISK_HIGH
 
diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S
index 77563967e517..010efdbf8f3f 100644
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -62,9 +62,21 @@ ENTRY(_main)
  * Set up initial C runtime environment and call board_init_f(0).
  */
 	ldr	x0, =(CONFIG_SYS_INIT_SP_ADDR)
+	mov	x1, x0
 	sub	x0, x0, #GD_SIZE	/* allocate one GD above SP */
-	bic	sp, x0, #0xf	/* 16-byte alignment for ABI compliance */
-	mov	x18, sp			/* GD is above SP */
+	bic	x0, x0, #0xf		/* 16-byte alignment for ABI compliance */
+	mov	x18, x0			/* GD is above SP */
+	mov	sp, x0
+clr_gd:
+	str	xzr, [x0], #8
+	cmp	x0, x1
+	b.lo	clr_gd
+#if defined(CONFIG_SYS_MALLOC_F_LEN)
+	ldr	x0, =CONFIG_SYS_MALLOC_F_LEN
+	sub	x0, sp, x0
+	str	x0, [x18, #GD_MALLOC_BASE]
+#endif
+3:
 	mov	x0, #0
 	bl	board_init_f
 
-- 
2.3.2