[PATCH 0/2] readline_simple: return -1 if getc fails

[Gaël PORTAY]

Hi,

On Wed, Aug 09, 2017 at 08:05:57AM +0200, Oleksij Rempel wrote:
> Am 09.08.2017 um 06:13 schrieb Gaël PORTAY:
> > Dear maintainers,
> > 
> > I came accross this issue when I was trying to add support for a new MIPS
> > board.
> 
> Just out of curiosity, what MIPS board are you working on? If it is not
> a secret :)
> 

I am working on VoCore2[1]; it is a board based on a mediatek mt7628 CPU.

I am doing this to learn myself how works barebox 

Offtopic: For now it is booting on a really really old version of u-boot. I am
able de boot barebox from u-boot. I had to hack the mips_disable_interrupts to
remove the reset of flag ERL in CP0; but I don't know why yet. This flag is
supposed to be set when CPU reboots; but because I am running barebox from a the
command go of u-boot, this flag is unset.

Are you able to re-run barebox from barebox on your MIPS board?

	.macro	mips_disable_interrupts
	.set	push
	.set	noreorder
	mfc0	k0, CP0_STATUS
-	li	k1, ~(ST0_ERL | ST0_IE)
+	li	k1, ~ST0_IE
	and	k0, k1
	mtc0	k0, CP0_STATUS
	.set	pop
	.endm

For now, I have splitted mips_disable_interrupts into two macros. The second
macro mips_reset_error_level checks if the ERL flag is armed before resetting it
to 0.

	.macro	mips_reset_error_level
	.set	push
	.set	noreorder
	mfc0	k0, CP0_STATUS
	li	k1, ST0_ERL
	and	k1, k0
	bne	k1, zero, 1f
	li	k1, ~(ST0_ERL)
	and	k0, k1
	mtc0	k0, CP0_STATUS
1:	.set	pop
	.endm

But I don't know if this is the right thing to do.
 
[1]: https://www.indiegogo.com/projects/vocore2-4-coin-sized-linux-computer-with-wifi#/