RE: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-09-18 Thread Pandita, Vikram 


-Original Message-
From: Russell King - ARM Linux [mailto:li...@arm.linux.org.uk]
Sent: Thursday, September 17, 2009 2:48 PM
To: Pandita, Vikram
Cc: Kevin Hilman; linux-omap@vger.kernel.org; 
linux-arm-ker...@lists.arm.linux.org.uk
Subject: Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

On Fri, Sep 18, 2009 at 12:30:25AM +0530, Pandita, Vikram wrote:
 There are review comments by Kevin [2] still getting fixed,
 but a 'Russell-look' will surely help to the in-lined patch [3] .

Still not good.

I have considered all your comments for this patch and 
am working on a new approach.

I should be able to post V3 patch set in a day or so, 
which does not touch any of the common files.



 +mov r9, r0
 +
 +bl  get_uart_base   @ get uart phy address
 +adr r2, __dummy
 +str r0, [r2]@save uart phy adder in memory
 +ldm r2, {r13}^  @save phyadder in usermode reg
 +
 +bl  get_uart_virt_base  @ get uart virtual address
 +adr r2, __dummy
 +str r0, [r2]@save uart phy adder in memory
 +ldm r2, {r14}^  @save phyadder in usermode reg
 +
 +mov r0, r9
 +
  bl  cache_clean_flush
  add pc, r5, r0  @ call relocation code

 @@ -303,6 +317,9 @@  LC0:.word   LC0 @ r1
  LC1:.word   reloc_end - reloc_start
  .size   LC0, . - LC0

 +.type   __dummy, #object
 +__dummy:.word   __dummy

This appears to be in the text segment, and is written to.  That's not
going to work if the text segment is stored in flash (and in fact might
be dangerous in some cases.)

 +
  #ifdef CONFIG_ARCH_RPC
  .globl  params
  params: ldr r0, =params_phys
 diff --git a/arch/arm/boot/compressed/misc.c 
 b/arch/arm/boot/compressed/misc.c
 index 17153b5..0758656 100644
 --- a/arch/arm/boot/compressed/misc.c
 +++ b/arch/arm/boot/compressed/misc.c
 @@ -22,6 +22,15 @@  unsigned int __machine_arch_type;
  #include linux/types.h/* for size_t */
  #include linux/stddef.h   /* for NULL */
  #include asm/string.h
 +#include asm/mach-types.h
 +/* TODO:
 + * Include of this header is not working.
 + * Gives Error: undefined reference to `omap_rev'
 + * This header is needed for constant:
 + * ZOOM2_EXT_QUART_VIRT = 0xFB00
 + * ZOOM2_EXT_QUART_PHYS = 0x1000
 + */
 +/* #include mach/io.h */

  #ifdef STANDALONE_DEBUG
  #define putstr printf
 @@ -316,6 +325,103 @@  static void error(char *x)

  #ifndef STANDALONE_DEBUG

 +u32  *omap_uart_debug_ll_phy_addr;
 +
 +static void find_debug_ll_uart_port(unsigned int arch_type)
 +{
 +omap_uart_debug_ll_phy_addr = 0;
 +
 +/* Add logic here for new platforms, using __macine_arch_type */
 +
 +/* TODO: REVISIT -- Check Completeness
 + * DEFINE PHY ADDRESS for EACH BOARD HERE: omap1/2/3/4 */
 +#if defined(CONFIG_ARCH_OMAP1)
 +switch (arch_type) {
 +case MACH_TYPE_OMAP_PALMTT:
 +case MACH_TYPE_SX1:
 +/* UART2 */
 +omap_uart_debug_ll_phy_addr = (u32 *)0xfffb0800;
 +break;
 +default:
 +/* UART1 */
 +omap_uart_debug_ll_phy_addr = (u32 *)0xfffb;
 +break;
 +}
 +#endif
 +
 +#if defined(CONFIG_ARCH_OMAP2)
 +switch (arch_type) {
 +case MACH_TYPE_NOKIA_N800:
 +case MACH_TYPE_NOKIA_N810:
 +case MACH_TYPE_NOKIA_N810_WIMAX:
 +/* UART3 */
 +omap_uart_debug_ll_phy_addr = (u32 *)0x4806e000;
 +break;
 +default:
 +/* UART1 */
 +omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
 +break;
 +}
 +#endif
 +
 +#if defined(CONFIG_ARCH_OMAP3)
 +switch (arch_type) {
 +case MACH_TYPE_OMAP_LDP:
 +case MACH_TYPE_OVERO:
 +case MACH_TYPE_OMAP3_PANDORA:
 +case MACH_TYPE_NOKIA_RX51:
 +case MACH_TYPE_OMAP3_BEAGLE:
 +/* UART3 */
 +omap_uart_debug_ll_phy_addr = (u32 *)0x4902;
 +break;
 +case MACH_TYPE_OMAP_ZOOM2:
 +/* EXTERNEL UART */
 +omap_uart_debug_ll_phy_addr = (u32 *)0x1000;
 +break;
 +default:
 +/* UART1 */
 +omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
 +break;
 +}
 +#endif
 +
 +#ifdef CONFIG_ARCH_OMAP4
 +switch (arch_type) {
 +/* OMAP3: UART1 */
 +case MACH_TYPE_OMAP_4430SDP:
 +default:
 +omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
 +putstr(This is an OMAP4 ...\n);
 +break;
 +}
 +#endif
 +}
 +
 +ulg
 +get_uart_base(void)
 +{
 +return (ulg)omap_uart_debug_ll_phy_addr;
 +}
 +
 +ulg
 +get_uart_virt_base(void)
 +{
 +ulg val = 0;
 +
 +#ifdef CONFIG_ARCH_OMAP1
 +/* omap1 */
 +val = 0xfef0;
 +#else
 +/* omap2/3/4... */
 +if (MACH_TYPE_OMAP_ZOOM2 == __machine_arch_type)
 +val

RE: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-09-17 Thread Pandita, Vikram 
Russell

-Original Message-
From: Russell King - ARM Linux [mailto:li...@arm.linux.org.uk]
Sent: Wednesday, September 16, 2009 2:11 PM
To: Kevin Hilman
Cc: Pandita, Vikram; linux-omap@vger.kernel.org; 
linux-arm-ker...@lists.arm.linux.org.uk
Subject: Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

On Thu, Aug 27, 2009 at 04:29:35PM +0300, Kevin Hilman wrote:
  The idea is to write to phys_io and io_pg_offset from kernel/head.S
  very early based on the uart address found in compressed/misc.c
 
  To make map_io writable, I will have to change the MACHINE_START to
  remove the const.  It so happens that Russell has defined
  MACHINE_START to be a const.
 
  Not sure is removing const from MACHINE_START is acceptable?

 we'll find out after you post for RFC.

The answer is no, it is not acceptable - it'll break XIP kernels
because this is placed into the read-only part of the kernel image
no matter what.

The good news is that Version 2 of DEBUG_LL cleanup patch [1], 
does not change the const attribute of MACHINE_START.

There are review comments by Kevin [2] still getting fixed, 
but a 'Russell-look' will surely help to the in-lined patch [3] .


Regards,
Vikram 

[1] git://dev.omapzoom.org/pub/scm/vikram/omap3.git runtime-debug-ll

[2] http://patchwork.kernel.org/patch/46909/

[3] Patch inlined below --- 

diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 4515728..7fcc21a 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -277,6 +277,20 @@  not_relocated:mov r0, #0
blo 1b
add sp, r1, #128@ relocate the stack
 
+   mov r9, r0
+
+   bl  get_uart_base   @ get uart phy address
+   adr r2, __dummy
+   str r0, [r2]@save uart phy adder in memory
+   ldm r2, {r13}^  @save phyadder in usermode reg
+
+   bl  get_uart_virt_base  @ get uart virtual address
+   adr r2, __dummy
+   str r0, [r2]@save uart phy adder in memory
+   ldm r2, {r14}^  @save phyadder in usermode reg
+
+   mov r0, r9
+
bl  cache_clean_flush
add pc, r5, r0  @ call relocation code
 
@@ -303,6 +317,9 @@  LC0:   .word   LC0 @ r1
 LC1:   .word   reloc_end - reloc_start
.size   LC0, . - LC0
 
+   .type   __dummy, #object
+__dummy:   .word   __dummy
+
 #ifdef CONFIG_ARCH_RPC
.globl  params
 params:ldr r0, =params_phys
diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
index 17153b5..0758656 100644
--- a/arch/arm/boot/compressed/misc.c
+++ b/arch/arm/boot/compressed/misc.c
@@ -22,6 +22,15 @@  unsigned int __machine_arch_type;
 #include linux/types.h   /* for size_t */
 #include linux/stddef.h  /* for NULL */
 #include asm/string.h
+#include asm/mach-types.h
+/* TODO:
+ * Include of this header is not working.
+ * Gives Error: undefined reference to `omap_rev'
+ * This header is needed for constant:
+ * ZOOM2_EXT_QUART_VIRT = 0xFB00
+ * ZOOM2_EXT_QUART_PHYS = 0x1000
+ */
+/* #include mach/io.h */
 
 #ifdef STANDALONE_DEBUG
 #define putstr printf
@@ -316,6 +325,103 @@  static void error(char *x)
 
 #ifndef STANDALONE_DEBUG
 
+u32  *omap_uart_debug_ll_phy_addr;
+
+static void find_debug_ll_uart_port(unsigned int arch_type)
+{
+   omap_uart_debug_ll_phy_addr = 0;
+
+   /* Add logic here for new platforms, using __macine_arch_type */
+
+   /* TODO: REVISIT -- Check Completeness
+* DEFINE PHY ADDRESS for EACH BOARD HERE: omap1/2/3/4 */
+#if defined(CONFIG_ARCH_OMAP1)
+   switch (arch_type) {
+   case MACH_TYPE_OMAP_PALMTT:
+   case MACH_TYPE_SX1:
+   /* UART2 */
+   omap_uart_debug_ll_phy_addr = (u32 *)0xfffb0800;
+   break;
+   default:
+   /* UART1 */
+   omap_uart_debug_ll_phy_addr = (u32 *)0xfffb;
+   break;
+   }
+#endif
+
+#if defined(CONFIG_ARCH_OMAP2)
+   switch (arch_type) {
+   case MACH_TYPE_NOKIA_N800:
+   case MACH_TYPE_NOKIA_N810:
+   case MACH_TYPE_NOKIA_N810_WIMAX:
+   /* UART3 */
+   omap_uart_debug_ll_phy_addr = (u32 *)0x4806e000;
+   break;
+   default:
+   /* UART1 */
+   omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
+   break;
+   }
+#endif
+
+#if defined(CONFIG_ARCH_OMAP3)
+   switch (arch_type) {
+   case MACH_TYPE_OMAP_LDP:
+   case MACH_TYPE_OVERO:
+   case MACH_TYPE_OMAP3_PANDORA:
+   case MACH_TYPE_NOKIA_RX51:
+   case MACH_TYPE_OMAP3_BEAGLE:
+   /* UART3 */
+   omap_uart_debug_ll_phy_addr = (u32 *)0x4902;
+   break

Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-09-17 Thread Russell King - ARM Linux 
On Fri, Sep 18, 2009 at 12:30:25AM +0530, Pandita, Vikram wrote:
 There are review comments by Kevin [2] still getting fixed, 
 but a 'Russell-look' will surely help to the in-lined patch [3] .

Still not good.

 + mov r9, r0
 +
 + bl  get_uart_base   @ get uart phy address
 + adr r2, __dummy
 + str r0, [r2]@save uart phy adder in memory
 + ldm r2, {r13}^  @save phyadder in usermode reg
 +
 + bl  get_uart_virt_base  @ get uart virtual address
 + adr r2, __dummy
 + str r0, [r2]@save uart phy adder in memory
 + ldm r2, {r14}^  @save phyadder in usermode reg
 +
 + mov r0, r9
 +
   bl  cache_clean_flush
   add pc, r5, r0  @ call relocation code
  
 @@ -303,6 +317,9 @@  LC0: .word   LC0 @ r1
  LC1: .word   reloc_end - reloc_start
   .size   LC0, . - LC0
  
 + .type   __dummy, #object
 +__dummy: .word   __dummy

This appears to be in the text segment, and is written to.  That's not
going to work if the text segment is stored in flash (and in fact might
be dangerous in some cases.)

 +
  #ifdef CONFIG_ARCH_RPC
   .globl  params
  params:  ldr r0, =params_phys
 diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
 index 17153b5..0758656 100644
 --- a/arch/arm/boot/compressed/misc.c
 +++ b/arch/arm/boot/compressed/misc.c
 @@ -22,6 +22,15 @@  unsigned int __machine_arch_type;
  #include linux/types.h /* for size_t */
  #include linux/stddef.h/* for NULL */
  #include asm/string.h
 +#include asm/mach-types.h
 +/* TODO:
 + * Include of this header is not working.
 + * Gives Error: undefined reference to `omap_rev'
 + * This header is needed for constant:
 + * ZOOM2_EXT_QUART_VIRT = 0xFB00
 + * ZOOM2_EXT_QUART_PHYS = 0x1000
 + */
 +/* #include mach/io.h */
  
  #ifdef STANDALONE_DEBUG
  #define putstr printf
 @@ -316,6 +325,103 @@  static void error(char *x)
  
  #ifndef STANDALONE_DEBUG
  
 +u32  *omap_uart_debug_ll_phy_addr;
 +
 +static void find_debug_ll_uart_port(unsigned int arch_type)
 +{
 + omap_uart_debug_ll_phy_addr = 0;
 +
 + /* Add logic here for new platforms, using __macine_arch_type */
 +
 + /* TODO: REVISIT -- Check Completeness
 +  * DEFINE PHY ADDRESS for EACH BOARD HERE: omap1/2/3/4 */
 +#if defined(CONFIG_ARCH_OMAP1)
 + switch (arch_type) {
 + case MACH_TYPE_OMAP_PALMTT:
 + case MACH_TYPE_SX1:
 + /* UART2 */
 + omap_uart_debug_ll_phy_addr = (u32 *)0xfffb0800;
 + break;
 + default:
 + /* UART1 */
 + omap_uart_debug_ll_phy_addr = (u32 *)0xfffb;
 + break;
 + }
 +#endif
 +
 +#if defined(CONFIG_ARCH_OMAP2)
 + switch (arch_type) {
 + case MACH_TYPE_NOKIA_N800:
 + case MACH_TYPE_NOKIA_N810:
 + case MACH_TYPE_NOKIA_N810_WIMAX:
 + /* UART3 */
 + omap_uart_debug_ll_phy_addr = (u32 *)0x4806e000;
 + break;
 + default:
 + /* UART1 */
 + omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
 + break;
 + }
 +#endif
 +
 +#if defined(CONFIG_ARCH_OMAP3)
 + switch (arch_type) {
 + case MACH_TYPE_OMAP_LDP:
 + case MACH_TYPE_OVERO:
 + case MACH_TYPE_OMAP3_PANDORA:
 + case MACH_TYPE_NOKIA_RX51:
 + case MACH_TYPE_OMAP3_BEAGLE:
 + /* UART3 */
 + omap_uart_debug_ll_phy_addr = (u32 *)0x4902;
 + break;
 + case MACH_TYPE_OMAP_ZOOM2:
 + /* EXTERNEL UART */
 + omap_uart_debug_ll_phy_addr = (u32 *)0x1000;
 + break;
 + default:
 + /* UART1 */
 + omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
 + break;
 + }
 +#endif
 +
 +#ifdef CONFIG_ARCH_OMAP4
 + switch (arch_type) {
 + /* OMAP3: UART1 */
 + case MACH_TYPE_OMAP_4430SDP:
 + default:
 + omap_uart_debug_ll_phy_addr = (u32 *)0x4806a000;
 + putstr(This is an OMAP4 ...\n);
 + break;
 + }
 +#endif
 +}
 +
 +ulg
 +get_uart_base(void)
 +{
 + return (ulg)omap_uart_debug_ll_phy_addr;
 +}
 +
 +ulg
 +get_uart_virt_base(void)
 +{
 + ulg val = 0;
 +
 +#ifdef CONFIG_ARCH_OMAP1
 + /* omap1 */
 + val = 0xfef0;
 +#else
 + /* omap2/3/4... */
 + if (MACH_TYPE_OMAP_ZOOM2 == __machine_arch_type)
 + val = 0xFB00; /* ZOOM2_EXT_QUART_VIRT */
 + else
 + val = 0xd800;
 +#endif
 +
 + return (ulg)(((val)  18)  0xfffc);
 +}
 +

Clearly, all this code should not be in here.  There's a perfectly good
header file to contain the platform specifics which it can live in, and
there's a perfectly good hook for it to latch into (arch_decomp_setup).

 diff --git

Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-09-16 Thread Russell King - ARM Linux 
On Thu, Aug 27, 2009 at 04:29:35PM +0300, Kevin Hilman wrote:
  The idea is to write to phys_io and io_pg_offset from kernel/head.S
  very early based on the uart address found in compressed/misc.c
 
  To make map_io writable, I will have to change the MACHINE_START to
  remove the const.  It so happens that Russell has defined
  MACHINE_START to be a const.
 
  Not sure is removing const from MACHINE_START is acceptable?
 
 we'll find out after you post for RFC.

The answer is no, it is not acceptable - it'll break XIP kernels
because this is placed into the read-only part of the kernel image
no matter what.
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Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-27 Thread Kevin Hilman 
Pandita, Vikram vikram.pand...@ti.com writes:

Vikram Pandita wrote:
 This patch cleans up the DEBUG_LL infrastructure for omap boards.

Thanks Vikram, this is indeed in need of some cleanup.  But I have some
comments about the approach taken.

This approach still doesn't solve one of the fundamental problems with
the current implementation.  It prevents using a single kernel across
multiple boards.  If we could drop the compile-time decision in favor of
a runtime one based on machine-type, we could use a single base
defconfig that would be able to be tested on all omap3 boards for example.

For the zImage UART output (uncompress.h) there is a global variable
__machine_arch_type which could be used to check the board type and set
variable for UART base and shift.  We do this on DaVinci.

 Could you give reference to this code on DaVinci?

http://git.kernel.org/?p=linux/kernel/git/khilman/linux-davinci.git;a=blobdiff;f=arch/arm/mach-davinci/include/mach/uncompress.h;h=0f1f12b67875f86232c0e06e1a687a6d7f19b18a;hp=1e27475f9a2322f1a4f61e25fd1a1e5858e29fc2;hb=bb9647f44b091ebff17f400bb2a468c7e419f3ac;hpb=0dc6306a65f30c0483cfed9b3e8ee1eb3d093e84


 Yes this is doable, but the question is, how do we pass these variables to 
 the kernel start:
 arch/arm/kernel/head.S

 First stage, arch/arm/boot/compressed/head.S gets the arch type - 
 shift/uart-addr. Fine.
 This stage ends with relocated code over righting the decompressor.

 Second stage, arch/arm/kernel/head.S now starts.

 I am not sure how to share the data from Stage 1 in this stage?

This is already taken care of.

The zImage boot passes the machine-type in a register, then
arch/arm/kernel/head.S uses that to decide which machine to start. 
This is where the MACHINE_START/MACHINE_END macros come in to
define the machine-specific hooks called at boot time.

You should use one of the early machine hooks (probably .map_io)
to to set the UART base and shift for the board.

The catch is that between the start of the head.S code and the
mach-map_io hook, printascii() may be called and use the debug
macros to try to print out chars.  Care must be taken that
if the UART is not yet known/defined, nothing is printed.

Kevin

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RE: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-27 Thread Pandita, Vikram 


-Original Message-
From: Kevin Hilman [mailto:khil...@deeprootsystems.com]
Pandita, Vikram vikram.pand...@ti.com writes:

Vikram Pandita wrote:
 This patch cleans up the DEBUG_LL infrastructure for omap boards.


 Could you give reference to this code on DaVinci?

http://git.kernel.org/?p=linux/kernel/git/khilman/linux-davinci.git;a=blobdiff;f=arch/arm/mach-
davinci/include/mach/uncompress.h;h=0f1f12b67875f86232c0e06e1a687a6d7f19b18a;hp=1e27475f9a2322f1a4f61
e25fd1a1e5858e29fc2;hb=bb9647f44b091ebff17f400bb2a468c7e419f3ac;hpb=0dc6306a65f30c0483cfed9b3e8ee1eb3
d093e84


 Yes this is doable, but the question is, how do we pass these variables to 
 the kernel start:
 arch/arm/kernel/head.S

 First stage, arch/arm/boot/compressed/head.S gets the arch type - 
 shift/uart-addr. Fine.
 This stage ends with relocated code over righting the decompressor.

 Second stage, arch/arm/kernel/head.S now starts.

 I am not sure how to share the data from Stage 1 in this stage?

This is already taken care of.

The zImage boot passes the machine-type in a register, then
arch/arm/kernel/head.S uses that to decide which machine to start.
This is where the MACHINE_START/MACHINE_END macros come in to
define the machine-specific hooks called at boot time.

Yes. I agree. I have reviewed that path.


You should use one of the early machine hooks (probably .map_io)
to to set the UART base and shift for the board.

I am looking at even earlier than that.

The idea is to write to phys_io and io_pg_offset from kernel/head.S very early 
based on the uart address found in compressed/misc.c 

To make map_io writable, I will have to change the MACHINE_START to remove the 
const.
It so happens that Russell has defined MACHINE_START to be a const.

Not sure is removing const from MACHINE_START is acceptable?

I can have a sample implementation and post to get review comments.


The catch is that between the start of the head.S code and the
mach-map_io hook, printascii() may be called and use the debug
macros to try to print out chars.  Care must be taken that
if the UART is not yet known/defined, nothing is printed.

That is easy and can be taken care of.


Kevin


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Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-27 Thread Kevin Hilman 
Pandita, Vikram vikram.pand...@ti.com writes:

-Original Message-
From: Kevin Hilman [mailto:khil...@deeprootsystems.com]
Pandita, Vikram vikram.pand...@ti.com writes:

Vikram Pandita wrote:
 This patch cleans up the DEBUG_LL infrastructure for omap boards.

 Could you give reference to this code on DaVinci?

http://git.kernel.org/?p=linux/kernel/git/khilman/linux-davinci.git;a=blobdiff;f=arch/arm/mach-
davinci/include/mach/uncompress.h;h=0f1f12b67875f86232c0e06e1a687a6d7f19b18a;hp=1e27475f9a2322f1a4f61
e25fd1a1e5858e29fc2;hb=bb9647f44b091ebff17f400bb2a468c7e419f3ac;hpb=0dc6306a65f30c0483cfed9b3e8ee1eb3
d093e84

 Yes this is doable, but the question is, how do we pass these
 variables to the kernel start: arch/arm/kernel/head.S
 First stage, arch/arm/boot/compressed/head.S gets the arch type -
 shift/uart-addr. Fine.  This stage ends with relocated code over
 righting the decompressor.
 Second stage, arch/arm/kernel/head.S now starts.
 I am not sure how to share the data from Stage 1 in this stage?

This is already taken care of.

The zImage boot passes the machine-type in a register, then
arch/arm/kernel/head.S uses that to decide which machine to start.
This is where the MACHINE_START/MACHINE_END macros come in to
define the machine-specific hooks called at boot time.

 Yes. I agree. I have reviewed that path.


You should use one of the early machine hooks (probably .map_io)
to to set the UART base and shift for the board.

 I am looking at even earlier than that.

OK

 The idea is to write to phys_io and io_pg_offset from kernel/head.S
 very early based on the uart address found in compressed/misc.c

 To make map_io writable, I will have to change the MACHINE_START to
 remove the const.  It so happens that Russell has defined
 MACHINE_START to be a const.

 Not sure is removing const from MACHINE_START is acceptable?

we'll find out after you post for RFC.

 I can have a sample implementation and post to get review comments.


The catch is that between the start of the head.S code and the
mach-map_io hook, printascii() may be called and use the debug
macros to try to print out chars.  Care must be taken that
if the UART is not yet known/defined, nothing is printed.

 That is easy and can be taken care of.


ok, I look forward to seeing how you handle this.

Kevin

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RE: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-26 Thread Pandita, Vikram 
Kevin

-Original Message-
From: Kevin Hilman [mailto:khil...@deeprootsystems.com]
Sent: Saturday, August 22, 2009 2:57 AM
To: Pandita, Vikram
Cc: linux-omap@vger.kernel.org; linux-arm-ker...@lists.arm.linux.org.uk
Subject: Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

Vikram Pandita wrote:
 This patch cleans up the DEBUG_LL infrastructure for omap boards.

Thanks Vikram, this is indeed in need of some cleanup.  But I have some
comments about the approach taken.

This approach still doesn't solve one of the fundamental problems with
the current implementation.  It prevents using a single kernel across
multiple boards.  If we could drop the compile-time decision in favor of
a runtime one based on machine-type, we could use a single base
defconfig that would be able to be tested on all omap3 boards for example.

For the zImage UART output (uncompress.h) there is a global variable
__machine_arch_type which could be used to check the board type and set
variable for UART base and shift.  We do this on DaVinci.

Could you give reference to this code on DaVinci?

Yes this is doable, but the question is, how do we pass these variables to the 
kernel start:
arch/arm/kernel/head.S

First stage, arch/arm/boot/compressed/head.S gets the arch type - 
shift/uart-addr. Fine.
This stage ends with relocated code over righting the decompressor.

Second stage, arch/arm/kernel/head.S now starts.

I am not sure how to share the data from Stage 1 in this stage?


For debug output (debug-macro.S) those macros should be changed to use
variables for UART base and shift also.  While you're in changing the
board files, you could also add something like this to each:

#ifdef CONFIG_SERIAL_8250_CONSOLE
static int __init board_console_init(void)
{
   return add_preferred_console(ttyS, UART#, 115200);
}
console_initcall(board_console_init);
#endif

This also allows the board to boot using a default UART even without
having the console= on the cmdline.

There is one catch to doing this at runtime instead of compile time.
The variables for the UART base and shift have to be set very early in
the boot, otherwise any errors from the early ARM asm boot (head.S) will
be missed.

For starters, they could be assingned in the board map_io hook, but we'd
still miss the debug prints if there were any errors parsing the
machine_type and processor_type early in the boot (head.S)

I'd be ok with this limitation for a first pass because it's still
better than what we currently have in l-o, but I'd like to hear if
others had some ideas for how we might do dynamic decisions on UART
based on board-type very early in the boot.

Kevin

 The three stages of log printing infrastructure is using their own #defines
 The patch integrates the three stages to use the same variable.

 Three stages are:
 Stage 1: Prints - Uncompressing Linux..
  File getting used: arch/arm/plat-omap/include/mach/uncompress.h
 Stage 2: Prints - 5Linux version 2.6.31
  File getting used: arch/arm/plat-omap/include/mach/debug-macro.S
 Stage 3: Kernel ttyS console takes over

 On enabling the DEBUG_LL menuconfig item
 [Kernel Hacking - Kernel low-level debugging functions]

 the following entry gets auto selected
 [Systerm Type - TI OMAP Implementations - Low-level Debug console UART]

 This is the physical address of the UART getting used for the board.
 The physical address of debug uart is provided as a menuconfig option now.

 Issue with current system:
 (a) Zoom2 board has a detachable debug board having the TL16CP754 Quad uart 
 chip.
 If the debug board is not attached, _NO_ debug uart is available.
 OMAP internal uarts are not used for traces on zoom2 board.
 Current framework does not account for boards that may not have a debug uart
 at all. The Stage 1 always accesses one of the uarts. Thats fixed now.

 (b) this patch does a cleanup of 
 arch/arm/plat-omap/include/mach/debug-macro.S

 Signed-off-by: Vikram Pandita vikram.pand...@ti.com
 ---
  arch/arm/plat-omap/Kconfig|   50 
 ++---
  arch/arm/plat-omap/include/mach/common.h  |7 +++
  arch/arm/plat-omap/include/mach/debug-macro.S |   40 
  arch/arm/plat-omap/include/mach/uncompress.h  |   12 +
  4 files changed, 54 insertions(+), 55 deletions(-)

 diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
 index ab9f9ef..2fefb64 100644
 --- a/arch/arm/plat-omap/Kconfig
 +++ b/arch/arm/plat-omap/Kconfig
 @@ -162,21 +162,43 @@ config OMAP_DM_TIMER
  help
   Select this option if you want to use OMAP Dual-Mode timers.

 -choice
 -prompt Low-level debug console UART
 -depends on ARCH_OMAP
 -default OMAP_LL_DEBUG_UART1
 -
 -config OMAP_LL_DEBUG_UART1
 -bool UART1
 -
 -config OMAP_LL_DEBUG_UART2
 -bool UART2

 -config OMAP_LL_DEBUG_UART3
 -bool UART3
 -
 -endchoice
 +config OMAP_DEBUG_LL_UART_PHY_ADDR
 +hex Low-level debug console UART Physical Address
 +depends on ARCH_OMAP  DEBUG_LL

Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-24 Thread Tony Lindgren 
* Kevin Hilman khil...@deeprootsystems.com [090822 16:31]:
 Vikram Pandita wrote:
 This patch cleans up the DEBUG_LL infrastructure for omap boards.

 Thanks Vikram, this is indeed in need of some cleanup.  But I have some
 comments about the approach taken.

 This approach still doesn't solve one of the fundamental problems with
 the current implementation.  It prevents using a single kernel across
 multiple boards.  If we could drop the compile-time decision in favor of
 a runtime one based on machine-type, we could use a single base
 defconfig that would be able to be tested on all omap3 boards for example.

 For the zImage UART output (uncompress.h) there is a global variable
 __machine_arch_type which could be used to check the board type and set
 variable for UART base and shift.  We do this on DaVinci.

I agree we should do this.


 For debug output (debug-macro.S) those macros should be changed to use
 variables for UART base and shift also.  While you're in changing the
 board files, you could also add something like this to each:

 #ifdef CONFIG_SERIAL_8250_CONSOLE
 static int __init board_console_init(void)
 {
   return add_preferred_console(ttyS, UART#, 115200);
 }
 console_initcall(board_console_init);
 #endif

 This also allows the board to boot using a default UART even without
 having the console= on the cmdline.

 There is one catch to doing this at runtime instead of compile time.
 The variables for the UART base and shift have to be set very early in
 the boot, otherwise any errors from the early ARM asm boot (head.S) will
 be missed.

 For starters, they could be assingned in the board map_io hook, but we'd
 still miss the debug prints if there were any errors parsing the
 machine_type and processor_type early in the boot (head.S)

 I'd be ok with this limitation for a first pass because it's still
 better than what we currently have in l-o, but I'd like to hear if
 others had some ideas for how we might do dynamic decisions on UART
 based on board-type very early in the boot.

Yup, good comments.

Tony


 Kevin

 The three stages of log printing infrastructure is using their own #defines
 The patch integrates the three stages to use the same variable.

 Three stages are:
 Stage 1: Prints - Uncompressing Linux..
  File getting used: arch/arm/plat-omap/include/mach/uncompress.h
 Stage 2: Prints - 5Linux version 2.6.31
  File getting used: arch/arm/plat-omap/include/mach/debug-macro.S
 Stage 3: Kernel ttyS console takes over

 On enabling the DEBUG_LL menuconfig item
 [Kernel Hacking - Kernel low-level debugging functions]

 the following entry gets auto selected
 [Systerm Type - TI OMAP Implementations - Low-level Debug console UART]

 This is the physical address of the UART getting used for the board.
 The physical address of debug uart is provided as a menuconfig option now.

 Issue with current system:
 (a) Zoom2 board has a detachable debug board having the TL16CP754 Quad uart 
 chip.
 If the debug board is not attached, _NO_ debug uart is available.
 OMAP internal uarts are not used for traces on zoom2 board.
 Current framework does not account for boards that may not have a debug uart
 at all. The Stage 1 always accesses one of the uarts. Thats fixed now.

 (b) this patch does a cleanup of 
 arch/arm/plat-omap/include/mach/debug-macro.S

 Signed-off-by: Vikram Pandita vikram.pand...@ti.com
 ---
  arch/arm/plat-omap/Kconfig|   50 
 ++---
  arch/arm/plat-omap/include/mach/common.h  |7 +++
  arch/arm/plat-omap/include/mach/debug-macro.S |   40 
  arch/arm/plat-omap/include/mach/uncompress.h  |   12 +
  4 files changed, 54 insertions(+), 55 deletions(-)

 diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
 index ab9f9ef..2fefb64 100644
 --- a/arch/arm/plat-omap/Kconfig
 +++ b/arch/arm/plat-omap/Kconfig
 @@ -162,21 +162,43 @@ config OMAP_DM_TIMER
  help
   Select this option if you want to use OMAP Dual-Mode timers.
  -choice
 -prompt Low-level debug console UART
 -depends on ARCH_OMAP
 -default OMAP_LL_DEBUG_UART1
 -
 -config OMAP_LL_DEBUG_UART1
 -bool UART1
 -
 -config OMAP_LL_DEBUG_UART2
 -bool UART2
  -config OMAP_LL_DEBUG_UART3
 -bool UART3
 -
 -endchoice
 +config OMAP_DEBUG_LL_UART_PHY_ADDR
 +hex Low-level debug console UART Physical Address
 +depends on ARCH_OMAP  DEBUG_LL
 +
 +default 0xfffb0800 if ARCH_OMAP1  (MACH_OMAP_PALMTT || MACH_SX1)
 +default 0xfffb if ARCH_OMAP1
 +default 0x4806e000 if ARCH_OMAP2  MACH_NOKIA_N8X0
 +default 0x4806a000 if ARCH_OMAP2
 +default 0x4902 if ARCH_OMAP3  (MACH_NOKIA_RX51 || 
 MACH_OMAP_BEAGLE)
 +default 0x4902 if ARCH_OMAP3  (MACH_OMAP3_PANDORA || 
 MACH_OMAP_LDP || MACH_OVERO)
 +default 0x1000 if ARCH_OMAP3  MACH_OMAP_ZOOM2
 +default 0x4806a000 if ARCH_OMAP3
 +default 0x4806a000 if ARCH_OMAP4
 +help
 +  Specify the Physical address of Low

RE: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-22 Thread Shilimkar, Santosh 
Vikram,
Thanks for this clean-up series !!
Couple of comments.

snip snip
 -Original Message-
 From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap-
 ow...@vger.kernel.org] On Behalf Of Pandita, Vikram
 Sent: Friday, August 21, 2009 11:25 PM
 To: linux-omap@vger.kernel.org; linux-arm-ker...@lists.arm.linux.org.uk
 Cc: Pandita, Vikram
 Subject: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup
 
of arch/arm/plat-omap/include/mach/debug-
 macro.S
 
 Signed-off-by: Vikram Pandita vikram.pand...@ti.com
 ---
  arch/arm/plat-omap/Kconfig|   50 ++--
 -
  arch/arm/plat-omap/include/mach/common.h  |7 +++
  arch/arm/plat-omap/include/mach/debug-macro.S |   40 
  arch/arm/plat-omap/include/mach/uncompress.h  |   12 +
  4 files changed, 54 insertions(+), 55 deletions(-)
 
 diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
 index ab9f9ef..2fefb64 100644
 --- a/arch/arm/plat-omap/Kconfig
 +++ b/arch/arm/plat-omap/Kconfig
 @@ -162,21 +162,43 @@ config OMAP_DM_TIMER
   help
Select this option if you want to use OMAP Dual-Mode timers.
 
 
 +   Specify the Physical address of Low level debug UART
 +   Specify 0x0 in case you do not want DEBUG_LL functions to iterfere
 with your board uarts
 +
 +   OMAP1:
 +   ---
 +   UART1 - 0xfffb (default)
 +   UART2 - 0xfffb0800
 +   UART3 - 0xfffb9800 (sx1, palmtt)
 +
 +   OMAP2:
 +   ---
 +   UART1 - 0x4806a000 (default)
 +   UART2 - 0x4806c000
 +   UART3 - 0x4806e000 (N8X0)
 +
 +   OMAP3/4:
 +   ---
 +   UART1 - 0x4806a000 (default: except following)
 +   UART2 - 0x4806c000
 +   UART3 - 0x4902 (rx51, beagle, pendora, ldp, overo)

OMAP4 UART3 base address is 0x4802

 +   UART4 - 0x4806e000
 +   UART_EXT  - 0x1000 (zoom2: Debug uart is on external debug
 board)
 

 -
 -#elif defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
 - moveq   \rx, #0x4800@ physical base address
 - movne   \rx, #0xd800@ virtual base
 - orr \rx, \rx, #0x0006a000
 -#ifdef CONFIG_OMAP_LL_DEBUG_UART2
 - add \rx, \rx, #0x2000   @ UART 2
 -#endif
 -#ifdef CONFIG_OMAP_LL_DEBUG_UART3
 - add \rx, \rx, #0x00fb   @ UART 3
This was already wrong for OMAP4
 - add \rx, \rx, #0x6000
 -#endif
 + /* omap1 */
 + ldr \rx, =CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR @ physical base
 address
 + subne   \rx, #CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR,
 #OMAP1_IO_OFFSET @ virtual base
 +#else
 + /* omap2/omap3/omap4 */
 + ldr \rx, =CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR @ physical base
 address
 + orrne   \rx, \rx, #OMAP2_IO_OFFSET   @ virtual base
  #endif
   .endm
 
 diff --git a/arch/arm/plat-omap/include/mach/uncompress.h b/arch/arm/plat-
 omap/include/mach/uncompress.h
 index 0814c5f..0e21eb3 100644
 --- a/arch/arm/plat-omap/include/mach/uncompress.h
 +++ b/arch/arm/plat-omap/include/mach/uncompress.h
 @@ -38,14 +38,8 @@ static void putc(int c)
   return;
  #endif
 
 -#ifdef CONFIG_ARCH_OMAP
 -#ifdef   CONFIG_OMAP_LL_DEBUG_UART3
 - uart = (volatile u8 *)(OMAP_UART3_BASE);
 -#elif defined(CONFIG_OMAP_LL_DEBUG_UART2)
 - uart = (volatile u8 *)(OMAP_UART2_BASE);
 -#else
 - uart = (volatile u8 *)(OMAP_UART1_BASE);
 -#endif
 +#if defined(CONFIG_DEBUG_LL)
 + uart = (volatile u8 *)(CONFIG_OMAP_DEBUG_LL_UART_PHY_ADDR);
 
  #ifdef CONFIG_ARCH_OMAP1
   /* Determine which serial port to use */
 @@ -62,7 +56,6 @@ static void putc(int c)
   return;
   } while (0);
  #endif /* CONFIG_ARCH_OMAP1 */
 -#endif
 

Regards,
Santosh
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Re: [PATCH 1/5] OMAP1/2/3/4: DEBUG_LL: cleanup

2009-08-22 Thread Kevin Hilman 

Vikram Pandita wrote:

This patch cleans up the DEBUG_LL infrastructure for omap boards.


Thanks Vikram, this is indeed in need of some cleanup.  But I have some
comments about the approach taken.

This approach still doesn't solve one of the fundamental problems with
the current implementation.  It prevents using a single kernel across
multiple boards.  If we could drop the compile-time decision in favor of
a runtime one based on machine-type, we could use a single base
defconfig that would be able to be tested on all omap3 boards for example.

For the zImage UART output (uncompress.h) there is a global variable
__machine_arch_type which could be used to check the board type and set
variable for UART base and shift.  We do this on DaVinci.

For debug output (debug-macro.S) those macros should be changed to use
variables for UART base and shift also.  While you're in changing the
board files, you could also add something like this to each:

#ifdef CONFIG_SERIAL_8250_CONSOLE
static int __init board_console_init(void)
{
return add_preferred_console(ttyS, UART#, 115200);
}
console_initcall(board_console_init);
#endif

This also allows the board to boot using a default UART even without
having the console= on the cmdline.

There is one catch to doing this at runtime instead of compile time.
The variables for the UART base and shift have to be set very early in
the boot, otherwise any errors from the early ARM asm boot (head.S) will
be missed.

For starters, they could be assingned in the board map_io hook, but we'd
still miss the debug prints if there were any errors parsing the
machine_type and processor_type early in the boot (head.S)

I'd be ok with this limitation for a first pass because it's still
better than what we currently have in l-o, but I'd like to hear if
others had some ideas for how we might do dynamic decisions on UART
based on board-type very early in the boot.

Kevin


The three stages of log printing infrastructure is using their own #defines
The patch integrates the three stages to use the same variable.

Three stages are:
Stage 1: Prints - Uncompressing Linux..
File getting used: arch/arm/plat-omap/include/mach/uncompress.h
Stage 2: Prints - 5Linux version 2.6.31
File getting used: arch/arm/plat-omap/include/mach/debug-macro.S
Stage 3: Kernel ttyS console takes over

On enabling the DEBUG_LL menuconfig item
[Kernel Hacking - Kernel low-level debugging functions]

the following entry gets auto selected
[Systerm Type - TI OMAP Implementations - Low-level Debug console UART]

This is the physical address of the UART getting used for the board.
The physical address of debug uart is provided as a menuconfig option now.

Issue with current system:
(a) Zoom2 board has a detachable debug board having the TL16CP754 Quad uart 
chip.
If the debug board is not attached, _NO_ debug uart is available.
OMAP internal uarts are not used for traces on zoom2 board.
Current framework does not account for boards that may not have a debug uart
at all. The Stage 1 always accesses one of the uarts. Thats fixed now.

(b) this patch does a cleanup of arch/arm/plat-omap/include/mach/debug-macro.S

Signed-off-by: Vikram Pandita vikram.pand...@ti.com
---
 arch/arm/plat-omap/Kconfig|   50 ++---
 arch/arm/plat-omap/include/mach/common.h  |7 +++
 arch/arm/plat-omap/include/mach/debug-macro.S |   40 
 arch/arm/plat-omap/include/mach/uncompress.h  |   12 +
 4 files changed, 54 insertions(+), 55 deletions(-)

diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index ab9f9ef..2fefb64 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -162,21 +162,43 @@ config OMAP_DM_TIMER
help
 Select this option if you want to use OMAP Dual-Mode timers.
 
-choice

-   prompt Low-level debug console UART
-   depends on ARCH_OMAP
-   default OMAP_LL_DEBUG_UART1
-
-config OMAP_LL_DEBUG_UART1
-   bool UART1
-
-config OMAP_LL_DEBUG_UART2
-   bool UART2
 
-config OMAP_LL_DEBUG_UART3

-   bool UART3
-
-endchoice
+config OMAP_DEBUG_LL_UART_PHY_ADDR
+   hex Low-level debug console UART Physical Address
+   depends on ARCH_OMAP  DEBUG_LL
+
+   default 0xfffb0800 if ARCH_OMAP1  (MACH_OMAP_PALMTT || MACH_SX1)
+   default 0xfffb if ARCH_OMAP1
+   default 0x4806e000 if ARCH_OMAP2  MACH_NOKIA_N8X0
+   default 0x4806a000 if ARCH_OMAP2
+   default 0x4902 if ARCH_OMAP3  (MACH_NOKIA_RX51 || 
MACH_OMAP_BEAGLE)
+   default 0x4902 if ARCH_OMAP3  (MACH_OMAP3_PANDORA || 
MACH_OMAP_LDP || MACH_OVERO)
+   default 0x1000 if ARCH_OMAP3  MACH_OMAP_ZOOM2
+   default 0x4806a000 if ARCH_OMAP3
+   default 0x4806a000 if ARCH_OMAP4
+   help
+ Specify the Physical address of Low level debug UART
+ Specify 0x0 in case you do not want DEBUG_LL functions to iterfere 
with your board uarts
+
+ OMAP1:
+