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| author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2020-10-15 13:25:14 +0900 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2020-10-22 11:26:14 -0400 |
| commit | 3a51b2a2c3cedc0d2a9ce981b8e00ab8cefcb6b7 (patch) | |
| tree | 26fa9a221f069691d0364ededd0b39c04b5c2546 | |
| parent | 18426bf02217de2e9bb2b41eaa74d769892c55ef (diff) | |
| download | u-boot-3a51b2a2c3cedc0d2a9ce981b8e00ab8cefcb6b7.tar.gz | |
arch: arm/xen: add putc() for debugging
This new function, xen_debug_putc(), is intended to be used to
enable CONFIG_DEBUG_UART on xen guest.
Please note that the underlying functionality in Xen is available
only when Xen is configured with !NDEBUG but is much simpler than
a generic HYPERVISOR_console_io().
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
| -rw-r--r-- | arch/arm/include/asm/xen/hypercall.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h index a4fd077079..121ccfcc60 100644 --- a/arch/arm/include/asm/xen/hypercall.h +++ b/arch/arm/include/asm/xen/hypercall.h @@ -19,4 +19,10 @@ int HYPERVISOR_sched_op(int cmd, void *arg); int HYPERVISOR_event_channel_op(int cmd, void *arg); unsigned long HYPERVISOR_hvm_op(int op, void *arg); int HYPERVISOR_memory_op(unsigned int cmd, void *arg); + +static inline void xen_debug_putc(int c) +{ + register int v __asm__ ("x0") = c; + __asm__ __volatile__("hvc 0xfffe" : "=r" (v) : "0" (v)); +} #endif /* _ASM_ARM_XEN_HYPERCALL_H */ |