Adding Support for Aruba AP135

For Developers
10

What I've run up against so far in porting the AP-135 is that:

  • kwboot does not work
  • there's no bootm
  • we could use go as we've done with the AP105/AP175, however ...
    • compiling a raw zImage to boot here gives me a data abort, with $PC set 2 words / 8 bytes after the first branch. Truncating the zImage to right after that first branch still creates the same error, whereas truncating it one word more removes it -- thus I'm forced to assume the error is caused by the branch itself, which would seem to suggest that we're not allowed to run the 'b' instruction somehow.

Here's the rasm2 output of the zImage:

# rasm2 -D -B -a arm -b 32 -c arm -f zImage
0x00000000   4                 0000a0e1  mov r0, r0
0x00000004   4                 0000a0e1  mov r0, r0
0x00000008   4                 0000a0e1  mov r0, r0
0x0000000c   4                 0000a0e1  mov r0, r0
0x00000010   4                 0000a0e1  mov r0, r0
0x00000014   4                 0000a0e1  mov r0, r0
0x00000018   4                 0000a0e1  mov r0, r0
0x0000001c   4                 0000a0e1  mov r0, r0
0x00000020   4                 050000ea  b 0x3c
0x00000024   4                 18286f01  invalid
0x00000028   4                 00000000  andeq r0, r0, r0
0x0000002c   4                 f8bb4700  strdeq fp, ip, [r7], -0xb8

.... this corresponding to arch/arm/boot/compressed/head.S's .start section, of course.

The zImage causing this crash is available here: https://downloads.laboratoryb.org/ap135/openwrt-avanta-generic-aruba_ap-135-initramfs-uImage (disregard the name: it's a zImage)