[PATCH v8 6/8] arm: Get bloblist from boot arguments

[Raymond Mao]

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 at linaro.org>
---
Changes in v2
- Remove low level code for copying boot arguments.
- Refactor board_fdt_blob_setup() and remove direct access of gd->bloblist.
Changes in v3
- Optimize board_bloblist_from_boot_arg().
Changes in v4
- Move the function as an Arm-arch library instead of a board-specific one.
Changes in V5
- Drop the dependence on OF_BOARD.
- Move external declaration to header file.
- Adjust the position of BLOBLIST in defconfig file.
Changes in V6
- Drop imply OF_HAS_PRIOR_STAGE from qemu-arm.
Changes in V7
- Revert changes in V6.
- Remove BLOBLIST_ settings from qemu_arm64_defconfig.

 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 at 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 at 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_ */
-- 
2.25.1