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[2/2] common/efi: give people some time to read messages when debugging

Message ID 20170920205718.17747-2-tamas@tklengyel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tamas K Lengyel Sept. 20, 2017, 8:57 p.m. UTC 
From: Tamas K Lengyel <lengyelt@ainfosec.com>

The EFI messages flash by so fast that it is impossible to catch them without
a serial debugger attached. Sometimes though we don't have that available so
having some time to read the messages off the screen is valuable.

Signed-off-by: Tamas K Lengyel <lengyelt@ainfosec.com>
Cc: Jan Beulich <jbeulich@suse.com>
---
 xen/common/efi/boot.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Jan Beulich Sept. 21, 2017, 1:04 p.m. UTC | #1 
>>> On 20.09.17 at 22:57, <tamas@tklengyel.com> wrote:
> From: Tamas K Lengyel <lengyelt@ainfosec.com>
> 
> The EFI messages flash by so fast that it is impossible to catch them without
> a serial debugger attached. Sometimes though we don't have that available so
> having some time to read the messages off the screen is valuable.
> 
> Signed-off-by: Tamas K Lengyel <lengyelt@ainfosec.com>

NAK: I don't want any unnecessary stalls, including on debug
builds. If you want such stalls for yourself, patch then in as
needed.

Jan
diff mbox

Patch

diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index a3a439b838..1bce148bd9 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -321,6 +321,11 @@  static void __init noreturn blexit(const CHAR16 *str)
         PrintStr((CHAR16 *)str);
     PrintStr(newline);
 
+#ifndef NDEBUG
+    if ( efi_bs )
+        efi_bs->Stall(5000000);
+#endif
+
     if ( !efi_bs )
         efi_arch_halt();
 
@@ -1300,6 +1305,10 @@  efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     if ( gop )
         efi_set_gop_mode(gop, gop_mode);
 
+#ifndef NDEBUG
+    efi_bs->Stall(5000000);
+#endif
+
     efi_exit_boot(ImageHandle, SystemTable);
 
     efi_arch_post_exit_boot();