From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Fri, 27 Jun 2025 21:05:37 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uVEOH-00BiWl-2m for lore@lore.pengutronix.de; Fri, 27 Jun 2025 21:05:37 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uVEOG-0006u8-S9 for lore@pengutronix.de; Fri, 27 Jun 2025 21:05:37 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=0N6gAwRx2w0hZ8mpDTYcNTg7khV8RhKElUI1t4UKjg0=; b=G4la1HxzzsaOqit40elT4tFBwa Iv+POKje/Bl637AtlOi8VZve+JXINa6w2iwk9rkGppi8xvrH0NwgiPm3/mHXx/JroDS4MHxENjum2 WUja3/p0pgV4HfHzkuG57QVOp1xOkFvBY0vfA5P8NZ8UfpFpLzvC6S9u0sTLPE6ULsfC95ZjmK32v u8Vc91xxkg/eckskArCeK1/L5erL4grkTxwq3zUEXnHZZX5Y4Ykwh8Gk/VKbvt0+06FRMEfm6ktDa rL5mT1G7IdD8rWHyY6283TuzhJGCJT/aYFSwkGxeUE1irKTNIWY7mDbQv1Cp/UShJnqx3WspfwJde jtLLBgKg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uVENk-0000000FZHA-152D; Fri, 27 Jun 2025 19:05:04 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uVD9T-0000000FRPL-0rQm for barebox@lists.infradead.org; Fri, 27 Jun 2025 17:46:16 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1uVD9R-0007Zu-U7; Fri, 27 Jun 2025 19:46:13 +0200 Received: from pty.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::c5]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uVD9R-005ecS-2P; Fri, 27 Jun 2025 19:46:13 +0200 Received: from mfe by pty.whiteo.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1uVD9R-003f0W-24; Fri, 27 Jun 2025 19:46:13 +0200 Date: Fri, 27 Jun 2025 19:46:13 +0200 From: Marco Felsch To: Sascha Hauer Cc: BAREBOX Message-ID: <20250627174613.o7kbuzpciwknizjm@pengutronix.de> References: <20250627-arm-optee-early-helper-v1-0-4b098e8ac7cd@pengutronix.de> <20250627-arm-optee-early-helper-v1-3-4b098e8ac7cd@pengutronix.de> <20250627154509.m2ovsgqdnpoc3auh@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250627_104615_398161_D1202772 X-CRM114-Status: GOOD ( 45.33 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.3 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 03/14] ARM: add exception handling support for PBL X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) On 25-06-27, Sascha Hauer wrote: > On Fri, Jun 27, 2025 at 05:45:09PM +0200, Marco Felsch wrote: > > Hi Sascha, > > > > On 25-06-27, Sascha Hauer wrote: > > > Exception handling in PBL can be very useful for debugging PBL code. > > > This patch adds support for it. > > > > > > This is currently only implemented for ARMv7 and ARMv8. Only on these > > > architectures we can tell the CPU where the exception table is. On ARMv6 > > > and older we would have to copy the exception table either to 0x0 or > > > 0xffff0000. Not all SoCs have writable memory at these locations, so we > > > would have to utilize the MMU to map writable memory there. We are not > > > there yet, so for now skip exception handling support on these older > > > architectures. > > > > > > Signed-off-by: Sascha Hauer > > > --- > > > arch/arm/Kconfig | 10 ++++++++++ > > > arch/arm/cpu/Makefile | 1 + > > > arch/arm/cpu/interrupts_32.c | 14 +++++++++++++- > > > arch/arm/cpu/interrupts_64.c | 10 +++++++++- > > > arch/arm/cpu/uncompress.c | 2 ++ > > > arch/arm/include/asm/barebox-arm.h | 8 ++++++++ > > > arch/arm/lib/pbl.lds.S | 4 ++++ > > > 7 files changed, 47 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > > index 0800b15d784ca0ab975cf7ceb2f7b47ed10643b1..eaccee9f2f7a128a820e1c55fba816ec5ac4c02d 100644 > > > --- a/arch/arm/Kconfig > > > +++ b/arch/arm/Kconfig > > > @@ -378,6 +378,16 @@ config ARM_EXCEPTIONS > > > bool "enable arm exception handling support" > > > default y > > > > > > +config ARM_EXCEPTIONS_PBL > > > + select ARCH_HAS_DATA_ABORT_MASK_PBL > > > + depends on CPU_V7 || CPU_V8 > > > + bool "enable arm exception handling support in PBL" > > > + help > > > + Say yes here to enable exception handling in PBL. Note that the exception > > > + table has to be initialized by calling arm_pbl_init_exceptions(). This is > > > + done in barebox_pbl_start(). If you need exception handling earlier then > > > + you have to call arm_pbl_init_exceptions() earlier from your board code. > > > + > > > config ARM_UNWIND > > > bool "enable stack unwinding support" > > > depends on AEABI > > > diff --git a/arch/arm/cpu/Makefile b/arch/arm/cpu/Makefile > > > index 39e59c2a2f733d668d57a2f28bdd99f69a016229..9550592796702759f950a3bc4de385100ef2b2e8 100644 > > > --- a/arch/arm/cpu/Makefile > > > +++ b/arch/arm/cpu/Makefile > > > @@ -3,6 +3,7 @@ > > > obj-pbl-y += cpu.o > > > > > > obj-$(CONFIG_ARM_EXCEPTIONS) += exceptions_$(S64_32).o interrupts_$(S64_32).o > > > +pbl-$(CONFIG_ARM_EXCEPTIONS_PBL) += exceptions_$(S64_32).o interrupts_$(S64_32).o > > > obj-$(CONFIG_MMU) += mmu-common.o > > > obj-pbl-$(CONFIG_MMU) += mmu_$(S64_32).o > > > obj-$(CONFIG_MMU) += dma_$(S64_32).o > > > diff --git a/arch/arm/cpu/interrupts_32.c b/arch/arm/cpu/interrupts_32.c > > > index 623efb3966f0c34632e678d9e1edf2b6affcb4c5..cd503b38eeea551f27bbab0663bbfabdda7ffeea 100644 > > > --- a/arch/arm/cpu/interrupts_32.c > > > +++ b/arch/arm/cpu/interrupts_32.c > > > @@ -12,6 +12,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > #include > > > > > > /* Avoid missing prototype warning, called from assembly */ > > > @@ -61,7 +62,7 @@ void show_regs (struct pt_regs *regs) > > > fast_interrupts_enabled (regs) ? "on" : "off", > > > processor_modes[processor_mode (regs)], > > > thumb_mode (regs) ? " (T)" : ""); > > > -#ifdef CONFIG_ARM_UNWIND > > > +#if defined CONFIG_ARM_UNWIND && IN_PROPER > > > unwind_backtrace(regs); > > > #endif > > > } > > > @@ -181,3 +182,14 @@ int data_abort_unmask(void) > > > > > > return arm_data_abort_occurred != 0; > > > } > > > + > > > +#if IS_ENABLED(CONFIG_ARM_EXCEPTIONS_PBL) > > > +void arm_pbl_init_exceptions(void) > > > +{ > > > + if (cpu_architecture() < CPU_ARCH_ARMv7) > > > + return; > > > + > > > + set_vbar((unsigned long)__exceptions_start); > > > + arm_fixup_vectors(); > > > +} > > > +#endif > > > diff --git a/arch/arm/cpu/interrupts_64.c b/arch/arm/cpu/interrupts_64.c > > > index 4d4ef2bab88ef46a7be1cd4add8f3e51423a283b..574ab6a7ec220d2239b6e27c05426e2d4c67d426 100644 > > > --- a/arch/arm/cpu/interrupts_64.c > > > +++ b/arch/arm/cpu/interrupts_64.c > > > @@ -88,7 +88,8 @@ static void __noreturn do_exception(struct pt_regs *pt_regs) > > > { > > > show_regs(pt_regs); > > > > > > - unwind_backtrace(pt_regs); > > > + if (IN_PROPER) > > > + unwind_backtrace(pt_regs); > > > > > > panic_no_stacktrace("panic: unhandled exception"); > > > } > > > @@ -226,3 +227,10 @@ static int aarch64_init_vectors(void) > > > return 0; > > > } > > > core_initcall(aarch64_init_vectors); > > > + > > > +#if IS_ENABLED(CONFIG_ARM_EXCEPTIONS_PBL) > > > +void arm_pbl_init_exceptions(void) > > > +{ > > > + aarch64_init_vectors(); > > > +} > > > +#endif > > > diff --git a/arch/arm/cpu/uncompress.c b/arch/arm/cpu/uncompress.c > > > index 4657a4828e67e1b0acfa9dec3aef33bc4c525468..4529ef5e3821e5b31a3673de6285d2f37e0ecba2 100644 > > > --- a/arch/arm/cpu/uncompress.c > > > +++ b/arch/arm/cpu/uncompress.c > > > @@ -63,6 +63,8 @@ void __noreturn barebox_pbl_start(unsigned long membase, unsigned long memsize, > > > > > > pr_debug("memory at 0x%08lx, size 0x%08lx\n", membase, memsize); > > > > > > + arm_pbl_init_exceptions(); > > > + > > > if (IS_ENABLED(CONFIG_MMU)) > > > mmu_early_enable(membase, memsize); > > > else if (IS_ENABLED(CONFIG_ARMV7R_MPU)) > > > diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h > > > index 7d35e88c812393d45e331f238baecfa91cbbe299..3ab442bd373e50a84b26145395e42879fc96757f 100644 > > > --- a/arch/arm/include/asm/barebox-arm.h > > > +++ b/arch/arm/include/asm/barebox-arm.h > > > @@ -52,6 +52,14 @@ static inline void arm_fixup_vectors(void) > > > } > > > #endif > > > > > > +#if IS_ENABLED(CONFIG_ARM_EXCEPTIONS_PBL) > > > +void arm_pbl_init_exceptions(void); > > > +#else > > > +static inline void arm_pbl_init_exceptions(void) > > > +{ > > > +} > > > +#endif > > > + > > > void *barebox_arm_boot_dtb(void); > > > > > > /* > > > diff --git a/arch/arm/lib/pbl.lds.S b/arch/arm/lib/pbl.lds.S > > > index dad37c9e9bca98beb4f34360fa53a0421662f03c..9c51f5eb3a3d8256752a78e03fed851c84d92edb 100644 > > > --- a/arch/arm/lib/pbl.lds.S > > > +++ b/arch/arm/lib/pbl.lds.S > > > @@ -52,6 +52,10 @@ SECTIONS > > > __bare_init_start = .; > > > *(.text_bare_init*) > > > __bare_init_end = .; > > > + . = ALIGN(0x20); > > > + __exceptions_start = .; > > > + KEEP(*(.text_exceptions*)) > > > + __exceptions_stop = .; > > > > Nit: We only need this in case of CONFIG_CPU_64, right? > > s/CONFIG_CPU_64/CONFIG_CPU_32/ > > Yes, right. right /o\ > > Maybe I > > overlooked it but the only user of this section is > > arch/arm/cpu/exceptions_32.S. Not sure why arch/arm/lib64/barebox.lds.S > > has this section too. > > Likely because the initial arm64 linker script started as a copy from > the arm32 linker script. Yes, I guess so too. > I'll prepare a patch to remove the section from arch/arm/lib64/barebox.lds.S > because it's indeed unused. > > In arch/arm/lib/pbl.lds.S we could add an #ifdef CONFIG_CPU_64 around the #ifdef CONFIG_CPU_32. yes. > section, but it doesn't make a difference, the section will be empty > anyway. Sure, just the ALIGN() may add some more bytes but this can be ignored. At least a comment would be nice :) Regards, Marco > > Sascha > > -- > Pengutronix e.K. | | > Steuerwalder Str. 21 | http://www.pengutronix.de/ | > 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | >