From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3DEF754B.8010505@bluewin.ch> Date: Thu, 05 Dec 2002 16:48:27 +0100 From: Wolfgang Grandegger MIME-Version: 1.0 To: Abraham vd Merwe Cc: Linux on PowerPC Developers Mail List Subject: Re: questions about porting an 8240 arch to linux References: <20021205161437.A16705@crystal.2d3d.co.za> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Hello, I recommend to use the linuxppc_devel_2_4 tree for your embedded board (have a look to http://penguinppc.org/dev/kernel.shtml for further information). The configuration and implementation for the Sandpoint board is a good starting point as it's based on a 8240 as well. Another good example might be the implementation for the zx4500. Hope it helps, Wolfgang. On 12/05/2002 03:14 PM Abraham vd Merwe wrote: > Hi! > > !!! Here's what I have: > > * Board based on Motorola MPC8240 processor (based on 603e core) > * 32M sdram > * 250mhz processor > * board is based on PowerPC microprocessor command hardware reference > platform (CHRP). > > !!! Here's what I figured out/did so far. Please correct me if I did > something wrong. > > 1. used 2.4.18 w/ 2.4.18-ppc patch applied (got it from ftp.kernel.org) > 2. added my arch to arch/ppc/config.in > 3. added a embed_config() section to arch/ppc/boot/simple/embed_config.c for > my arch with the following hardcoded parameters: > > ------------< snip <------< snip <------< snip <------------ > bd->bi_intfreq = 250 * 1000000; > bd->bi_busfreq = 33 * 1000000; > bd->bi_memsize = 32 * 1024 * 1024; > bd->bi_baudrate = 9600; > ------------< snip <------< snip <------< snip <------------ > > i have no idea what bus bi_busfreq refers to so I assumed PCI running at > 33mhz. what is this bus frequency? > > 4. add an include for my arch header in include/asm-ppc/mpc8xx.h > 5. defined the following bd_t structure in my arch header: > > ------------< snip <------< snip <------< snip <------------ > typedef struct { > unsigned int bi_intfreq; /* cpu frequency (hz) */ > unsigned int bi_busfreq; /* bus frequency (hz) */ > unsigned int bi_memsize; /* size of memory (bytes) */ > unsigned int bi_baudrate; > } bd_t; > ------------< snip <------< snip <------< snip <------------ > > 6. defined IMAP_ADDR, IMAP_SIZE, NR_8259_INTS in my arch header > > !!! things I still need to figure out or don't have a clue about: > > 1. what is IMAP_ADDR, IMAP_SIZE. I searched for IMMR in the MPC8240 > reference manual and couldn't find anything - I have no idea what IMAP_ADDR > should be and I assumed IMAP_SIZE should be 64k like the other platforms. > > 2. what uart should I use? the user manual claims the board has a 8250 > compatible uart, but if I compile in the standard linux 16550 uart support, > it exports the same symbols as those in arch/ppc/boot/simple/m8xx_tty.c > which is compiled when I select M8XX support. I disabled the 16550 support > for now and defined NR_8259_INTS to 16 (what should this be?) for now just > to get it to compile. > > 3. do I need to setup any registers before branching to the kernel? > > -- > > Regards > Abraham > > It's no use crying over spilt milk -- it only makes it salty for the cat. > > __________________________________________________________ > Abraham vd Merwe - 2d3D, Inc. > > Device Driver Development, Outsourcing, Embedded Systems > > Cell: +27 82 565 4451 Snailmail: > Tel: +27 21 761 7549 Block C, Aintree Park > Fax: +27 21 761 7648 Doncaster Road > Email: abraham@2d3d.co.za Kenilworth, 7700 > Http: http://www.2d3d.com South Africa > > > ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/