Hi Daniel, I just looked in my .config file. There is nothing about CP15, and you're right, my processor does not have such a coprocessor. Concerning the Architecture ID: 0x41007700 is for ARM7/710 according to the comments in head.S, but there is also 0x00020000, which is ARMv4T, which should also do the job, shouldn't it?
Anyway, with none of these, my kernel is able to boot. I have tried two variants: one without the "Compressed ROM bootloader" optiion. With this, the zImage must be copied to SDRAM and be executed there. This did not work, as well as with the "Compressed ROM bootloader" option, which should allow zImage to run from Flash. It also does not matter whether my Architecture ID is 0x41007700 or 0x00020000. The worst thing is, that I'm unable to debug this code. I tried it with some JTAG - GDB Adaptor and then tried to connect with ddd, but it cannot match the debug symbols with the addresses, for me it looks like the code is being executed from another address whether it is liked to. But I have set these Parameters: CONFIG_DRAM_BASE=0xa0000000 CONFIG_DRAM_SIZE=0x03000000 CONFIG_FLASH_MEM_BASE=0x80000000 CONFIG_FLASH_SIZE=0x00400000 So what I did so far is to just step trough the plain assembly code, without any debug symbols, and you can imagine, it's very difficult to get an idea what this thing is doing :-) Basically, I think NOMMU should work with the standard Linux kernel, as well as the ARM7TDMI variant. Or am I wrong and I need some special branch or patch or something? I don't think so, because there are options in the menuconfig for NOMMU and ARM7TDMI, and that's why I'm a bit confused, I expected it at least to decompress and boot properly until it comes to some machine-specific initialisations (which reside in arch/arm/mach-* directory). Tobias ________________________________________ Von: uclinux-dev-boun...@uclinux.org [uclinux-dev-boun...@uclinux.org]" im Auftrag von "Daniel Glöckner [daniel...@gmx.net] Gesendet: Samstag, 27. Juli 2013 18:26 An: uClinux development list Betreff: Re: [uClinux-dev] ARM7TDMI zImage booting Hi Tobias, On Sat, Jul 27, 2013 at 02:53:07PM +0000, Plüss Tobias TA.E.1001 wrote: > >> CONFIG_PROCESSOR_ID > > MANY THANKS for this tip! I have never analysed what this processor ID is > used for; i always thought that it is just some arbitrary number to verify > that the kernel is running on the right hardware. So I left it always at > the default value, which is 0x41007700. But, now I searched in the head.S > file for this number, and you we're right - it seems like this is the > processor ID for ARM7/710, which is definitely wrong. I'll try this > evening to change the CONFIG_PROCESSOR_ID to 0x00020000, which should be > ARMv4T - which is exactly what I want. I'll tell you whether I'm > successful ;-) 0x41007700 won't lead to clz, though, and ARM7/710 doesn't sound wrong for an ARM7TDMI. If the support for other processors is still enabled, head.S will ask CP15 for the ID. A plain ARM7TDMI doesn't have that coprocessor and will most likey generate an exception. Do you have CONFIG_CPU_CP15=y in your .config? Daniel _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
