From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 4 Jul 2012 16:01:15 +0100 Subject: [PATCH 1/2] ARM: vexpress: add debug UARTs to DEBUG_LL kconfig choice Message-ID: <1341414076-20895-1-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Jonathan Austin The current vexpress code attempts to autodetect the debug UART based on some fragile probing of the memory map. If this fails, we may take an abort attempting to access a device that doesn't exist. This patch avoids probing the various possible UART locations on the different Versatile Express motherboards and instead adds entries into the DEBUG_LL kconfig choice for the two possible memory maps. Signed-off-by: Jonathan Austin Signed-off-by: Will Deacon --- arch/arm/Kconfig.debug | 16 ++++++++++ arch/arm/mach-vexpress/include/mach/debug-macro.S | 34 ++++++++------------- 2 files changed, 29 insertions(+), 21 deletions(-) diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 01a1341..b343f60 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -345,6 +345,22 @@ choice For more details about semihosting, please see chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd. + config DEBUG_VEXPRESS_CA9X4_UART + bool "Kernel low-level debugging messages via CA9X4 UART" + depends on ARCH_VEXPRESS_CA9X4 + help + Say Y here if you want the debug print routines to direct + their output to UART0 of the Versatile Express motherboards + that pre-date the RS1 memory map. + + config DEBUG_VEXPRESS_RS1_UART + bool "Kernel low-level debugging messages via RS1 UART" + depends on ARCH_VEXPRESS_DT + help + Say Y here if you want the debug print routines to direct + their output to UART0 of the Versatile Express motherboards + with the RS1 memory map. + endchoice config EARLY_PRINTK diff --git a/arch/arm/mach-vexpress/include/mach/debug-macro.S b/arch/arm/mach-vexpress/include/mach/debug-macro.S index fa82247..f25a024 100644 --- a/arch/arm/mach-vexpress/include/mach/debug-macro.S +++ b/arch/arm/mach-vexpress/include/mach/debug-macro.S @@ -10,34 +10,26 @@ * published by the Free Software Foundation. */ +#ifdef CONFIG_DEBUG_VEXPRESS_CA9X4_UART #define DEBUG_LL_PHYS_BASE 0x10000000 #define DEBUG_LL_UART_OFFSET 0x00009000 +#endif -#define DEBUG_LL_PHYS_BASE_RS1 0x1c000000 -#define DEBUG_LL_UART_OFFSET_RS1 0x00090000 +#ifdef CONFIG_DEBUG_VEXPRESS_RS1_UART +#define DEBUG_LL_PHYS_BASE 0x1c000000 +#define DEBUG_LL_UART_OFFSET 0x00090000 +#endif #define DEBUG_LL_VIRT_BASE 0xf8000000 - .macro addruart,rp,rv,tmp - - @ Make an educated guess regarding the memory map: - @ - the original A9 core tile, which has MPCore peripherals - @ located at 0x1e000000, should use UART at 0x10009000 - @ - all other (RS1 complaint) tiles use UART mapped - @ at 0x1c090000 - mrc p15, 4, \tmp, c15, c0, 0 - cmp \tmp, #0x1e000000 - - @ Original memory map - moveq \rp, #DEBUG_LL_UART_OFFSET - orreq \rv, \rp, #DEBUG_LL_VIRT_BASE - orreq \rp, \rp, #DEBUG_LL_PHYS_BASE - - @ RS1 memory map - movne \rp, #DEBUG_LL_UART_OFFSET_RS1 - orrne \rv, \rp, #DEBUG_LL_VIRT_BASE - orrne \rp, \rp, #DEBUG_LL_PHYS_BASE_RS1 +#ifndef DEBUG_LL_UART_OFFSET +#error "Unknown vexpress UART offset" +#endif + .macro addruart,rp,rv,tmp + mov \rp, #DEBUG_LL_UART_OFFSET + orr \rv, \rp, #DEBUG_LL_VIRT_BASE + orr \rp, \rp, #DEBUG_LL_PHYS_BASE .endm #include -- 1.7.4.1