thr3ads.net - Xen devel - [PATCH 0/4] ARM/early-printk: Improve reusability and add Calxeda support [May 2013]

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Andre Przywara

2013-May-24 10:42 UTC

[PATCH 0/4] ARM/early-printk: Improve reusability and add Calxeda support

The current early-printk support for ARM is rather hard-coded, making
it hard to add machines or tweak settings.
This series slightly moves some code to gather UART settings in
xen/arch/arm/Rules.mk instead of the actual .c files. Also it allows
two different machines with different settings to share the same
driver, which the last patch exploits to add support the Calxeda
Midway hardware.

This haven''t been extensively tested, but I looked at the generated
assembly and did some quick checks on Versatile Express.

Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>

Andre Przywara (4):
  arm/early-printk: calculate baud rate divisor from user provided
    value
  arm/early-printk: allow skipping of UART init
  arm/early-printk: move UART base address to Rules.mk
  arm/early-printk: add Calxeda Midway UART support

 xen/arch/arm/Rules.mk                   | 13 +++++++++++++
 xen/arch/arm/arm32/debug-exynos4210.inc |  6 ++----
 xen/arch/arm/arm32/debug-pl011.inc      |  6 ++----
 xen/arch/arm/arm32/head.S               |  2 ++
 xen/arch/arm/arm64/debug-pl011.inc      |  6 ++----
 xen/arch/arm/arm64/head.S               |  2 ++
 6 files changed, 23 insertions(+), 12 deletions(-)

-- 
1.7.12.1

Andre Przywara

2013-May-24 10:42 UTC

head link

[PATCH 1/4] arm/early-printk: calculate baud rate divisor from user provided value

For early-printk the used baud rate was hardcoded in the code, using
precalculated divisor values.
Let the calculation of these values be done by the preprocessor and
use a human readable value in xen/arch/arm/Rules.mk to drive this.

Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
---
 xen/arch/arm/Rules.mk                   | 3 +++
 xen/arch/arm/arm32/debug-exynos4210.inc | 4 ++--
 xen/arch/arm/arm32/debug-pl011.inc      | 4 ++--
 xen/arch/arm/arm64/debug-pl011.inc      | 4 ++--
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
index b6a6890..b4d6907 100644
--- a/xen/arch/arm/Rules.mk
+++ b/xen/arch/arm/Rules.mk
@@ -45,9 +45,11 @@ ifeq ($(debug),y)
 # TODO handle UART base address from make command line
 ifeq ($(CONFIG_EARLY_PRINTK), vexpress)
 EARLY_PRINTK_INC := pl011
+EARLY_PRINTK_BAUD := 38400
 endif
 ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
 EARLY_PRINTK_INC := exynos4210
+EARLY_PRINTK_BAUD := 115200
 endif
 
 ifneq ($(EARLY_PRINTK_INC),)
@@ -56,4 +58,5 @@ endif
 
 CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
 CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
+CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
 endif
diff --git a/xen/arch/arm/arm32/debug-exynos4210.inc
b/xen/arch/arm/arm32/debug-exynos4210.inc
index 4241640..4922148 100644
--- a/xen/arch/arm/arm32/debug-exynos4210.inc
+++ b/xen/arch/arm/arm32/debug-exynos4210.inc
@@ -38,9 +38,9 @@
         orr   \rd, \rd, #(0x7<<8)
         str   \rd, [\rc, #0x558]
 
-        mov   \rc, #4
+        mov   \rc, #(100000000 / EARLY_PRINTK_BAUD % 16)
         str   \rc, [\rb, #UFRACVAL]     /* -> UFRACVAL (Baud divisor
fraction) */
-        mov   \rc, #53
+        mov   \rc, #(100000000 / EARLY_PRINTK_BAUD / 16 - 1)
         str   \rc, [\rb, #UBRDIV]       /* -> UBRDIV (Baud divisor integer)
*/
         mov   \rc, #3                   /* 8n1 */
         str   \rc, [\rb, #ULCON]        /* -> (Line control) */
diff --git a/xen/arch/arm/arm32/debug-pl011.inc
b/xen/arch/arm/arm32/debug-pl011.inc
index 6954aeb..2d970ea 100644
--- a/xen/arch/arm/arm32/debug-pl011.inc
+++ b/xen/arch/arm/arm32/debug-pl011.inc
@@ -23,9 +23,9 @@
  * rc: scratch register 1
  * rd: scratch register 2 (unused here) */
 .macro early_uart_init rb, rc, rd
-        mov   \rc, #0x0
+        mov   \rc, #(7372800 / EARLY_PRINTK_BAUD % 16)
         str   \rc, [\rb, #0x28]     /* -> UARTFBRD (Baud divisor fraction)
*/
-        mov   \rc, #0x4             /* 7.3728MHz / 0x4 == 16 * 115200 */
+        mov   \rc, #(7372800 / EARLY_PRINTK_BAUD / 16)
         str   \rc, [\rb, #0x24]     /* -> UARTIBRD (Baud divisor integer) */
         mov   \rc, #0x60            /* 8n1 */
         str   \rc, [\rb, #0x2C]     /* -> UARTLCR_H (Line control) */
diff --git a/xen/arch/arm/arm64/debug-pl011.inc
b/xen/arch/arm/arm64/debug-pl011.inc
index ee6e0e0..7220940 100644
--- a/xen/arch/arm/arm64/debug-pl011.inc
+++ b/xen/arch/arm/arm64/debug-pl011.inc
@@ -24,9 +24,9 @@
  * xb: register which containts the UART base address
  * c: scratch register number */
 .macro early_uart_init xb, c
-        mov   x\c, #0x0
+        mov   x\c, #(7372800 / EARLY_PRINTK_BAUD % 16)
         strh  w\c, [\xb, #0x28]      /* -> UARTFBRD (Baud divisor fraction)
*/
-        mov   x\c, #0x4              /* 7.3728MHz / 0x4 == 16 * 115200 */
+        mov   x\c, #(7372800 / EARLY_PRINTK_BAUD / 16)
         strh  w\c, [\xb, #0x24]      /* -> UARTIBRD (Baud divisor integer)
*/
         mov   x\c, #0x60             /* 8n1 */
         str   w\c, [\xb, #0x2C]      /* -> UARTLCR_H (Line control) */
-- 
1.7.12.1

Andre Przywara

2013-May-24 10:42 UTC

head link

[PATCH 2/4] arm/early-printk: allow skipping of UART init

While it seems obvious to initialize the UART before using it, chances
are that some firmware code or the bootloader already did this.
So it may actually be a good idea to skip the initialization, in fact
this fixes early printk on my TC2 Versatile Express.
So provide an option in xen/arch/arm/Rules.mk to only initialize the
UART when needed.

Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
---
 xen/arch/arm/Rules.mk     | 2 ++
 xen/arch/arm/arm32/head.S | 2 ++
 xen/arch/arm/arm64/head.S | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
index b4d6907..fdcf73e 100644
--- a/xen/arch/arm/Rules.mk
+++ b/xen/arch/arm/Rules.mk
@@ -49,6 +49,7 @@ EARLY_PRINTK_BAUD := 38400
 endif
 ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
 EARLY_PRINTK_INC := exynos4210
+EARLY_PRINTK_INIT_UART := y
 EARLY_PRINTK_BAUD := 115200
 endif
 
@@ -57,6 +58,7 @@ EARLY_PRINTK := y
 endif
 
 CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
+CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
 CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
 CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
 endif
diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index ec7f640..0588d54 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -369,7 +369,9 @@ fail:   PRINT("- Boot failed -\r\n")
  * r11: Early UART base address
  * Clobbers r0-r2 */
 init_uart:
+#ifdef EARLY_PRINTK_INIT_UART
         early_uart_init r11, r1, r2
+#endif
         adr   r0, 1f
         b     puts                  /* Jump to puts */
 1:      .asciz "- UART enabled -\r\n"
diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
index 8955946..21b7e4d 100644
--- a/xen/arch/arm/arm64/head.S
+++ b/xen/arch/arm/arm64/head.S
@@ -116,7 +116,9 @@ boot_cpu:
 #ifdef EARLY_PRINTK
         ldr   x23, =EARLY_UART_BASE_ADDRESS /* x23 := UART base address */
         cbnz  x22, 1f
+#ifdef EARLY_PRINTK_INIT_UART
         bl    init_uart                 /* CPU 0 sets up the UART too */
+#endif
 1:      PRINT("- CPU ")
         mov   x0, x22
         bl    putn
-- 
1.7.12.1

Andre Przywara

2013-May-24 10:42 UTC

head link

[PATCH 3/4] arm/early-printk: move UART base address to Rules.mk

The UART memory mapped base address is currently hardcoded in the
early-printk UART driver, which denies the driver to be used by
two machines with a different mapping.
Move this definition out to xen/arch/arm/Rules.mk, allowing easier
user access and later sharing of the driver.

Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
---
 xen/arch/arm/Rules.mk                   | 3 +++
 xen/arch/arm/arm32/debug-exynos4210.inc | 2 --
 xen/arch/arm/arm32/debug-pl011.inc      | 2 --
 xen/arch/arm/arm64/debug-pl011.inc      | 2 --
 4 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
index fdcf73e..37a8271 100644
--- a/xen/arch/arm/Rules.mk
+++ b/xen/arch/arm/Rules.mk
@@ -46,11 +46,13 @@ ifeq ($(debug),y)
 ifeq ($(CONFIG_EARLY_PRINTK), vexpress)
 EARLY_PRINTK_INC := pl011
 EARLY_PRINTK_BAUD := 38400
+EARLY_UART_BASE_ADDRESS := 0x1c090000
 endif
 ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
 EARLY_PRINTK_INC := exynos4210
 EARLY_PRINTK_INIT_UART := y
 EARLY_PRINTK_BAUD := 115200
+EARLY_UART_BASE_ADDRESS := 0x12c20000
 endif
 
 ifneq ($(EARLY_PRINTK_INC),)
@@ -61,4 +63,5 @@ CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
 CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
 CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
 CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
+CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_BASE_ADDRESS=$(EARLY_UART_BASE_ADDRESS)
 endif
diff --git a/xen/arch/arm/arm32/debug-exynos4210.inc
b/xen/arch/arm/arm32/debug-exynos4210.inc
index 4922148..d746c35 100644
--- a/xen/arch/arm/arm32/debug-exynos4210.inc
+++ b/xen/arch/arm/arm32/debug-exynos4210.inc
@@ -18,8 +18,6 @@
 
 #include <asm/exynos4210-uart.h>
 
-#define EARLY_UART_BASE_ADDRESS 0x12c20000
-
 /* Exynos 5 UART initialization
  * rb: register which contains the UART base address
  * rc: scratch register 1
diff --git a/xen/arch/arm/arm32/debug-pl011.inc
b/xen/arch/arm/arm32/debug-pl011.inc
index 2d970ea..8b085b8 100644
--- a/xen/arch/arm/arm32/debug-pl011.inc
+++ b/xen/arch/arm/arm32/debug-pl011.inc
@@ -16,8 +16,6 @@
  * GNU General Public License for more details.
  */
 
-#define EARLY_UART_BASE_ADDRESS 0x1c090000
-
 /* PL011 UART initialization
  * rb: register which contains the UART base address
  * rc: scratch register 1
diff --git a/xen/arch/arm/arm64/debug-pl011.inc
b/xen/arch/arm/arm64/debug-pl011.inc
index 7220940..b416235 100644
--- a/xen/arch/arm/arm64/debug-pl011.inc
+++ b/xen/arch/arm/arm64/debug-pl011.inc
@@ -18,8 +18,6 @@
 
 #include <asm/asm_defns.h>
 
-#define EARLY_UART_BASE_ADDRESS 0x1c090000
-
 /* PL011 UART initialization
  * xb: register which containts the UART base address
  * c: scratch register number */
-- 
1.7.12.1

Andre Przywara

2013-May-24 10:42 UTC

head link

[PATCH 4/4] arm/early-printk: add Calxeda Midway UART support

With the help of the last three patches add a stanza to
xen/arch/arm/Rules.mk to specify the UART configuration of the
Calxeda Midway machine.
The information has been taken from the Linux kernel''s .dts file.
This can be enabled by adding "CONFIG_EARLY_PRINTK=midway" to
Config.mk.

Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
---
 xen/arch/arm/Rules.mk | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
index 37a8271..cfc9e4d 100644
--- a/xen/arch/arm/Rules.mk
+++ b/xen/arch/arm/Rules.mk
@@ -54,6 +54,11 @@ EARLY_PRINTK_INIT_UART := y
 EARLY_PRINTK_BAUD := 115200
 EARLY_UART_BASE_ADDRESS := 0x12c20000
 endif
+ifeq ($(CONFIG_EARLY_PRINTK), midway)
+EARLY_PRINTK_INC := pl011
+EARLY_PRINTK_BAUD := 115200
+EARLY_UART_BASE_ADDRESS := 0xfff36000
+endif
 
 ifneq ($(EARLY_PRINTK_INC),)
 EARLY_PRINTK := y
-- 
1.7.12.1

Julien Grall

2013-May-24 12:15 UTC

head link

Re: [PATCH 1/4] arm/early-printk: calculate baud rate divisor from user provided value

On 05/24/2013 11:42 AM, Andre Przywara wrote:
> For early-printk the used baud rate was hardcoded in the code, using
> precalculated divisor values.
> Let the calculation of these values be done by the preprocessor and
> use a human readable value in xen/arch/arm/Rules.mk to drive this.
> 
> Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
> ---
>  xen/arch/arm/Rules.mk                   | 3 +++
>  xen/arch/arm/arm32/debug-exynos4210.inc | 4 ++--
>  xen/arch/arm/arm32/debug-pl011.inc      | 4 ++--
>  xen/arch/arm/arm64/debug-pl011.inc      | 4 ++--
>  4 files changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
> index b6a6890..b4d6907 100644
> --- a/xen/arch/arm/Rules.mk
> +++ b/xen/arch/arm/Rules.mk
> @@ -45,9 +45,11 @@ ifeq ($(debug),y)
>  # TODO handle UART base address from make command line
>  ifeq ($(CONFIG_EARLY_PRINTK), vexpress)
>  EARLY_PRINTK_INC := pl011
> +EARLY_PRINTK_BAUD := 38400
>  endif
>  ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
>  EARLY_PRINTK_INC := exynos4210
> +EARLY_PRINTK_BAUD := 115200
>  endif
>  
>  ifneq ($(EARLY_PRINTK_INC),)
> @@ -56,4 +58,5 @@ endif
>  
>  CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
>  CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
> +CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
>  endif
> diff --git a/xen/arch/arm/arm32/debug-exynos4210.inc
b/xen/arch/arm/arm32/debug-exynos4210.inc
> index 4241640..4922148 100644
> --- a/xen/arch/arm/arm32/debug-exynos4210.inc
> +++ b/xen/arch/arm/arm32/debug-exynos4210.inc
> @@ -38,9 +38,9 @@
>          orr   \rd, \rd, #(0x7<<8)
>          str   \rd, [\rc, #0x558]
>  
> -        mov   \rc, #4
> +        mov   \rc, #(100000000 / EARLY_PRINTK_BAUD % 16)
>          str   \rc, [\rb, #UFRACVAL]     /* -> UFRACVAL (Baud divisor
fraction) */
> -        mov   \rc, #53
> +        mov   \rc, #(100000000 / EARLY_PRINTK_BAUD / 16 - 1)
>          str   \rc, [\rb, #UBRDIV]       /* -> UBRDIV (Baud divisor
integer) */
>          mov   \rc, #3                   /* 8n1 */
>          str   \rc, [\rb, #ULCON]        /* -> (Line control) */
> diff --git a/xen/arch/arm/arm32/debug-pl011.inc
b/xen/arch/arm/arm32/debug-pl011.inc
> index 6954aeb..2d970ea 100644
> --- a/xen/arch/arm/arm32/debug-pl011.inc
> +++ b/xen/arch/arm/arm32/debug-pl011.inc
> @@ -23,9 +23,9 @@
>   * rc: scratch register 1
>   * rd: scratch register 2 (unused here) */
>  .macro early_uart_init rb, rc, rd
> -        mov   \rc, #0x0
> +        mov   \rc, #(7372800 / EARLY_PRINTK_BAUD % 16)
>          str   \rc, [\rb, #0x28]     /* -> UARTFBRD (Baud divisor
fraction) */
> -        mov   \rc, #0x4             /* 7.3728MHz / 0x4 == 16 * 115200 */
> +        mov   \rc, #(7372800 / EARLY_PRINTK_BAUD / 16)
>          str   \rc, [\rb, #0x24]     /* -> UARTIBRD (Baud divisor
integer) */
>          mov   \rc, #0x60            /* 8n1 */
>          str   \rc, [\rb, #0x2C]     /* -> UARTLCR_H (Line control) */
> diff --git a/xen/arch/arm/arm64/debug-pl011.inc
b/xen/arch/arm/arm64/debug-pl011.inc
> index ee6e0e0..7220940 100644
> --- a/xen/arch/arm/arm64/debug-pl011.inc
> +++ b/xen/arch/arm/arm64/debug-pl011.inc
> @@ -24,9 +24,9 @@
>   * xb: register which containts the UART base address
>   * c: scratch register number */
>  .macro early_uart_init xb, c
> -        mov   x\c, #0x0
> +        mov   x\c, #(7372800 / EARLY_PRINTK_BAUD % 16)
>          strh  w\c, [\xb, #0x28]      /* -> UARTFBRD (Baud divisor
fraction) */
> -        mov   x\c, #0x4              /* 7.3728MHz / 0x4 == 16 * 115200 */
> +        mov   x\c, #(7372800 / EARLY_PRINTK_BAUD / 16)
>          strh  w\c, [\xb, #0x24]      /* -> UARTIBRD (Baud divisor
integer) */
>          mov   x\c, #0x60             /* 8n1 */
>          str   w\c, [\xb, #0x2C]      /* -> UARTLCR_H (Line control) */

Julien Grall

2013-May-24 12:30 UTC

head link

Re: [PATCH 2/4] arm/early-printk: allow skipping of UART init

On 05/24/2013 11:42 AM, Andre Przywara wrote:
> While it seems obvious to initialize the UART before using it, chances
> are that some firmware code or the bootloader already did this.
> So it may actually be a good idea to skip the initialization, in fact
> this fixes early printk on my TC2 Versatile Express.
> So provide an option in xen/arch/arm/Rules.mk to only initialize the
> UART when needed.

I''m using the fast model: Fast Models [8.0.60 (Mar  7 2013)] and the
UART initialization is needed.

Could you do one of the following option:
    1) add fastmodel early printk (with EARLY_PRINTK_INIT_UART=y)
    2) document the behavior in docs/misc/arm/early-printk.txt
> Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
> ---
>  xen/arch/arm/Rules.mk     | 2 ++
>  xen/arch/arm/arm32/head.S | 2 ++
>  xen/arch/arm/arm64/head.S | 2 ++
>  3 files changed, 6 insertions(+)
> 
> diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
> index b4d6907..fdcf73e 100644
> --- a/xen/arch/arm/Rules.mk
> +++ b/xen/arch/arm/Rules.mk
> @@ -49,6 +49,7 @@ EARLY_PRINTK_BAUD := 38400
>  endif
>  ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
>  EARLY_PRINTK_INC := exynos4210
> +EARLY_PRINTK_INIT_UART := y
>  EARLY_PRINTK_BAUD := 115200
>  endif
>  
> @@ -57,6 +58,7 @@ EARLY_PRINTK := y
>  endif
>  
>  CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
> +CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
>  CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
>  CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
>  endif
> diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
> index ec7f640..0588d54 100644
> --- a/xen/arch/arm/arm32/head.S
> +++ b/xen/arch/arm/arm32/head.S
> @@ -369,7 +369,9 @@ fail:   PRINT("- Boot failed -\r\n")
>   * r11: Early UART base address
>   * Clobbers r0-r2 */
>  init_uart:
> +#ifdef EARLY_PRINTK_INIT_UART
>          early_uart_init r11, r1, r2
> +#endif
>          adr   r0, 1f
>          b     puts                  /* Jump to puts */
>  1:      .asciz "- UART enabled -\r\n"
> diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
> index 8955946..21b7e4d 100644
> --- a/xen/arch/arm/arm64/head.S
> +++ b/xen/arch/arm/arm64/head.S
> @@ -116,7 +116,9 @@ boot_cpu:
>  #ifdef EARLY_PRINTK
>          ldr   x23, =EARLY_UART_BASE_ADDRESS /* x23 := UART base address */
>          cbnz  x22, 1f
> +#ifdef EARLY_PRINTK_INIT_UART
>          bl    init_uart                 /* CPU 0 sets up the UART too */
> +#endif
>  1:      PRINT("- CPU ")
>          mov   x0, x22
>          bl    putn

-- 
Julien

Julien Grall

2013-May-24 12:36 UTC

head link

Re: [PATCH 3/4] arm/early-printk: move UART base address to Rules.mk

On 05/24/2013 11:42 AM, Andre Przywara wrote:
> The UART memory mapped base address is currently hardcoded in the
> early-printk UART driver, which denies the driver to be used by
> two machines with a different mapping.
> Move this definition out to xen/arch/arm/Rules.mk, allowing easier
> user access and later sharing of the driver.
> 
> Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
Reviewed-by: Julien Grall <julien.grall@linaro.org>
> ---
>  xen/arch/arm/Rules.mk                   | 3 +++
>  xen/arch/arm/arm32/debug-exynos4210.inc | 2 --
>  xen/arch/arm/arm32/debug-pl011.inc      | 2 --
>  xen/arch/arm/arm64/debug-pl011.inc      | 2 --
>  4 files changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
> index fdcf73e..37a8271 100644
> --- a/xen/arch/arm/Rules.mk
> +++ b/xen/arch/arm/Rules.mk
> @@ -46,11 +46,13 @@ ifeq ($(debug),y)
>  ifeq ($(CONFIG_EARLY_PRINTK), vexpress)
>  EARLY_PRINTK_INC := pl011
>  EARLY_PRINTK_BAUD := 38400
> +EARLY_UART_BASE_ADDRESS := 0x1c090000
>  endif
>  ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
>  EARLY_PRINTK_INC := exynos4210
>  EARLY_PRINTK_INIT_UART := y
>  EARLY_PRINTK_BAUD := 115200
> +EARLY_UART_BASE_ADDRESS := 0x12c20000
>  endif
>  
>  ifneq ($(EARLY_PRINTK_INC),)
> @@ -61,4 +63,5 @@ CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
>  CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
>  CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
>  CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
> +CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_UART_BASE_ADDRESS=$(EARLY_UART_BASE_ADDRESS)
>  endif
> diff --git a/xen/arch/arm/arm32/debug-exynos4210.inc
b/xen/arch/arm/arm32/debug-exynos4210.inc
> index 4922148..d746c35 100644
> --- a/xen/arch/arm/arm32/debug-exynos4210.inc
> +++ b/xen/arch/arm/arm32/debug-exynos4210.inc
> @@ -18,8 +18,6 @@
>  
>  #include <asm/exynos4210-uart.h>
>  
> -#define EARLY_UART_BASE_ADDRESS 0x12c20000
> -
>  /* Exynos 5 UART initialization
>   * rb: register which contains the UART base address
>   * rc: scratch register 1
> diff --git a/xen/arch/arm/arm32/debug-pl011.inc
b/xen/arch/arm/arm32/debug-pl011.inc
> index 2d970ea..8b085b8 100644
> --- a/xen/arch/arm/arm32/debug-pl011.inc
> +++ b/xen/arch/arm/arm32/debug-pl011.inc
> @@ -16,8 +16,6 @@
>   * GNU General Public License for more details.
>   */
>  
> -#define EARLY_UART_BASE_ADDRESS 0x1c090000
> -
>  /* PL011 UART initialization
>   * rb: register which contains the UART base address
>   * rc: scratch register 1
> diff --git a/xen/arch/arm/arm64/debug-pl011.inc
b/xen/arch/arm/arm64/debug-pl011.inc
> index 7220940..b416235 100644
> --- a/xen/arch/arm/arm64/debug-pl011.inc
> +++ b/xen/arch/arm/arm64/debug-pl011.inc
> @@ -18,8 +18,6 @@
>  
>  #include <asm/asm_defns.h>
>  
> -#define EARLY_UART_BASE_ADDRESS 0x1c090000
> -
>  /* PL011 UART initialization
>   * xb: register which containts the UART base address
>   * c: scratch register number */

Julien Grall

2013-May-24 12:38 UTC

head link

Re: [PATCH 4/4] arm/early-printk: add Calxeda Midway UART support

On 05/24/2013 11:42 AM, Andre Przywara wrote:
> With the help of the last three patches add a stanza to
> xen/arch/arm/Rules.mk to specify the UART configuration of the
> Calxeda Midway machine.
> The information has been taken from the Linux kernel''s .dts file.
> This can be enabled by adding "CONFIG_EARLY_PRINTK=midway" to
> Config.mk.
Could add a line in docs/misc/arm/early-printk.txt to document this new
early printk?

Thanks,

Julien
> Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
> ---
>  xen/arch/arm/Rules.mk | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
> index 37a8271..cfc9e4d 100644
> --- a/xen/arch/arm/Rules.mk
> +++ b/xen/arch/arm/Rules.mk
> @@ -54,6 +54,11 @@ EARLY_PRINTK_INIT_UART := y
>  EARLY_PRINTK_BAUD := 115200
>  EARLY_UART_BASE_ADDRESS := 0x12c20000
>  endif
> +ifeq ($(CONFIG_EARLY_PRINTK), midway)
> +EARLY_PRINTK_INC := pl011
> +EARLY_PRINTK_BAUD := 115200
> +EARLY_UART_BASE_ADDRESS := 0xfff36000
> +endif
>  
>  ifneq ($(EARLY_PRINTK_INC),)
>  EARLY_PRINTK := y

Julien Grall

2013-May-24 12:40 UTC

head link

Re: [PATCH 0/4] ARM/early-printk: Improve reusability and add Calxeda support

On 05/24/2013 11:42 AM, Andre Przywara wrote:
> The current early-printk support for ARM is rather hard-coded, making
> it hard to add machines or tweak settings.
> This series slightly moves some code to gather UART settings in
> xen/arch/arm/Rules.mk instead of the actual .c files. Also it allows
> two different machines with different settings to share the same
> driver, which the last patch exploits to add support the Calxeda
> Midway hardware.
> 
> This haven''t been extensively tested, but I looked at the
generated
> assembly and did some quick checks on Versatile Express.

Thanks for this patch series, the UART code is now more generic :).

I tried all these patches on the fast model and the arndale board. I
didn''t see any specific issue.

Cheers,

Julien
> 
> Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
> 
> Andre Przywara (4):
>   arm/early-printk: calculate baud rate divisor from user provided
>     value
>   arm/early-printk: allow skipping of UART init
>   arm/early-printk: move UART base address to Rules.mk
>   arm/early-printk: add Calxeda Midway UART support
> 
>  xen/arch/arm/Rules.mk                   | 13 +++++++++++++
>  xen/arch/arm/arm32/debug-exynos4210.inc |  6 ++----
>  xen/arch/arm/arm32/debug-pl011.inc      |  6 ++----
>  xen/arch/arm/arm32/head.S               |  2 ++
>  xen/arch/arm/arm64/debug-pl011.inc      |  6 ++----
>  xen/arch/arm/arm64/head.S               |  2 ++
>  6 files changed, 23 insertions(+), 12 deletions(-)
>

Julien Grall

2013-May-24 12:51 UTC

head link

Re: [PATCH 3/4] arm/early-printk: move UART base address to Rules.mk

On 05/24/2013 01:36 PM, Julien Grall wrote:
> On 05/24/2013 11:42 AM, Andre Przywara wrote:
> 
>> The UART memory mapped base address is currently hardcoded in the
>> early-printk UART driver, which denies the driver to be used by
>> two machines with a different mapping.
>> Move this definition out to xen/arch/arm/Rules.mk, allowing easier
>> user access and later sharing of the driver.
>>
>> Signed-off-by: Andre Przywara <andre.przywara@calxeda.com>
> 
> Reviewed-by: Julien Grall <julien.grall@linaro.org>

By the way, could you remove the "# TODO handle UART..." in
arch/arm/Rules.mk as you have implemented it?

Thanks,

Julien
>> ---
>>  xen/arch/arm/Rules.mk                   | 3 +++
>>  xen/arch/arm/arm32/debug-exynos4210.inc | 2 --
>>  xen/arch/arm/arm32/debug-pl011.inc      | 2 --
>>  xen/arch/arm/arm64/debug-pl011.inc      | 2 --
>>  4 files changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
>> index fdcf73e..37a8271 100644
>> --- a/xen/arch/arm/Rules.mk
>> +++ b/xen/arch/arm/Rules.mk
>> @@ -46,11 +46,13 @@ ifeq ($(debug),y)
>>  ifeq ($(CONFIG_EARLY_PRINTK), vexpress)
>>  EARLY_PRINTK_INC := pl011
>>  EARLY_PRINTK_BAUD := 38400
>> +EARLY_UART_BASE_ADDRESS := 0x1c090000
>>  endif
>>  ifeq ($(CONFIG_EARLY_PRINTK), exynos5250)
>>  EARLY_PRINTK_INC := exynos4210
>>  EARLY_PRINTK_INIT_UART := y
>>  EARLY_PRINTK_BAUD := 115200
>> +EARLY_UART_BASE_ADDRESS := 0x12c20000
>>  endif
>>  
>>  ifneq ($(EARLY_PRINTK_INC),)
>> @@ -61,4 +63,5 @@ CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK
>>  CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART
>>  CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\"
>>  CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD)
>> +CFLAGS-$(EARLY_PRINTK) +=
-DEARLY_UART_BASE_ADDRESS=$(EARLY_UART_BASE_ADDRESS)
>>  endif
>> diff --git a/xen/arch/arm/arm32/debug-exynos4210.inc
b/xen/arch/arm/arm32/debug-exynos4210.inc
>> index 4922148..d746c35 100644
>> --- a/xen/arch/arm/arm32/debug-exynos4210.inc
>> +++ b/xen/arch/arm/arm32/debug-exynos4210.inc
>> @@ -18,8 +18,6 @@
>>  
>>  #include <asm/exynos4210-uart.h>
>>  
>> -#define EARLY_UART_BASE_ADDRESS 0x12c20000
>> -
>>  /* Exynos 5 UART initialization
>>   * rb: register which contains the UART base address
>>   * rc: scratch register 1
>> diff --git a/xen/arch/arm/arm32/debug-pl011.inc
b/xen/arch/arm/arm32/debug-pl011.inc
>> index 2d970ea..8b085b8 100644
>> --- a/xen/arch/arm/arm32/debug-pl011.inc
>> +++ b/xen/arch/arm/arm32/debug-pl011.inc
>> @@ -16,8 +16,6 @@
>>   * GNU General Public License for more details.
>>   */
>>  
>> -#define EARLY_UART_BASE_ADDRESS 0x1c090000
>> -
>>  /* PL011 UART initialization
>>   * rb: register which contains the UART base address
>>   * rc: scratch register 1
>> diff --git a/xen/arch/arm/arm64/debug-pl011.inc
b/xen/arch/arm/arm64/debug-pl011.inc
>> index 7220940..b416235 100644
>> --- a/xen/arch/arm/arm64/debug-pl011.inc
>> +++ b/xen/arch/arm/arm64/debug-pl011.inc
>> @@ -18,8 +18,6 @@
>>  
>>  #include <asm/asm_defns.h>
>>  
>> -#define EARLY_UART_BASE_ADDRESS 0x1c090000
>> -
>>  /* PL011 UART initialization
>>   * xb: register which containts the UART base address
>>   * c: scratch register number */
> 
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

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