From fc61de3ff66053e517946b2aee8ada9f2d510edc Mon Sep 17 00:00:00 2001
From: Raymond Mao <raymond.mao@linaro.org>
Date: Sat, 3 Feb 2024 08:36:25 -0800
Subject: [PATCH] arm: Get bloblist from boot arguments

Add arch custom function to get bloblist from boot arguments.
Check whether boot arguments aligns with the register conventions
defined in FW Handoff spec v0.9.

Signed-off-by: Raymond Mao <raymond.mao@linaro.org>
---
 arch/arm/lib/Makefile   |  2 ++
 arch/arm/lib/xferlist.c | 25 +++++++++++++++++++++++++
 arch/arm/lib/xferlist.h | 19 +++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 arch/arm/lib/xferlist.c
 create mode 100644 arch/arm/lib/xferlist.h

diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index b1bcd37466..67275fba61 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -85,6 +85,8 @@ obj-y	+= psci-dt.o
 
 obj-$(CONFIG_DEBUG_LL)	+= debug.o
 
+obj-$(CONFIG_BLOBLIST)  += xferlist.o
+
 # For EABI conformant tool chains, provide eabi_compat()
 ifneq (,$(findstring -mabi=aapcs-linux,$(PLATFORM_CPPFLAGS)))
 extra-y	+= eabi_compat.o
diff --git a/arch/arm/lib/xferlist.c b/arch/arm/lib/xferlist.c
new file mode 100644
index 0000000000..f9c5d88bd4
--- /dev/null
+++ b/arch/arm/lib/xferlist.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Linaro Limited
+ * Author: Raymond Mao <raymond.mao@linaro.org>
+ */
+#include <linux/types.h>
+#include <errno.h>
+#include <bloblist.h>
+#include "xferlist.h"
+
+int xferlist_from_boot_arg(ulong addr, ulong size)
+{
+	int ret;
+
+	ret = bloblist_check(saved_args[3], size);
+	if (ret)
+		return ret;
+
+	ret = bloblist_check_reg_conv(saved_args[0], saved_args[2],
+				      saved_args[1]);
+	if (ret)
+		return ret;
+
+	return bloblist_reloc((void *)addr, size);
+}
diff --git a/arch/arm/lib/xferlist.h b/arch/arm/lib/xferlist.h
new file mode 100644
index 0000000000..60d79c1a8e
--- /dev/null
+++ b/arch/arm/lib/xferlist.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0+ BSD-3-Clause */
+/*
+ * Copyright (C) 2023 Linaro Limited
+ * Author: Raymond Mao <raymond.mao@linaro.org>
+ */
+
+#ifndef _XFERLIST_H_
+#define _XFERLIST_H_
+
+/*
+ * Boot parameters saved from start.S
+ * saved_args[0]: FDT base address
+ * saved_args[1]: Bloblist signature
+ * saved_args[2]: must be 0
+ * saved_args[3]: Bloblist base address
+ */
+extern unsigned long saved_args[];
+
+#endif /* _XFERLIST_H_ */