- Question:
- I am using U-Boot with a Linux kernel version
Y (Y < 2.4.5-pre5), but the last message I see is
Uncompressing Kernel Image ... OK
Then the system hangs.
- Answer:
- Most probably you pass bad parameters to the Linux kernel.
There are several possible reasons:
- Bad definition of the
bd_info structure
You must make sure that your machine specific header file
(for instance include/asm-ppc/tqm8xx.h)
includes the same definition of the Board Information
structure as we define in
include/ppcboot.h, and make sure that
your definition of IMAP_ADDR uses the same
value as your U-Boot configuration in
CFG_IMMR.
- Bad clock information
Before kernel version 2.4.5-pre5 (BitKeeper Patch 1.1.1.6,
22MAY2001) the kernel expected the clock information in MHz,
but recent kernels expect it in Hz instead. U-Boot passes
the clock information in Hz by default.
To switch to the old behaviour, you can set the
environment variable "clocks_in_mhz" in U-Boot:
=> setenv clocks_in_mhz 1
=> saveenv
For recent kernel the
"clocks_in_mhz" variable
must not be set.
If it is present in your environment, you can delete it as follows:
=> setenv clocks_in_mhz
=> saveenv
A common error is to try
"setenv clocks_in_mhz 0" or to some other value - this
will not work,
as
the value of the variable is not important at all.
It is the
existence of the variable that will be checked.
-
- Inconsistent memory map
Some boards may need corrct mappings for some special hardware devices like
BCSR (Board Control and Status Registers) etc.
Verify that the mappings expected by Linux match those created by U-Boot.
