there is a strange problem.
my platform is ml410, port linux-2.6.23rc2 vertex kernel to it. the toolchain
is generated by crosstool. the cross-gcc is powerpc-405-linux-gnu-gcc
4.0.2.when i complete the kernel compiling and download it to the board to run,
there are a few questions.
at first, i can't see anything output after "Now booting the kernel". through
debugging i found that init_IRQ() function in init/main.c can't run to the end.
so i cut it and rerun the kernel. it runs so long until the rootfs is mounted.
the problem occurs in executing /linuxrc. it says "init has generated signal 4
but has no handler for it". the reason, i've known, is that i disabled the
init_IRQ() function. then i get down to search for the wrong point.
the init_IRQ() called in init/main.c is defined in arch/powerpc/kernel/irq.c.
init_IRQ() calls ppc_md.init_IRQ(). ppc_md is a variable of "struct
machdep_calls". the ppc_md.init_IRQ is evaluated in
arch/ppc/syslib/ppc4xx_setup.c. the statement is ppc_md.init_IRQ =
ppc4xx_init_IRQ. and the ppc4xx_init_IRQ() calls ppc4xx_pic_init() defined in
arch/ppc/syslib/xilinx_pic.c.
tracing into ppc4xx_pic_init() function, i located the problem at
"intc_out_be32(intc + IER, 0)". "intc_out_be32" is a macro as the real form
"out_be32((addr), (mask))". the out_be32() is a function defined in
include/asm-ppc/io.h.
extern inline void out_be32(volatile unsigned __iomem *addr, int val)
{
__asm__ __volatile__("sync; stw%U0%X0 %1,%0" : "=m" (*addr) : "r"
(val));
}
i replace "intc_out_be32(intc + IER, 0)" with the assemble statements and
rerun, nothing changes.
XPS's debugger points out that the kernel stop in _delay() function. but there
is not any call to this function. only the 2 assemble statements are there.
dividing the "sync" and "stw" into 2 __asm__ ones, "sync" is passed but "stw"
makes a strange _delay() calling.
so strange it is, who can help me?
thanks.
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