ARM: 7737/1: fix kernel decompressor compilation error with CONFIG_DEBUG_SEMIHOSTING

Selecting this option produces:

  AS      arch/arm/boot/compressed/debug.o
arch/arm/boot/compressed/debug.S:4:33: fatal error: mach/debug-macro.S: No such file or directory
compilation terminated.
make[3]: *** [arch/arm/boot/compressed/debug.o] Error 1

The semihosting support cannot be modelled into a senduart macro as
it requires memory space for argument passing.  So the
CONFIG_DEBUG_LL_INCLUDE may not have any sensible value and the include
directive should be omitted.

While at it, let's add proper semihosting output support to the
decompressor.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 28 insertions, 0 deletions

diff --git a/arch/arm/boot/compressed/debug.S b/arch/arm/boot/compressed/debug.S
index 6e8382d5b7a4..5392ee63338f 100644
--- a/arch/arm/boot/compressed/debug.S
+++ b/arch/arm/boot/compressed/debug.S
@@ -1,6 +1,8 @@
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 
+#ifndef CONFIG_DEBUG_SEMIHOSTING
+
 #include CONFIG_DEBUG_LL_INCLUDE
 
 ENTRY(putc)
@@ -10,3 +12,29 @@ ENTRY(putc)
         busyuart r3, r1
         mov      pc, lr
 ENDPROC(putc)
+
+#else
+
+ENTRY(putc)
+        adr     r1, 1f
+        ldmia   r1, {r2, r3}
+        add     r2, r2, r1
+        ldr     r1, [r2, r3]
+        strb    r0, [r1]
+        mov     r0, #0x03               @ SYS_WRITEC
+   ARM( svc     #0x123456       )
+ THUMB( svc     #0xab           )
+        mov     pc, lr
+        .align  2
+1:      .word   _GLOBAL_OFFSET_TABLE_ - .
+        .word   semi_writec_buf(GOT)
+ENDPROC(putc)
+
+        .bss
+        .global semi_writec_buf
+        .type   semi_writec_buf, %object
+semi_writec_buf:
+        .space  4
+        .size   semi_writec_buf, 4
+
+#endif