[U-Boot-Users] printf with u-boot-1.1.2

[Andrew Wozniak]

Andrew Wozniak  |  Mercury Computer Systems
978.967.1895    |  System SW, ICS Group


Shakthi Kannan wrote:
> Greetings!
> 
> I am using u-boot-1.1.2 with CodeSourcery's 3.4.3
> cross-toolchain for ARM on the Versatile PB-ARM926EJ-S
> board.
> 
> u-boot compiles fine. The hello_world.c in examples/
> compiles fine. From the given example, I have removed
> all statements except the printf statement. It
> compiles fine.
> 
> I load it address 04000000 (SDRAM on board, top bank).
> I execute it using "go 04000000", it runs and exits
> with rc=0x0. But, I don't see the printf string being
> printed. Only one character gets printed. I am
> wondering if printf uses \r after every character gets
> printed, so it basically overwrites. 
> 
> I am able to display a character, using putc(). getc()
> also works fine. These work if I load it a SDRAM
> address, say, 0x05000000, and give the entry point as
> 05000000 itself (go 05000000). But, the documentation
> mentions offset 0x4 as entry point.

Why not try running with the offset - works for me.

> I'd appreciate any feedback on what I am doing wrong
> and how I can get the printf working.

Assuming you compiled with -g, take a look at hello_world.o for the 
generated assembly code. See anything obvious?

$ ppc_405-objdump -S hello_world.o

hello_world.o:     file format elf32-powerpc

Disassembly of section .text:

00000000 <hello_world-0x4>:
    0:   00 00 7f e8     .long 0x7fe8

00000004 <hello_world>:

int hello_world(int argc, char *argv[])
{
    4:   94 21 fe 48     stwu    r1,-440(r1)
    8:   7c 08 02 a6     mflr    r0
    c:   be c1 01 90     stmw    r22,400(r1)
   10:   90 01 01 bc     stw     r0,444(r1)
   14:   48 00 00 05     bl      18 <hello_world.c+0x14>
   18:   7f c8 02 a6     mflr    r30
   1c:   80 1e ff e8     lwz     r0,-24(r30)
   20:   7f c0 f2 14     add     r30,r0,r30
     DECLARE_GLOBAL_DATA_PTR;

     bd_t *bd = gd->bd;
   24:   83 9d 00 00     lwz     r28,0(r29)
<snip>

> Thanks,
> 
> SK
> 
> --
> Shakthi Kannan, MS
> Software Engineer, Specsoft (Hexaware Technologies)
> [E]: shakthimaan at yahoo.com           [M]: (91) 98407-87007
> [W]: http://www.shakthimaan.com      [L]: Chennai, India
> 
> 
> 	
> 		
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