Commit 740a3e67 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: Enable skipping of bss on debug platforms for sh32 also. 



This enables the same functionality that sh64 has for sh32. When running
on simulated hardware or via remote memory via the debug interface,
memory is gauranteed to be zero on boot already, and skipping the zeroing
of BSS has measurable boot time benefits.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 8a655053

arch/sh/Kconfig.debug

+12 −3
Original line number Diff line number Diff line
@@ -98,6 +98,18 @@ config IRQSTACKS 
	  for handling hard and soft interrupts.  This can help avoid

	  overflowing the process kernel stacks.



config SH_NO_BSS_INIT

	bool "Avoid zeroing BSS (to speed-up startup on suitable platforms)"

	depends on DEBUG_KERNEL

	default n

	help

	  If running in painfully slow environments, such as an RTL

	  simulation or from remote memory via SHdebug, where the memory

	  can already be gauranteed to ber zeroed on boot, say Y.



	  For all other cases, say N. If this option seems perplexing, or

	  you aren't sure, say N.



config MORE_COMPILE_OPTIONS

	bool "Add any additional compile options"

	help
@@ -125,9 +137,6 @@ config SH_ALPHANUMERIC 
	bool "Enable debug outputs to on-board alphanumeric display"

	depends on SH_CAYMAN



config SH_NO_BSS_INIT

	bool "Avoid zeroing BSS (to speed-up startup on suitable platforms)"



endif



endmenu

arch/sh/kernel/head_32.S

+10 −2
Original line number Diff line number Diff line
@@ -81,6 +81,12 @@ ENTRY(_stext) 
	ldc	r0, r7_bank	! ... and initial thread_info

#endif



#ifndef CONFIG_SH_NO_BSS_INIT

	/*

	 * Don't clear BSS if running on slow platforms such as an RTL simulation,

	 * remote memory via SHdebug link, etc.  For these the memory can be guaranteed

	 * to be all zero on boot anyway.

	 */

				! Clear BSS area

#ifdef CONFIG_SMP	

	mov.l	3f, r0
@@ -97,6 +103,8 @@ ENTRY(_stext) 
	 mov.l	r0,@-r2



10:		

#endif



	!			Additional CPU initialization

	mov.l	6f, r0

	jsr	@r0

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