[Qemu-devel] ARM bootloader boot blobbing.

[Peter Crosthwaite]

Hi All,

Can anyone think of a reason why the arm primary bootloader cant be
done by just direct interaction with the CPU? Currently we have this
...

/* The worlds second smallest bootloader.  Set r0-r2, then jump to kernel.  */
static uint32_t bootloader[] = {
  0xe3a00000, /* mov     r0, #0 */
  0xe59f1004, /* ldr     r1, [pc, #4] */
  0xe59f2004, /* ldr     r2, [pc, #4] */
  0xe59ff004, /* ldr     pc, [pc, #4] */
  0, /* Board ID */
  0, /* Address of kernel args.  Set by integratorcp_init.  */
  0  /* Kernel entry point.  Set by integratorcp_init.  */
};

... which gets injected into RAM then we set the PC to this blob and
go. But couldnt we just set R0-2 directly from the bootloader and just
straight to the kernel entry point? Why do we have to blob in a
lightweight bootloader?

Regards,
Peter