I've built some arm-aout cross compiler tools for Linux and am now attempting a "pre- Hello, World" program: a "write something on the LEDs" program. It doesn't work yet so I thought I'd call upon the collective experience of the mailing list. Here's the code: /* ** The next line is a guess */ typedef unsigned long UINT32; /* ** From BoardSupport/VxWorks/IXP1200EB/ixp1200eb.h */ #define IXP1200_LED_ADDR (0x38400000+0x108000) /* Addr of LED */ #define IXP1200_REG_WRITE(a,val) (*(volatile UINT32 *)(a) = (val)) /* ** From BoardSupport/VxWorks/IXP1200EB/sysLib.c */ #define DEBUG_LED(val) IXP1200_REG_WRITE(IXP1200_LED_ADDR, (val)) void __main(void) { DEBUG_LED(3); loop: goto loop; } I compile it with: arm-aout-gcc -nostartfiles -nodefaultlibs -o led.aout led.c An "arm-aout-objdump --disassemble led.aout" of the resulting file gives this: led.aout: file format a.out-arm-little Disassembly of section .text: 00008000 <___main>: 8000: e1a0c00d mov ip, sp 8004: e92dd800 stmdb sp!, {fp, ip, lr, pc} 8008: e24cb004 sub fp, ip, #4 800c: e3a035e1 mov r3, #943718400 8010: e2833942 add r3, r3, #1081344 8014: e3a02003 mov r2, #3 8018: e5832000 str r2, [r3] 0000801c <L3>: 801c: eafffffe b 801c <L3> 8020: e95ba800 ldmdb fp, {fp, sp, pc}^ ... When I put it in place of the vxWorks boot image and reboot the system I get this: Attached TCP/IP interface to eeE0. Attaching network interface lo0... done. Loading... tftpGet: Error occurred while transferring the file. Error loading file: errno = 0x530001. Can't load boot file!! Early serial debug initialized muxLoad failed! 0x [VxWorks Boot]: There are many things which could be wrong. I'm using little-endian. I'm using the default start address of 0x00008000. I'm using an a.out file. Any suggestions? Anyone know what error 0x530001 means? Thanks, Scott Johnson, Erik J writes:
If the boot loader can load our code directly, this is just what we want. I guess we just need to get the details of the initial boot loader. For example, what is the format of the file it pulls over?
a.out, if I remember the code correctly. After pulling it down, it will jump to the entry point given in the a.out header.
Where in memory is the image placed? (i.e., where do we need to link our text, bss, and data sections.)
there should be MACROs and a routine that determines this in the BSP (BoardSupport/VxWorks/...../sysLib.c) (sorry I don't have the code handy right now, so I might have the names wrong). But look for things of the nature like sysMemTop() and SYS_MEM???. The memory map given in in the HRM might also provide the information.
erik
-Scott
Raghunandan, Makaram writes:
The VxWorks boot image that is on the Flash ROM of IXP1200 Evaluation system does exactly what you need. The initial boot loader comes up initializes the Chip, and, the Ethernet NIC. After that the full suite of VxWorks is pulled over from the network. Now, in your case, you can use this method to load your OS rather than the default file.
Another alternative is to use the Angel Debug Monitor that is also loaded on the FlashROM. The ARM SDT (from ARM LTD.) can be used in conjunction with this to load any program on to the StrongARM core.
-----Original Message----- From: Scott C. Karlin [mailto:scott@CS.Princeton.EDU] Sent: Wednesday, April 19, 2000 8:27 PM To: ixp1200@CS.Princeton.EDU Subject: Meta Boot Loader
We'd like to begin porting our own operating system (Scout) to the StrongARM core of the IXP1200. To do this we'll need a way to get code into the device. We have a couple of thoughts on this and would like to get some feedback (especially from the Intel folks who are on the list). We basically need a way to load a raw image into the core and start running it. We are not using VxWorks or eCOS.
Approaches:
1. Purchase or lease a NetROM device. 2. Use a device programmer to program the flash EEPROM. Is the flash in a socket? The chip packaging looks unfamiliar. 3. Use a Meta Boot Loader. This is code that runs under VxWorks. The preprogrammed boot loader in ROM can load the meta boot loader which will, in turn, load our OS code.
Number 3 has the advantage that it is an all software solution. The problem is that it appears to need a VxWorks executable (the meta boot loader) but we aren't interested in purchasing a license for this one little program. Is this something that someone else has done (or could do)?