[PATCH v2 2/6] xen/riscv: introduce reset_stack() function

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

The reason for reset_stack() introduction is that stack should be
reset twice:
1. Before jumping to C world at the start of _start() function.
2. After jumping from 1:1 mapping world.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
Reviewed-by: Alistair Francis <alistair.francis@xxxxxxx>
---
Changes in V2:
  - update the commit message.
  - move out reset_stack() from .text.header to .text.
  - add Reviewed-by: Alistair Francis <alistair.francis@xxxxxxx>.
---
 xen/arch/riscv/riscv64/head.S | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/xen/arch/riscv/riscv64/head.S b/xen/arch/riscv/riscv64/head.S
index 8887f0cbd4..2c0304646a 100644
--- a/xen/arch/riscv/riscv64/head.S
+++ b/xen/arch/riscv/riscv64/head.S
@@ -27,8 +27,16 @@ ENTRY(start)
         add     t3, t3, __SIZEOF_POINTER__
         bltu    t3, t4, .L_clear_bss
 
+        jal     reset_stack
+
+        tail    start_xen
+
+        .section .text, "ax", %progbits
+
+ENTRY(reset_stack)
         la      sp, cpu0_boot_stack
         li      t0, STACK_SIZE
         add     sp, sp, t0
 
-        tail    start_xen
+        ret
+
-- 
2.40.1