From 97f0b07fac37102088a3ac4ba1eb995472a1335c Mon Sep 17 00:00:00 2001 From: Lee Leahy Date: Wed, 8 Jun 2016 13:40:08 -0700 Subject: [PATCH] UPSTREAM: arch/x86: Add debug spinloops in assembly_entry.S Use Kconfig values to enable debug spinloops in assembly_entry.S. This makes it easy to debug the assembly code. TEST=Build and run on Galileo Gen2 BUG=None BRANCH=None TEST=None Change-Id: Ic56bf2260b8e3181403623961874c9289f3ca945 Original-Signed-off-by: Lee Leahy Original-Reviewed-on: https://review.coreboot.org/15135 Original-Tested-by: build bot (Jenkins) Original-Reviewed-by: Paul Menzel Original-Reviewed-by: Aaron Durbin Signed-off-by: Aaron Durbin Reviewed-on: https://chromium-review.googlesource.com/351785 Commit-Ready: Furquan Shaikh Tested-by: Furquan Shaikh Reviewed-by: Furquan Shaikh --- src/arch/x86/Kconfig | 14 ++++++++++++++ src/arch/x86/assembly_entry.S | 11 +++++++++++ 2 files changed, 25 insertions(+) diff --git a/src/arch/x86/Kconfig b/src/arch/x86/Kconfig index 8609e20136..1fea99ac3b 100644 --- a/src/arch/x86/Kconfig +++ b/src/arch/x86/Kconfig @@ -179,3 +179,17 @@ config VERSTAGE_ADDR # from a program loaded in ram and subsequently loading ramstage. config POSTCAR_STAGE def_bool n + +config VERSTAGE_DEBUG_SPINLOOP + bool + default n + help + Add a spin (JMP .) in assembly_entry.S during early verstage to wait + for a JTAG debugger to break into the execution sequence. + +config ROMSTAGE_DEBUG_SPINLOOP + bool + default n + help + Add a spin (JMP .) in assembly_entry.S during early romstage to wait + for a JTAG debugger to break into the execution sequence. diff --git a/src/arch/x86/assembly_entry.S b/src/arch/x86/assembly_entry.S index 86dbba4668..d1f5d61ce7 100644 --- a/src/arch/x86/assembly_entry.S +++ b/src/arch/x86/assembly_entry.S @@ -52,6 +52,17 @@ _start: sub %edi, %ecx rep stosl +#if ((ENV_VERSTAGE && IS_ENABLED(CONFIG_VERSTAGE_DEBUG_SPINLOOP)) \ + || (ENV_ROMSTAGE && IS_ENABLED(CONFIG_ROMSTAGE_DEBUG_SPINLOOP))) + + /* Wait for a JTAG debugger to break in and set EBX non-zero */ + xor %ebx, %ebx + +debug_spinloop: + cmp $0, %ebx + jz debug_spinloop +#endif + jmp car_stage_entry /* This is here for linking purposes. */