[U-Boot] Standalone API examples on the P4080DS
David George
dgeorge at rapitasystems.com
Fri Jan 16 12:19:22 CET 2015
Hi all,
I have compiled the hello_world standalone API example documented at
http://www.denx.de/wiki/view/DULG/UBootStandalone for the Freescale
P4080DS development board.
For the standalone api example hello_world, the tutorial (linked above)
states that the entry point of the application *is offset 4 bytes from
the start of the file* (I.E. address 0x40004).
With all build settings at default, my standalone base address is
0x40000 (defined in arch/powerpc/config.mk). This produces the following
object code:
00040000 <hello_world>:
40000: 94 21 ff e0 stwu r1,-32(r1)
40004: 7c 08 02 a6 mflr r0
40008: bf 61 00 0c stmw r27,12(r1)
4000c: 7c 7e 1b 78 mr r30,r3
40010: 7c 83 23 78 mr r3,r4
40014: 90 01 00 24 stw r0,36(r1)
It looks like the entry point is 0x40000. Why does the tutorial state
that the example needs to be run from a 4 byte offset? In this case this
will result in a failure to create a stack frame for hello_world.
Thanks!
Dave George
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