[PATCH 14/21] MIPS: clean up barebox proper entry point

[Denis Orlov]

For MIPS, we don't actually have boards which lack PBL in the resulting
image. As such, the code in _start() is mostly redundant: the stack was
setup in ENTRY_FUNCTION_END, while copying the code to the link location
is not needed - it should already be executing at TEXT_BASE, where we
have decompressed it. Other than that, disabling interrupts with
watchpoints and enabling 64-bit addressing was already moved into PBL,
so we don't really need to repeat it there.

Replace the assembly implementation of _start() with the C one, as the
only thing it now does is jump straight into 'relocate_code()'.

Signed-off-by: Denis Orlov <denorl2009 at gmail.com>
---
 arch/mips/boot/start.S | 46 ------------------------------------------
 arch/mips/boot/start.c | 17 ++++++++++++++++
 2 files changed, 17 insertions(+), 46 deletions(-)
 delete mode 100644 arch/mips/boot/start.S
 create mode 100644 arch/mips/boot/start.c

diff --git a/arch/mips/boot/start.S b/arch/mips/boot/start.S
deleted file mode 100644
index 30828ad9ef..0000000000
--- a/arch/mips/boot/start.S
+++ /dev/null
@@ -1,46 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Startup Code for MIPS CPU
- *
- * Copyright (C) 2011, 2015 Antony Pavlov <antonynpavlov at gmail.com>
- */
-
-#include <asm/pbl_macros.h>
-
-	.set noreorder
-	.section ".text_entry"
-	.align 4
-
-EXPORT(_start)
-
-	mips_barebox_10h
-
-	/* save dtb pointer */
-	move	s0, a0
-	move	s1, a1
-	move	s2, a2
-
-	/* disable watchpoints */
-	mtc0	zero, CP0_WATCHLO
-	mtc0	zero, CP0_WATCHHI
-
-	mips_disable_interrupts
-
-	mips64_enable_64bit_addressing
-
-	copy_to_link_location _start
-
-	stack_setup
-
-	/* restore dtb pointer */
-	move	a0, s0
-	move	a1, s1
-	move	a2, s2
-	PTR_LA	v0, relocate_code
-	jal	v0
-	 nop
-
-	/* No return */
-__error:
-	b __error
-	 nop
diff --git a/arch/mips/boot/start.c b/arch/mips/boot/start.c
new file mode 100644
index 0000000000..81603c8d7a
--- /dev/null
+++ b/arch/mips/boot/start.c
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Startup Code for MIPS CPU
+ *
+ * Copyright (C) 2011, 2015 Antony Pavlov <antonynpavlov at gmail.com>
+ */
+
+#include <linux/kernel.h>
+
+void __noreturn _start(void *fdt, u32 fdt_size, u32 relocaddr);
+void __noreturn relocate_code(void *fdt, u32 fdt_size, u32 relocaddr);
+
+void __noreturn __section(.text_entry) _start(void *fdt, u32 fdt_size,
+					      u32 relocaddr)
+{
+	relocate_code(fdt, fdt_size, relocaddr);
+}
-- 
2.41.0