[Xen-changelog] [xen staging] xen/arm32: head: Introduce print_reg

[patchbot@xxxxxxx]

commit 854e7d6224063af64b5a6750415bccd880e292fa
Author:     Julien Grall <julien.grall@xxxxxxx>
AuthorDate: Mon Apr 15 23:11:42 2019 +0100
Commit:     Julien Grall <julien.grall@xxxxxxx>
CommitDate: Sat Sep 7 12:10:22 2019 +0100

    xen/arm32: head: Introduce print_reg
    
    At the moment, the user should save r14/lr if it cares about it.
    
    Follow-up patches will introduce more use of putn in place where lr
    should be preserved.
    
    Furthermore, any user of putn should also move the value to register r0
    if it was stored in a different register.
    
    For convenience, a new macro is introduced to print a given register.
    The macro will take care for us to move the value to r0 and also
    preserve lr.
    
    Lastly the new macro is used to replace all the callsite of putn. This
    will simplify rework/review later on.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/arm32/head.S | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index fd3a273550..c4ee06ba93 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -79,8 +79,25 @@
 98:     .asciz _s          ;\
         .align 2           ;\
 99:
+
+/*
+ * Macro to print the value of register \rb
+ *
+ * Clobbers r0 - r4
+ */
+.macro print_reg rb
+        mov   r0, \rb
+        mov   r4, lr
+        bl    putn
+        mov   lr, r4
+.endm
+
 #else /* CONFIG_EARLY_PRINTK */
 #define PRINT(s)
+
+.macro print_reg rb
+.endm
+
 #endif /* !CONFIG_EARLY_PRINTK */
 
         .arm
@@ -159,8 +176,7 @@ GLOBAL(init_secondary)
 #ifdef CONFIG_EARLY_PRINTK
         mov_w r11, EARLY_UART_BASE_ADDRESS   /* r11 := UART base address */
         PRINT("- CPU ")
-        mov   r0, r7
-        bl    putn
+        print_reg r7
         PRINT(" booting -\r\n")
 #endif
 
@@ -211,8 +227,7 @@ skip_bss:
         bne   1f
         mov   r4, r0
         PRINT("- Missing processor info: ")
-        mov   r0, r4
-        bl    putn
+        print_reg r4
         PRINT(" -\r\n")
         b     fail
 1:
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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