Hi Everybody,
I recently did a cross-compiling using clang (built with host=x86, target=arm)
with the following command:
> clang -march=armv7-a -mfloat-abi=soft -ccc-host-triple
arm-none-linux-gnueabi -integrated-as main.c -o main.o -c
and get error message:
-------------------------------------------------------
main.c:9:9: error: instruction requires: thumb2
"ldrex %[oldValue], [%[ptr], #0]\n" // oldValue = *ptr
^
<inline asm>:1:2: note: instantiated into assembly here
ldrex r6, [r4, #0]
^
main.c:11:3: error: instruction requires: thumb2
"strexeq %[failed], %[newValue], [%[ptr], #0]\n"
^
<inline asm>:3:1: note: instantiated into assembly here
strexeq r5, lr, [r4, #0]
^
2 errors generated.
-------------------------------------------------------
In the main.c, some ARM assembly are embedded which contains instructions
ldrex, strexeq. I don't know what the message suggests since the cpu
specified does support thumb2. Could someone help? Thanks.
- Lei
On Thu, Aug 16, 2012 at 12:55 PM, Lei Zhao <leizhao833 at gmail.com> wrote:> Hi Everybody, > > I recently did a cross-compiling using clang (built with host=x86, target=arm) with the following command: > > > clang -march=armv7-a -mfloat-abi=soft -ccc-host-triple arm-none-linux-gnueabi -integrated-as main.c -o main.o -c > > and get error message: > > ------------------------------------------------------- > main.c:9:9: error: instruction requires: thumb2 > "ldrex %[oldValue], [%[ptr], #0]\n" // oldValue = *ptr > ^ > <inline asm>:1:2: note: instantiated into assembly here > ldrex r6, [r4, #0] > ^ > main.c:11:3: error: instruction requires: thumb2 > "strexeq %[failed], %[newValue], [%[ptr], #0]\n" > ^ > <inline asm>:3:1: note: instantiated into assembly here > strexeq r5, lr, [r4, #0] > ^ > 2 errors generated. > ------------------------------------------------------- > > In the main.c, some ARM assembly are embedded which contains instructions ldrex, strexeq. I don't know what the message suggests since the cpu specified does support thumb2. Could someone help? Thanks.Try "-mthumb". -Eli
It works. Thanks. - Lei On Aug 16, 2012, at 4:00 PM, Eli Friedman wrote:> On Thu, Aug 16, 2012 at 12:55 PM, Lei Zhao <leizhao833 at gmail.com> wrote: >> Hi Everybody, >> >> I recently did a cross-compiling using clang (built with host=x86, target=arm) with the following command: >> >>> clang -march=armv7-a -mfloat-abi=soft -ccc-host-triple arm-none-linux-gnueabi -integrated-as main.c -o main.o -c >> >> and get error message: >> >> ------------------------------------------------------- >> main.c:9:9: error: instruction requires: thumb2 >> "ldrex %[oldValue], [%[ptr], #0]\n" // oldValue = *ptr >> ^ >> <inline asm>:1:2: note: instantiated into assembly here >> ldrex r6, [r4, #0] >> ^ >> main.c:11:3: error: instruction requires: thumb2 >> "strexeq %[failed], %[newValue], [%[ptr], #0]\n" >> ^ >> <inline asm>:3:1: note: instantiated into assembly here >> strexeq r5, lr, [r4, #0] >> ^ >> 2 errors generated. >> ------------------------------------------------------- >> >> In the main.c, some ARM assembly are embedded which contains instructions ldrex, strexeq. I don't know what the message suggests since the cpu specified does support thumb2. Could someone help? Thanks. > > Try "-mthumb". > > -Eli
It works. But a follow-up question: why do I have to compile it to thumb mode in order to pass the compilation? Is there a way to make it compile to regular arm mode? Thanks. - Lei On Aug 16, 2012, at 4:00 PM, Eli Friedman wrote:> On Thu, Aug 16, 2012 at 12:55 PM, Lei Zhao <leizhao833 at gmail.com> wrote: >> Hi Everybody, >> >> I recently did a cross-compiling using clang (built with host=x86, target=arm) with the following command: >> >>> clang -march=armv7-a -mfloat-abi=soft -ccc-host-triple arm-none-linux-gnueabi -integrated-as main.c -o main.o -c >> >> and get error message: >> >> ------------------------------------------------------- >> main.c:9:9: error: instruction requires: thumb2 >> "ldrex %[oldValue], [%[ptr], #0]\n" // oldValue = *ptr >> ^ >> <inline asm>:1:2: note: instantiated into assembly here >> ldrex r6, [r4, #0] >> ^ >> main.c:11:3: error: instruction requires: thumb2 >> "strexeq %[failed], %[newValue], [%[ptr], #0]\n" >> ^ >> <inline asm>:3:1: note: instantiated into assembly here >> strexeq r5, lr, [r4, #0] >> ^ >> 2 errors generated. >> ------------------------------------------------------- >> >> In the main.c, some ARM assembly are embedded which contains instructions ldrex, strexeq. I don't know what the message suggests since the cpu specified does support thumb2. Could someone help? Thanks. > > Try "-mthumb". > > -Eli