[Xen-devel] [PATCH 2/4] xen/arm64: do not clobber callee saved register in early_putch

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

x23 is callee saved in the ARM 64 bit calling convention. Use x15 instead
which is a temporary register which need not be preserved.

Fixes a random crash during boot.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/arm64/debug.S |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/xen/arch/arm/arm64/debug.S b/xen/arch/arm/arm64/debug.S
index f0c7761..38b7c74 100644
--- a/xen/arch/arm/arm64/debug.S
+++ b/xen/arch/arm/arm64/debug.S
@@ -27,9 +27,9 @@
 /* Print a character on the UART - this function is called by C
  * x0: character to print */
 early_putch:
-        ldr   x23, =FIXMAP_ADDR(FIXMAP_CONSOLE)
-        early_uart_ready x23, 1
-        early_uart_transmit x23, w0
+        ldr   x15, =FIXMAP_ADDR(FIXMAP_CONSOLE)
+        early_uart_ready x15, 1
+        early_uart_transmit x15, w0
         ret
 
 /*
-- 
1.7.2.5


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel