* Xen-arm patch to early init_uart in head.S
@ 2013-01-10 19:18 lra
2013-01-11 10:03 ` Ian Campbell
0 siblings, 1 reply; 6+ messages in thread
From: lra @ 2013-01-10 19:18 UTC (permalink / raw)
To: xen-devel@lists.xensource.com
Hi,
reading the PL011 UART documentation on
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0183f/DDI0183.pdf
I noticed the early initialisation of the UART on the Versatile Express
is incorrect. (Currently it probably works only because the default
values are sane.)
Cheers,
/Lars
>From 7184ce113d907ce8cf366dddbe8145e59987a656 Mon Sep 17 00:00:00 2001
From: Lars Rasmusson <Lars.Rasmusson@sics.se>
Date: Thu, 10 Jan 2013 17:10:44 +0100
Subject: [PATCH] Fixed register values and comment in early init_uart to
match documentation of PL011 UART
Signed-off-by: Lars Rasmusson <Lars.Rasmusson@sics.se>
---
xen/arch/arm/head.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/head.S b/xen/arch/arm/head.S
index cdbe011..a884592 100644
--- a/xen/arch/arm/head.S
+++ b/xen/arch/arm/head.S
@@ -291,11 +291,11 @@ fail: PRINT("- Boot failed -\r\n")
* Clobbers r0-r2 */
init_uart:
mov r1, #0x0
- str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor fraction) */
+ str r1, [r11, #0x28] /* -> UARTFBRD (Baud divisor fraction) */
mov r1, #0x4 /* 7.3728MHz / 0x4 == 16 * 115200 */
str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor integer) */
mov r1, #0x60 /* 8n1 */
- str r1, [r11, #0x24] /* -> UARTLCR_H (Line control) */
+ str r1, [r11, #0x2C] /* -> UARTLCR_H (Line control) */
ldr r1, =0x00000301 /* RXE | TXE | UARTEN */
str r1, [r11, #0x30] /* -> UARTCR (Control Register) */
adr r0, 1f
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: Xen-arm patch to early init_uart in head.S
2013-01-10 19:18 Xen-arm patch to early init_uart in head.S lra
@ 2013-01-11 10:03 ` Ian Campbell
2013-01-17 13:19 ` Ian Campbell
0 siblings, 1 reply; 6+ messages in thread
From: Ian Campbell @ 2013-01-11 10:03 UTC (permalink / raw)
To: lra@sics.se; +Cc: xen-devel@lists.xensource.com
On Thu, 2013-01-10 at 19:18 +0000, lra@sics.se wrote:
> Hi,
>
> reading the PL011 UART documentation on
> http://infocenter.arm.com/help/topic/com.arm.doc.ddi0183f/DDI0183.pdf
>
> I noticed the early initialisation of the UART on the Versatile Express
> is incorrect. (Currently it probably works only because the default
> values are sane.)
Good catch! Thanks.
> From 7184ce113d907ce8cf366dddbe8145e59987a656 Mon Sep 17 00:00:00 2001
> From: Lars Rasmusson <Lars.Rasmusson@sics.se>
> Date: Thu, 10 Jan 2013 17:10:44 +0100
> Subject: [PATCH] Fixed register values and comment in early init_uart to
> match documentation of PL011 UART
>
> Signed-off-by: Lars Rasmusson <Lars.Rasmusson@sics.se>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
> ---
> xen/arch/arm/head.S | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/xen/arch/arm/head.S b/xen/arch/arm/head.S
> index cdbe011..a884592 100644
> --- a/xen/arch/arm/head.S
> +++ b/xen/arch/arm/head.S
> @@ -291,11 +291,11 @@ fail: PRINT("- Boot failed -\r\n")
> * Clobbers r0-r2 */
> init_uart:
> mov r1, #0x0
> - str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor fraction) */
> + str r1, [r11, #0x28] /* -> UARTFBRD (Baud divisor fraction) */
> mov r1, #0x4 /* 7.3728MHz / 0x4 == 16 * 115200 */
> str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor integer) */
> mov r1, #0x60 /* 8n1 */
> - str r1, [r11, #0x24] /* -> UARTLCR_H (Line control) */
> + str r1, [r11, #0x2C] /* -> UARTLCR_H (Line control) */
> ldr r1, =0x00000301 /* RXE | TXE | UARTEN */
> str r1, [r11, #0x30] /* -> UARTCR (Control Register) */
> adr r0, 1f
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: Xen-arm patch to early init_uart in head.S
2013-01-11 10:03 ` Ian Campbell
@ 2013-01-17 13:19 ` Ian Campbell
2013-01-17 14:08 ` [PATCH] Set register values and comment in early init_uart to match documentation of PL011 UART lra
0 siblings, 1 reply; 6+ messages in thread
From: Ian Campbell @ 2013-01-17 13:19 UTC (permalink / raw)
To: lra@sics.se; +Cc: xen-devel@lists.xensource.com
On Fri, 2013-01-11 at 10:03 +0000, Ian Campbell wrote:
> On Thu, 2013-01-10 at 19:18 +0000, lra@sics.se wrote:
> > Hi,
> >
> > reading the PL011 UART documentation on
> > http://infocenter.arm.com/help/topic/com.arm.doc.ddi0183f/DDI0183.pdf
> >
> > I noticed the early initialisation of the UART on the Versatile Express
> > is incorrect. (Currently it probably works only because the default
> > values are sane.)
>
> Good catch! Thanks.
>
> > From 7184ce113d907ce8cf366dddbe8145e59987a656 Mon Sep 17 00:00:00 2001
> > From: Lars Rasmusson <Lars.Rasmusson@sics.se>
> > Date: Thu, 10 Jan 2013 17:10:44 +0100
> > Subject: [PATCH] Fixed register values and comment in early init_uart to
> > match documentation of PL011 UART
> >
> > Signed-off-by: Lars Rasmusson <Lars.Rasmusson@sics.se>
>
> Acked-by: Ian Campbell <ian.campbell@citrix.com>
I'm afraid this patch doesn't apply, I think it is based on a tree prior
to moving head.S -> arm32/head.S and fixing up the whitespace.
Could you rebase please?
Thanks,
Ian.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] Set register values and comment in early init_uart to match documentation of PL011 UART
2013-01-17 13:19 ` Ian Campbell
@ 2013-01-17 14:08 ` lra
2013-01-17 16:49 ` Ian Campbell
0 siblings, 1 reply; 6+ messages in thread
From: lra @ 2013-01-17 14:08 UTC (permalink / raw)
To: xen-devel; +Cc: Lars Rasmusson
From: Lars Rasmusson <Lars.Rasmusson@sics.se>
Reading the PL011 UART documentation on
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0183f/DDI0183.pdf
in sec 3.2 shows the early initialisation of the UART on the Versatile Express
is incorrect. This fixes it.
Signed-off-by: Lars Rasmusson <Lars.Rasmusson@sics.se>
---
xen/arch/arm/arm32/head.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index 4782f11..20e9da6 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -352,11 +352,11 @@ fail: PRINT("- Boot failed -\r\n")
* Clobbers r0-r2 */
init_uart:
mov r1, #0x0
- str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor fraction) */
+ str r1, [r11, #0x28] /* -> UARTFBRD (Baud divisor fraction) */
mov r1, #0x4 /* 7.3728MHz / 0x4 == 16 * 115200 */
str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor integer) */
mov r1, #0x60 /* 8n1 */
- str r1, [r11, #0x24] /* -> UARTLCR_H (Line control) */
+ str r1, [r11, #0x2C] /* -> UARTLCR_H (Line control) */
ldr r1, =0x00000301 /* RXE | TXE | UARTEN */
str r1, [r11, #0x30] /* -> UARTCR (Control Register) */
adr r0, 1f
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] Set register values and comment in early init_uart to match documentation of PL011 UART
@ 2013-01-10 20:02 lra
0 siblings, 0 replies; 6+ messages in thread
From: lra @ 2013-01-10 20:02 UTC (permalink / raw)
To: xen-devel; +Cc: Lars Rasmusson
From: Lars Rasmusson <Lars.Rasmusson@sics.se>
Reading the PL011 UART documentation on
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0183f/DDI0183.pdf
in sec 3.2 shows the early initialisation of the UART on the Versatile Express
is incorrect. (Currently it probably works only because the default
values are sane.)
Signed-off-by: Lars Rasmusson <Lars.Rasmusson@sics.se>
---
xen/arch/arm/head.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/head.S b/xen/arch/arm/head.S
index cdbe011..a884592 100644
--- a/xen/arch/arm/head.S
+++ b/xen/arch/arm/head.S
@@ -291,11 +291,11 @@ fail: PRINT("- Boot failed -\r\n")
* Clobbers r0-r2 */
init_uart:
mov r1, #0x0
- str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor fraction) */
+ str r1, [r11, #0x28] /* -> UARTFBRD (Baud divisor fraction) */
mov r1, #0x4 /* 7.3728MHz / 0x4 == 16 * 115200 */
str r1, [r11, #0x24] /* -> UARTIBRD (Baud divisor integer) */
mov r1, #0x60 /* 8n1 */
- str r1, [r11, #0x24] /* -> UARTLCR_H (Line control) */
+ str r1, [r11, #0x2C] /* -> UARTLCR_H (Line control) */
ldr r1, =0x00000301 /* RXE | TXE | UARTEN */
str r1, [r11, #0x30] /* -> UARTCR (Control Register) */
adr r0, 1f
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
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2013-01-10 19:18 Xen-arm patch to early init_uart in head.S lra
2013-01-11 10:03 ` Ian Campbell
2013-01-17 13:19 ` Ian Campbell
2013-01-17 14:08 ` [PATCH] Set register values and comment in early init_uart to match documentation of PL011 UART lra
2013-01-17 16:49 ` Ian Campbell
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