Patchwork [RFC,v4,2/2] powerpc: gamecube/wii: early debugging using usbgecko

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Submitter Albert Herranz
Date Dec. 3, 2009, 8:35 p.m.
Message ID <4f4baca1cd65f7949610ca901c9a8bcb1bb74cfd.1259871725.git.albert_herranz@yahoo.es>
Download mbox | patch
Permalink /patch/40242/
State Superseded
Headers show

Comments

Albert Herranz - Dec. 3, 2009, 8:35 p.m.
Add support for using the USB Gecko adapter as an early debugging
console on the Nintendo GameCube and Wii video game consoles.
The USB Gecko is a 3rd party memory card interface adapter that provides
a EXI (External Interface) to USB serial converter.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
---
 arch/powerpc/Kconfig.debug                         |    8 +++
 arch/powerpc/include/asm/udbg.h                    |    1 +
 arch/powerpc/kernel/head_32.S                      |   25 +++++++++
 arch/powerpc/kernel/udbg.c                         |    2 +
 arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c |   56 ++++++++++++++++++++
 arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h |    2 +
 6 files changed, 94 insertions(+), 0 deletions(-)
Segher Boessenkool - Dec. 4, 2009, 12:04 p.m.
> +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
> +setup_usbgecko_bat:
> +	/* prepare a BAT for early io */
> +#if defined(CONFIG_GAMECUBE)
> +	lis	r8, 0x0c00
> +#elif defined(CONFIG_WII)
> +	lis	r8, 0x0d00
> +#else
> +#error Invalid platform for USB Gecko based early debugging.
> +#endif

A kernel with both CONFIG_WII and CONFIG_GAMECUBE works fine
on either, right?  If so, could you please switch the two #ifs?
A dual-platform kernel will be used on a Wii much more likely
than on a GC.

> +	/*
> +	 * The virtual address used must match the virtual address
> +	 * associated to the fixmap entry FIX_EARLY_DEBUG_BASE.
> +	 */
> +	lis	r11, 0xfffe	/* top 128K */
> +	ori	r8, r8, 0x002a	/* uncached, guarded ,rw */
> +	ori	r11, r11, 0x3	/* 128K */

I think you should clear Vp since the BAT mapping can survive until
after user space is started; it won't hurt to remove it either way.
So 2 instead of 3.  And put the meaning in the comment :-)

Looks fine otherwise.


Segher
Albert Herranz - Dec. 4, 2009, 4:54 p.m.
Segher Boessenkool wrote:
>> +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
>> +setup_usbgecko_bat:
>> +    /* prepare a BAT for early io */
>> +#if defined(CONFIG_GAMECUBE)
>> +    lis    r8, 0x0c00
>> +#elif defined(CONFIG_WII)
>> +    lis    r8, 0x0d00
>> +#else
>> +#error Invalid platform for USB Gecko based early debugging.
>> +#endif
> 
> A kernel with both CONFIG_WII and CONFIG_GAMECUBE works fine
> on either, right?  If so, could you please switch the two #ifs?
> A dual-platform kernel will be used on a Wii much more likely
> than on a GC.
> 

Nope, a GameCube kernel currently doesn't work on a Wii and the same the other way around.

But I can make that particular check a runtime check.
The idea would be to enclose that snippet in GAMECUBE_COMMON and check the PVR. If it is a Gekko (a fixed value) then we have a GameCube, otherwise we assume a Wii.

>> +    /*
>> +     * The virtual address used must match the virtual address
>> +     * associated to the fixmap entry FIX_EARLY_DEBUG_BASE.
>> +     */
>> +    lis    r11, 0xfffe    /* top 128K */
>> +    ori    r8, r8, 0x002a    /* uncached, guarded ,rw */
>> +    ori    r11, r11, 0x3    /* 128K */
> 
> I think you should clear Vp since the BAT mapping can survive until
> after user space is started; it won't hurt to remove it either way.
> So 2 instead of 3.  And put the meaning in the comment :-)

This BAT is re-setup again on MMU_init, way before starting userspace.
But I'll make it Vs=1, Vp=0 here too :)

> 
> Looks fine otherwise.
> 

Thanks.

> 
> Segher
> 
> 

Cheers,
Albert
Segher Boessenkool - Dec. 4, 2009, 7:56 p.m.
>>> +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
>>> +setup_usbgecko_bat:
>>> +    /* prepare a BAT for early io */
>>> +#if defined(CONFIG_GAMECUBE)
>>> +    lis    r8, 0x0c00
>>> +#elif defined(CONFIG_WII)
>>> +    lis    r8, 0x0d00
>>> +#else
>>> +#error Invalid platform for USB Gecko based early debugging.
>>> +#endif
>>
>> A kernel with both CONFIG_WII and CONFIG_GAMECUBE works fine
>> on either, right?  If so, could you please switch the two #ifs?
>> A dual-platform kernel will be used on a Wii much more likely
>> than on a GC.
>
> Nope, a GameCube kernel currently doesn't work on a Wii and the same the
> other way around.

What is the problem, just the wrappers?

> But I can make that particular check a runtime check.

Nah, don't bother, this is just early debug stuff.

> The idea would be to enclose that snippet in GAMECUBE_COMMON and check the
> PVR.

Ugly!


Segher
Benjamin Herrenschmidt - Dec. 11, 2009, 10:16 p.m.
On Thu, 2009-12-03 at 21:35 +0100, Albert Herranz wrote:
> Add support for using the USB Gecko adapter as an early debugging
> console on the Nintendo GameCube and Wii video game consoles.
> The USB Gecko is a 3rd party memory card interface adapter that provides
> a EXI (External Interface) to USB serial converter.
> 
> Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

> ---
>  arch/powerpc/Kconfig.debug                         |    8 +++
>  arch/powerpc/include/asm/udbg.h                    |    1 +
>  arch/powerpc/kernel/head_32.S                      |   25 +++++++++
>  arch/powerpc/kernel/udbg.c                         |    2 +
>  arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c |   56 ++++++++++++++++++++
>  arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h |    2 +
>  6 files changed, 94 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
> index 3b10051..11e385b 100644
> --- a/arch/powerpc/Kconfig.debug
> +++ b/arch/powerpc/Kconfig.debug
> @@ -254,6 +254,14 @@ config PPC_EARLY_DEBUG_CPM
>  	  using a CPM-based serial port.  This assumes that the bootwrapper
>  	  has run, and set up the CPM in a particular way.
>  
> +config PPC_EARLY_DEBUG_USBGECKO
> +	bool "Early debugging through the USB Gecko adapter"
> +	depends on GAMECUBE_COMMON
> +	select USBGECKO_UDBG
> +	help
> +	  Select this to enable early debugging for Nintendo GameCube/Wii
> +	  consoles via an external USB Gecko adapter.
> +
>  endchoice
>  
>  config PPC_EARLY_DEBUG_44x_PHYSLOW
> diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h
> index cd21e5e..11ae699 100644
> --- a/arch/powerpc/include/asm/udbg.h
> +++ b/arch/powerpc/include/asm/udbg.h
> @@ -51,6 +51,7 @@ extern void __init udbg_init_btext(void);
>  extern void __init udbg_init_44x_as1(void);
>  extern void __init udbg_init_40x_realmode(void);
>  extern void __init udbg_init_cpm(void);
> +extern void __init udbg_init_usbgecko(void);
>  
>  #endif /* __KERNEL__ */
>  #endif /* _ASM_POWERPC_UDBG_H */
> diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
> index 829c3fe..00b89c0 100644
> --- a/arch/powerpc/kernel/head_32.S
> +++ b/arch/powerpc/kernel/head_32.S
> @@ -164,6 +164,9 @@ __after_mmu_off:
>  #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
>  	bl	setup_cpm_bat
>  #endif
> +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
> +	bl	setup_usbgecko_bat
> +#endif
>  
>  /*
>   * Call setup_cpu for CPU 0 and initialize 6xx Idle
> @@ -1203,6 +1206,28 @@ setup_cpm_bat:
>  	blr
>  #endif
>  
> +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
> +setup_usbgecko_bat:
> +	/* prepare a BAT for early io */
> +#if defined(CONFIG_GAMECUBE)
> +	lis	r8, 0x0c00
> +#elif defined(CONFIG_WII)
> +	lis	r8, 0x0d00
> +#else
> +#error Invalid platform for USB Gecko based early debugging.
> +#endif
> +	/*
> +	 * The virtual address used must match the virtual address
> +	 * associated to the fixmap entry FIX_EARLY_DEBUG_BASE.
> +	 */
> +	lis	r11, 0xfffe	/* top 128K */
> +	ori	r8, r8, 0x002a	/* uncached, guarded ,rw */
> +	ori	r11, r11, 0x3	/* 128K */
> +	mtspr	SPRN_DBAT1L, r8
> +	mtspr	SPRN_DBAT1U, r11
> +	blr
> +#endif
> +
>  #ifdef CONFIG_8260
>  /* Jump into the system reset for the rom.
>   * We first disable the MMU, and then jump to the ROM reset address.
> diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
> index fc9af47..e39cad8 100644
> --- a/arch/powerpc/kernel/udbg.c
> +++ b/arch/powerpc/kernel/udbg.c
> @@ -60,6 +60,8 @@ void __init udbg_early_init(void)
>  	udbg_init_40x_realmode();
>  #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
>  	udbg_init_cpm();
> +#elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
> +	udbg_init_usbgecko();
>  #endif
>  
>  #ifdef CONFIG_PPC_EARLY_DEBUG
> diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
> index ba4c7cc..edc956c 100644
> --- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
> +++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
> @@ -17,6 +17,7 @@
>  #include <asm/io.h>
>  #include <asm/prom.h>
>  #include <asm/udbg.h>
> +#include <asm/fixmap.h>
>  
>  #include "usbgecko_udbg.h"
>  
> @@ -270,3 +271,58 @@ done:
>  		of_node_put(np);
>  	return;
>  }
> +
> +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
> +
> +static phys_addr_t __init ug_early_grab_io_addr(void)
> +{
> +#if defined(CONFIG_GAMECUBE)
> +	return 0x0c000000;
> +#elif defined(CONFIG_WII)
> +	return 0x0d000000;
> +#else
> +#error Invalid platform for USB Gecko based early debugging.
> +#endif
> +}
> +
> +/*
> + * USB Gecko early debug support initialization for udbg.
> + */
> +void __init udbg_init_usbgecko(void)
> +{
> +	void __iomem *early_debug_area;
> +	void __iomem *exi_io_base;
> +
> +	/*
> +	 * At this point we have a BAT already setup that enables I/O
> +	 * to the EXI hardware.
> +	 *
> +	 * The BAT uses a virtual address range reserved at the fixmap.
> +	 * This must match the virtual address configured in
> +	 * head_32.S:setup_usbgecko_bat().
> +	 */
> +	early_debug_area = (void __iomem *)__fix_to_virt(FIX_EARLY_DEBUG_BASE);
> +	exi_io_base = early_debug_area + 0x00006800;
> +
> +	/* try to detect a USB Gecko */
> +	if (!ug_udbg_probe(exi_io_base))
> +		return;
> +
> +	/* we found a USB Gecko, load udbg hooks */
> +	udbg_putc = ug_udbg_putc;
> +	udbg_getc = ug_udbg_getc;
> +	udbg_getc_poll = ug_udbg_getc_poll;
> +
> +	/*
> +	 * Prepare again the same BAT for MMU_init.
> +	 * This allows udbg I/O to continue working after the MMU is
> +	 * turned on for real.
> +	 * It is safe to continue using the same virtual address as it is
> +	 * a reserved fixmap area.
> +	 */
> +	setbat(1, (unsigned long)early_debug_area,
> +	       ug_early_grab_io_addr(), 128*1024, PAGE_KERNEL_NCG);
> +}
> +
> +#endif /* CONFIG_PPC_EARLY_DEBUG_USBGECKO */
> +
> diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
> index 3929de3..bb6cde4 100644
> --- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
> +++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
> @@ -27,4 +27,6 @@ static inline void __init ug_udbg_init(void)
>  
>  #endif /* CONFIG_USBGECKO_UDBG */
>  
> +void __init udbg_init_usbgecko(void);
> +
>  #endif /* __USBGECKO_UDBG_H */

Patch

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 3b10051..11e385b 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -254,6 +254,14 @@  config PPC_EARLY_DEBUG_CPM
 	  using a CPM-based serial port.  This assumes that the bootwrapper
 	  has run, and set up the CPM in a particular way.
 
+config PPC_EARLY_DEBUG_USBGECKO
+	bool "Early debugging through the USB Gecko adapter"
+	depends on GAMECUBE_COMMON
+	select USBGECKO_UDBG
+	help
+	  Select this to enable early debugging for Nintendo GameCube/Wii
+	  consoles via an external USB Gecko adapter.
+
 endchoice
 
 config PPC_EARLY_DEBUG_44x_PHYSLOW
diff --git a/arch/powerpc/include/asm/udbg.h b/arch/powerpc/include/asm/udbg.h
index cd21e5e..11ae699 100644
--- a/arch/powerpc/include/asm/udbg.h
+++ b/arch/powerpc/include/asm/udbg.h
@@ -51,6 +51,7 @@  extern void __init udbg_init_btext(void);
 extern void __init udbg_init_44x_as1(void);
 extern void __init udbg_init_40x_realmode(void);
 extern void __init udbg_init_cpm(void);
+extern void __init udbg_init_usbgecko(void);
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_UDBG_H */
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 829c3fe..00b89c0 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -164,6 +164,9 @@  __after_mmu_off:
 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
 	bl	setup_cpm_bat
 #endif
+#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
+	bl	setup_usbgecko_bat
+#endif
 
 /*
  * Call setup_cpu for CPU 0 and initialize 6xx Idle
@@ -1203,6 +1206,28 @@  setup_cpm_bat:
 	blr
 #endif
 
+#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
+setup_usbgecko_bat:
+	/* prepare a BAT for early io */
+#if defined(CONFIG_GAMECUBE)
+	lis	r8, 0x0c00
+#elif defined(CONFIG_WII)
+	lis	r8, 0x0d00
+#else
+#error Invalid platform for USB Gecko based early debugging.
+#endif
+	/*
+	 * The virtual address used must match the virtual address
+	 * associated to the fixmap entry FIX_EARLY_DEBUG_BASE.
+	 */
+	lis	r11, 0xfffe	/* top 128K */
+	ori	r8, r8, 0x002a	/* uncached, guarded ,rw */
+	ori	r11, r11, 0x3	/* 128K */
+	mtspr	SPRN_DBAT1L, r8
+	mtspr	SPRN_DBAT1U, r11
+	blr
+#endif
+
 #ifdef CONFIG_8260
 /* Jump into the system reset for the rom.
  * We first disable the MMU, and then jump to the ROM reset address.
diff --git a/arch/powerpc/kernel/udbg.c b/arch/powerpc/kernel/udbg.c
index fc9af47..e39cad8 100644
--- a/arch/powerpc/kernel/udbg.c
+++ b/arch/powerpc/kernel/udbg.c
@@ -60,6 +60,8 @@  void __init udbg_early_init(void)
 	udbg_init_40x_realmode();
 #elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
 	udbg_init_cpm();
+#elif defined(CONFIG_PPC_EARLY_DEBUG_USBGECKO)
+	udbg_init_usbgecko();
 #endif
 
 #ifdef CONFIG_PPC_EARLY_DEBUG
diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
index ba4c7cc..edc956c 100644
--- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
+++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c
@@ -17,6 +17,7 @@ 
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/udbg.h>
+#include <asm/fixmap.h>
 
 #include "usbgecko_udbg.h"
 
@@ -270,3 +271,58 @@  done:
 		of_node_put(np);
 	return;
 }
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO
+
+static phys_addr_t __init ug_early_grab_io_addr(void)
+{
+#if defined(CONFIG_GAMECUBE)
+	return 0x0c000000;
+#elif defined(CONFIG_WII)
+	return 0x0d000000;
+#else
+#error Invalid platform for USB Gecko based early debugging.
+#endif
+}
+
+/*
+ * USB Gecko early debug support initialization for udbg.
+ */
+void __init udbg_init_usbgecko(void)
+{
+	void __iomem *early_debug_area;
+	void __iomem *exi_io_base;
+
+	/*
+	 * At this point we have a BAT already setup that enables I/O
+	 * to the EXI hardware.
+	 *
+	 * The BAT uses a virtual address range reserved at the fixmap.
+	 * This must match the virtual address configured in
+	 * head_32.S:setup_usbgecko_bat().
+	 */
+	early_debug_area = (void __iomem *)__fix_to_virt(FIX_EARLY_DEBUG_BASE);
+	exi_io_base = early_debug_area + 0x00006800;
+
+	/* try to detect a USB Gecko */
+	if (!ug_udbg_probe(exi_io_base))
+		return;
+
+	/* we found a USB Gecko, load udbg hooks */
+	udbg_putc = ug_udbg_putc;
+	udbg_getc = ug_udbg_getc;
+	udbg_getc_poll = ug_udbg_getc_poll;
+
+	/*
+	 * Prepare again the same BAT for MMU_init.
+	 * This allows udbg I/O to continue working after the MMU is
+	 * turned on for real.
+	 * It is safe to continue using the same virtual address as it is
+	 * a reserved fixmap area.
+	 */
+	setbat(1, (unsigned long)early_debug_area,
+	       ug_early_grab_io_addr(), 128*1024, PAGE_KERNEL_NCG);
+}
+
+#endif /* CONFIG_PPC_EARLY_DEBUG_USBGECKO */
+
diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
index 3929de3..bb6cde4 100644
--- a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
+++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.h
@@ -27,4 +27,6 @@  static inline void __init ug_udbg_init(void)
 
 #endif /* CONFIG_USBGECKO_UDBG */
 
+void __init udbg_init_usbgecko(void);
+
 #endif /* __USBGECKO_UDBG_H */