From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerry Van Baren Date: Wed, 26 Sep 2007 08:25:01 -0400 Subject: [U-Boot-Users] U-BOOT and UART TX with interrupts (need help please) In-Reply-To: <12897695.post@talk.nabble.com> References: <12896654.post@talk.nabble.com> <20070926090439.51AE22405D@gemini.denx.de> <12897695.post@talk.nabble.com> Message-ID: <46FA4F9D.30803@smiths-aerospace.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de veter wrote: > wd wrote: >> In message <12896654.post@talk.nabble.com> you wrote: >>> Our program based on U-BOOT and we need transmit data at UART-TX with >>> interrupts. >> What makes you think you need interrupts? U-Boot is strictly single >> tasking, so it will not do anything else anyway while transmitting, >> and even a very slow CPU should be capable of streaming characters >> out or an UART then. >> >>> But, as we understand, U-BOOT do not have "API" for correct realization >>> Interrupts, we fount in cpu/bf532/serial.c each initialization with as-be >>> usage Interrupts, but not used it, because only doing looping ISR >>> register >>> on FLAG IRQ_UART_TX_BIT. >> Indeed polling is all you need. >> >>> It is not correct usage Interrupts. We need full usage interrupts. >> What makes you think so? Interrupts will not give you any advantages. >> >> Best regards, >> >> Wolfgang Denk > > I greet you! > It is hope for your help! > > The fact is that we have decided to base / Platform U-BOOT make its program > to develop so it is ready realizovanno many software tools. > > Interruption we need to make our CPU BlackFin we can use with DMA capability > and maximize productivity gains. > > Core, we want to use and abandonment of the CPU and DMA (BlackFin 532). > In fact, we will have passed a very big massyvy in UART and use DMA, we will > win big, because 90% of CPU performance will be employed mathematical > calculations. > > For that reason has much to use the lack of interruption, please help! Please don't top post. U-Boot is a boot loader, used to * Initialize the hardware * Load an operating system * Start the operating system running You are looking for an operating system with interrupts and possibly multi-tasking. U-Boot may be helpful in *loading and starting* your operating system, but it is *not* an operating system. It does not normally use, and thus has no support for, interrupts. Best regards, gvb