< $(OBJCOPY) -O binary $< $@ 2>/dev/null
$(OBJCOPY) -O ppcboot $< $@ 2>/dev/nullPlease explain why. Does the MontaVista version of the binutils doe not understand "binary" output format any longer?
The MontaVista tools will not convert binary to srec. You get an error message about unknown architecture. However I discovered the ppcboot
options
which works fine. Another solution is to use "dd" to strip the 64k
header.
Well, this is a bug in the MV toolchain then. Complain at MV. We will NOT add this to the Makefile as it breaks all other systems.
My suggestion was to add this as a comment to the Makefile.
Index: board/mpc8266ads/config.mk
RCS file: /cvsroot/u-boot/u-boot/board/mpc8266ads/config.mk,v retrieving revision 1.2 diff -r1.2 config.mk 30c30
< TEXT_BASE = 0xfe000000
TEXT_BASE = 0xfff00000
Please explain why you think this is necessary.
The reset vector for 8260 is 0xfff00100. The easiest way to u-boot to put code at this location is to change TEXT_BASE. This is the same as the MPC8260 config.mk file....
There is no relation between the reset vector and TEXT_BASE. You can have the reset vector at 0x100 and TEXT_BASE - say - at 0x40000000. I don't think I want to change this configuration (which seems to be working to several people) without a really good reason.
The reset address is either 0x00000100 or 0xfff00100. The current u-boot configuration doesn't locate any code at these locations. The MPC8260 configuration specified TEXT_BASE as 0xfff00000 and it works. The current u-boot configuration does not boot.
FLASH_BASE 0xff800000 - the board ships with a 8MB SIMM. This is the base address.
You can map the flash at any arbitrary address. I don't see why 0xFF800000 would be any better than 0xFE000000 - on contrary - mapping it at 0xFE000000 leaves enough room if there should ever be a board with bigger flash chips.
As long as something responds to the 0xfff00xxx address range you are correct.
CFG_BCSR & CFG_PCI_INIT - according to the memory map in the MPC8266ADS manual, these are the physical addresses. You need to access the BCSR to enable the serial and Ethernet ports.
Physical addresses on a 82xx are programmable. The programming of the memory controller decides where a device shows up in the physiacal memory map. Please ignore the memory map given in the manyal - it is just one example out of many possible, and it is an example which will NOT work with Linux.
If the only hardware requirement is chip-select generation, this is correct. It would be better to move these to another location.
Actually I think it is a bug to map the BCSR at a low address like 0x04500000. Are you really, really sure that this will work with Linux?
Virtual address != Physical address These are correct according to the documentation
You are wrong. There are certain address ranges in Linux which are mapped with virtual"physical 1:1. The IMMR and BCSR areas are among them.
This is very implementation specific. There have been several discussions about the use of BATs with these architectures.
This works. The current u-boot implementation does not work. Perhaps the current configuration works with a different board configuration. If that
is
true, then there should be a big note somewhere with detailed
configuration
notes.
I doubt that you have any Linux applications running with your configuration.
I see Linux and u-boot as two very different things. In my opinion it is useful to have the BIOS follow the documented configuration. This helps the person who is trying to bring up, and probably learn, a new platform. As they become comfortable with the hardware they can deviate from the standard configuration. The difference is that they made those changes and didn't need to refer to several documents (or source code) to figure out a memory map. When Linux boots, it assumes the BIOS is brain-dead and reconfigures everything. The BCSR and IMMR will be relocated to what makes sense for that operating environment.