# # $Id$ # BSP supporting the on-CPU capabilities of the Synova Mongoose-V. This BSP assumes that basic HW initialization is performed by PMON. Address Map =========== This is the generic address map of the Mongoose-V prototyping board this BSP was tested on. 0x8000_0000 - 0x8FFF_FFFF - RAM (KSEG0 cached) 0xA000_0000 - 0xAFFF_FFFF - RAM (KSEG1, same memory uncached) 0xBFC0_0000 - 0xBFFF_FFFF - EEPROM 0xFFFE_xxxx - on-CPU peripherals This is the hardware address map of the board used as it was actually populated. 0x8000_0000 - 0x83FF_FFFF - 32 MB RAM (KSEG0 cached) 0xA000_0000 - 0xA3FF_FFFF - 32 MB RAM (KSEG1, same memory uncached) 0xBFC0_0000 - 0xBFDF_FFFF - 2 MB EEPROM 0xFFFE_xxxx - on-CPU peripherals This is the organization of the EEPROM when fully populated. Since the board used to develop this BSP only had the first bank of EEPROM populated, only the first program image area was used. 0xBFC0_0000 - 0xBFC3_FFFF - PMON 0xBFC4_0000 - 0xBFC4_FFFF - reserved for boot loader 0xBFC5_0000 - 0xBFDF_FFFF - reserved for program 1 image 0xBFE0_0000 - 0xBFFF_FFFF - reserved for program 2 image The Mongoose-V on this board is at 12 Mhz. Downloading =========== On the breadboard, a locally hacked PMON waits for a space to be pressed while the board is reset/powered up. If found, the PMON console is entered, else PMON jumps to the EEPROM address above, presuming a user program is located there. The default output of an RTEMS link is an image linked to run from 80020000, but has had its LMA shifted up to BFC40000. It is suitable for copying to S3 records or can be burned to ROMs in whatever manner the user desires. Operation ========= A small relocator is supplied in the bsp startup code which copies the image down to RAM for execution before doing any other initialization. This locator code is location independent, and will do nothing if the image is already located at its run location. The LMA and VMA are both controlled via the bsp's link script. The above behavior is produced by using the default script. If this is not desirable, something like the following may be added to the user's RTEMS link statement to override the default linkcmds with a user-supplied version; -qnolinkcmds -Wl,-T -Wl,mips-rtems-linkcmds-eprom this causes the file ./mips-rtems-linkcmds-eprom to override the default linkcmds. Before relocating the RTEMS image, the bsp startup routine attempts to configure the processor into a rational state. During this process, status characters are emitted at 19200N81 baud on UART port 0. Questions ========= Why can I send characters slowly to a Mongoose V, but get framing errors when sending them fast? - The MongooseV chip seems to that all incoming data have 2 stop bits. When typing on a serial terminal, this is not an issue because the idle state of an RS232 line looks just like a stop bit- but when streaming in data, such pacing is required. The manual does not indicate anything along these lines, instead, we suspect a somewhat faulty UART design. Status ======