[PATCH v2 1/2] ARM: Add cpu_resume_arm() for firmwares that resume in ARM state
From: Uwe Kleine-König <hidden>
Date: 2015-06-15 06:33:38
Also in:
linux-arm-msm, lkml
Hello, On Tue, Jun 02, 2015 at 12:12:57PM -0700, Stephen Boyd wrote:
Some platforms always enter the kernel in the ARM state even if the kernel is compiled for THUMB2. Add a small wrapper on top of cpu_resume() that switches into THUMB2 state. This fixes a problem reported by Kevin Hilman on next-20150601 where the ifc6410 fails to boot a THUMB2 kernel because the platform's firmware always enters the kernel in ARM mode from deep idle states. Reported-by: Kevin Hilman <redacted> Cc: Ard Biesheuvel <redacted> Cc: Lina Iyer <redacted> Signed-off-by: Stephen Boyd <redacted>
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 76bb3128e135..f37593567ef5 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S@@ -118,6 +118,12 @@ ENDPROC(cpu_resume_after_mmu) .text .align + .arm +ENTRY(cpu_resume_arm) + THUMB( badr r9, 1f ) @ Kernel is entered in ARM. + THUMB( bx r9 ) @ If this is a Thumb-2 kernel, + THUMB( .thumb ) @ switch to Thumb now. + THUMB(1: ) ENTRY(cpu_resume) ARM_BE8(setend be) @ ensure we are in BE mode #ifdef CONFIG_ARM_VIRT_EXT
this patch is in next as 51ac91b7f6b11b0da55ac93885ee7b864865bcb1 and breaks efm32_defconfig. The exact error message is: AS arch/arm/kernel/sleep.o arch/arm/kernel/sleep.S: Assembler messages: arch/arm/kernel/sleep.S:121: Error: selected processor does not support ARM opcodes arch/arm/kernel/sleep.S:123: Error: bad instruction `badr r9,1f' arch/arm/kernel/sleep.S:124: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx r9' scripts/Makefile.build:294: recipe for target 'arch/arm/kernel/sleep.o' failed make[3]: *** [arch/arm/kernel/sleep.o] Error 1 Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |