Re: [Qemu-devel] [PATCH] linux-user: ARM: Ignore immediate value for svc in thumb mode

[Peter Maydell]

On 29 May 2012 16:30, Alexander Graf ag...@suse.de wrote:
 When running in thumb mode, Linux doesn't evaluate the immediate value
 of the svc instruction, but instead just always assumes the syscall number
 to be in r7.

 This fixes executing go_bootstrap while building go for me.

 Signed-off-by: Alexander Graf ag...@suse.de

Yep, there's no OABI back-compat for thumb so it is always EABI.
(I think the code emitting Thumb SVCs with non-zero immediate
values is probably broken though.)

Reviewed-by: Peter Maydell peter.mayd...@linaro.org

-- PMM

[Qemu-devel] [PATCH] linux-user: ARM: Ignore immediate value for svc in thumb mode

[Alexander Graf]

When running in thumb mode, Linux doesn't evaluate the immediate value
of the svc instruction, but instead just always assumes the syscall number
to be in r7.

This fixes executing go_bootstrap while building go for me.

Signed-off-by: Alexander Graf ag...@suse.de
---
 linux-user/main.c |3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 191b750..a7fefe7 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -822,8 +822,7 @@ void cpu_loop(CPUARMState *env)
 } else if (n == ARM_NR_semihosting
|| n == ARM_NR_thumb_semihosting) {
 env-regs[0] = do_arm_semihosting (env);
-} else if (n == 0 || n = ARM_SYSCALL_BASE
-   || (env-thumb  n == ARM_THUMB_SYSCALL)) {
+} else if (n == 0 || n = ARM_SYSCALL_BASE || env-thumb) {
 /* linux syscall */
 if (env-thumb || n == 0) {
 n = env-regs[7];
-- 
1.6.0.2