> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:linuxppc-embedded- > [EMAIL PROTECTED] On Behalf Of mojtaba > Sent: Friday, May 16, 2008 4:58 AM > To: [email protected] > Subject: Booting Linux from an ACE File > > Dear all, > > Could you please explain what happens exactly when Linux is booting from a > compact flash?
The systemAce file is essentially a script of JTAG commands, some of which target the FPGA with configuration data and some target the PowerPC/microblaze with memory write commands. > To my few knowledge, the Linux compressed image will be copied somewhere in > memory, will be uncompressed and the control will jump to the beginning > address of the Linux kernel. > > Is there any boot loader that copies the Linux compressed image to the > memory? Essentially SystemAce does this for you and jumps to the Linux bootwrapper code which begins decompressing the kernel. > Where in memory does it put the Linux kernel? For example, if I have 2 DDRs > in my hardware, in which of them it will be put the kernel? The kernel is compiled at a particular address, typically targetting whatever memory is low in the system. I believe the default target address is 0x40000. So whatever DDR memory lives at this address will be targetted. > Can I set the kernel location in memory manually? If you change how the bootwrapper code and linker script work, yes. > Might be an stupid question but: Is it possible for the kernel to be half in > BRAMS and half in DDR? There have been some recent patches on the microblaze mailing lists that attempt to put some of the latency-critical code (exception handlers and the like) in BRAM. Doing this is likely pretty architecture specific, since you probably have a particular goal in mind. Steve This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately. _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
