Request for Review: improving Ubldr syscall linkage.

[Warner Losh]

On May 1, 2012, at 10:55 AM, Ian Lepore wrote:

> On Tue, 2012-05-01 at 10:23 -0600, Warner Losh wrote:
>> On May 1, 2012, at 2:01 AM, Damjan Marion wrote:
>> 
>>> 
>>> On May 1, 2012, at 7:43 AM, Tim Kientzle wrote:
>>>> 
>>>> The only odd point:  The ARM reference I have lists blx
>>>> only for ARMv6 and ARMv7 instruction sets … or am I
>>>> misreading that somehow?
>>> 
>>> BX and BLX are supported since ARMv5 in ARM mode and since ARMv4 in THUMB mode so this will break some very old stuff like StrongARM which is ARMv4(non T).
>> 
>> Of the Atmel stuff, only the AT91RM9200 is ARM v4.  The rest is ARMv5.  I don't know that we support the callback to the bootloader for the Atmel port, but a lot of work went in for the AT91SAM stuff that might have snuck that kind of change in when I wasn't looking.
>> 
>> Warner
> 
> The rm9200 is ARMv4T so according to the ARM ARM it should be okay with
> the BX and BLX instructions.


OK.  The fact we're not running in Thumb mode won't be a problem?

Warner