From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Fri, 12 Nov 2010 16:53:42 +0100 Subject: Single binary kernel for all i.MX In-Reply-To: References: <20101105121800.GV6017@pengutronix.de> Message-ID: <20101112155342.GJ18358@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Shawn, On Fri, Nov 12, 2010 at 11:40:41PM +0800, Shawn Guo wrote: > I'm studying at the implementation. Can you please help me understand > how "addruart" in plat-mxc/include/mach/debug-macro.S works for single > image? > > .macro addruart, rp, rv > ldr \rp, =UART_PADDR @ physical > ldr \rv, =UART_VADDR @ virtual > .endm > > We have this macro to get physical base address of UART. However > UART_PADDR is defined as MX?_UART1_BASE_ADDR depending on > CONFIG_ARCH_MX*. When all CONFIG_ARCH_MX* get defined in single image > case, how does UART_PADDR work for all CONFIG_ARCH_MX*? In a kernel that supports more than one SoC, DEBUG_LL won't work. This is generally OK, because DEBUG_LL is only needed when bringing up a machine. Therefor you can use a tailored kernel that only supports your shiny new machine. Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |