Re: build musl for armv7m

["Zhao, Weiming" <weimingz@codeaurora.org>]

[-- Attachment #1: Type: text/plain, Size: 922 bytes --]

Fixed.

Btw, can we make exit() weak function? (patch attached)

This allows user code to redefine it because in baremetal environment, 
sometime we want to customize it. For example, some code never exits, so 
we can define a dummy exit() and thus save code size.


On 6/22/2016 4:26 PM, Rich Felker wrote:
> On Wed, Jun 22, 2016 at 01:37:38PM -0700, Zhao, Weiming wrote:
>> How about using the following test?
>>
>> !defined(__thumb__) || (__ARM_ARCH_7A__ || __ARM_ARCH_7R__ ||
>> __ARM_ARCH > 7)
>>
>> Because I think those instructions are ISA related, not just
>> arm/thumb. For example, using -mcpu=cortex-a8 -mthumb, the original
>> code still works.  So if only testing __thumb__, the armv7-a thumb
>> mode will fall into the slow path too.
> I think perhaps __thumb2__ is what you're looking for...?
>
> Rich

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation


[-- Attachment #2: patch.diff --]
[-- Type: text/plain, Size: 1602 bytes --]

diff --git a/src/setjmp/arm/longjmp.s b/src/setjmp/arm/longjmp.s
index e28d8f3..e9b9b32 100644
--- a/src/setjmp/arm/longjmp.s
+++ b/src/setjmp/arm/longjmp.s
@@ -8,7 +8,9 @@ longjmp:
 	mov ip,r0
 	movs r0,r1
 	moveq r0,#1
-	ldmia ip!, {v1,v2,v3,v4,v5,v6,sl,fp,sp,lr}
+	ldmia ip!, {v1,v2,v3,v4,v5,v6,sl,fp}
+	ldr sp, [ip]!
+	ldr lr, [ip]!
 
 	adr r1,1f
 	ldr r2,1f
diff --git a/src/setjmp/arm/setjmp.s b/src/setjmp/arm/setjmp.s
index 8779163..fd380b0 100644
--- a/src/setjmp/arm/setjmp.s
+++ b/src/setjmp/arm/setjmp.s
@@ -9,7 +9,9 @@ __setjmp:
 _setjmp:
 setjmp:
 	mov ip,r0
-	stmia ip!,{v1,v2,v3,v4,v5,v6,sl,fp,sp,lr}
+	stmia ip!,{v1,v2,v3,v4,v5,v6,sl,fp}
+	str sp, [ip]!
+	str lr, [ip]!
 	mov r0,#0
 
 	adr r1,1f
diff --git a/src/string/arm/memcpy_le.S b/src/string/arm/memcpy_le.S
index 4db4844..df9f5c8 100644
--- a/src/string/arm/memcpy_le.S
+++ b/src/string/arm/memcpy_le.S
@@ -241,7 +241,12 @@ non_congruent:
 	beq     2f
 	ldr     r5, [r1], #4
 	sub     r2, r2, #4
+#if !defined(__thumb2__) || (__ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH > 7)
 	orr     r4, r3, r5,             lsl lr
+#else
+	lsl     r4, r5, lr
+	orr     r4, r3, r4
+#endif
 	mov     r3, r5,                 lsr r12
 	str     r4, [r0], #4
 	cmp     r2, #4
@@ -348,7 +353,12 @@ less_than_thirtytwo:
 
 1:      ldr     r5, [r1], #4
 	sub     r2, r2, #4
+#if !defined(__thumb2__) || (__ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH > 7)
 	orr     r4, r3, r5,             lsl lr
+#else
+	lsl     r4, r5, lr
+	orr     r4, r3, r4
+#endif
 	mov     r3,     r5,                     lsr r12
 	str     r4, [r0], #4
 	cmp     r2, #4

[-- Attachment #3: patch_exit.diff --]
[-- Type: text/plain, Size: 305 bytes --]

diff --git a/src/exit/exit.c b/src/exit/exit.c
index bf7835a..694d277 100644
--- a/src/exit/exit.c
+++ b/src/exit/exit.c
@@ -25,6 +25,7 @@ static void libc_exit_fini(void)
 
 weak_alias(libc_exit_fini, __libc_exit_fini);
 
+__attribute__((__weak__))
 _Noreturn void exit(int code)
 {
 	__funcs_on_exit();