[RFC PATCH 02/10] arm: add initjmp()

[Jerome Forissier]

Implement initjmp() for Arm.

Signed-off-by: Jerome Forissier <jerome.foriss...@linaro.org>
---
 arch/Kconfig                  |  1 +
 arch/arm/include/asm/setjmp.h |  1 +
 arch/arm/lib/setjmp.S         | 11 +++++++++++
 arch/arm/lib/setjmp_aarch64.S |  9 +++++++++
 4 files changed, 22 insertions(+)

diff --git a/arch/Kconfig b/arch/Kconfig
index 8d5b54031b3..57695fada8d 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -94,6 +94,7 @@ config ARC
 config ARM
        bool "ARM architecture"
        select HAVE_SETJMP
+       select HAVE_INITJMP
        select ARCH_SUPPORTS_LTO
        select CREATE_ARCH_SYMLINK
        select HAVE_PRIVATE_LIBGCC if !ARM64
diff --git a/arch/arm/include/asm/setjmp.h b/arch/arm/include/asm/setjmp.h
index 662bec86321..1ad5b500f2a 100644
--- a/arch/arm/include/asm/setjmp.h
+++ b/arch/arm/include/asm/setjmp.h
@@ -23,5 +23,6 @@ typedef struct jmp_buf_data jmp_buf[1];
 
 int setjmp(jmp_buf jmp);
 void longjmp(jmp_buf jmp, int ret);
+int initjmp(jmp_buf jmp, void __noreturn (*func)(void), void *stack_top);
 
 #endif /* _SETJMP_H_ */
diff --git a/arch/arm/lib/setjmp.S b/arch/arm/lib/setjmp.S
index 2f041aeef01..320ddea85f9 100644
--- a/arch/arm/lib/setjmp.S
+++ b/arch/arm/lib/setjmp.S
@@ -34,3 +34,14 @@ ENTRY(longjmp)
        ret  lr
 ENDPROC(longjmp)
 .popsection
+
+.pushsection .text.initjmp, "ax"
+ENTRY(initjmp)
+       stm  a1, {v1-v8}
+       /* a2: entry point address, a3: stack top */
+       str  a3, [a1, #32]  /* where setjmp would save sp */
+       str  a2, [a1, #36]  /* where setjmp would save lr */
+       mov  a1, #0
+       ret  lr
+ENDPROC(initjmp)
+.popsection
diff --git a/arch/arm/lib/setjmp_aarch64.S b/arch/arm/lib/setjmp_aarch64.S
index 1b8d000eb48..074320d25fb 100644
--- a/arch/arm/lib/setjmp_aarch64.S
+++ b/arch/arm/lib/setjmp_aarch64.S
@@ -39,3 +39,12 @@ ENTRY(longjmp)
        ret
 ENDPROC(longjmp)
 .popsection
+
+.pushsection .text.initjmp, "ax"
+ENTRY(initjmp)
+       /* x1: entry point address, x2: stack top */
+       stp x1, x2, [x0,#88]
+       mov  x0, #0
+       ret
+ENDPROC(initjmp)
+.popsection
-- 
2.43.0