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Commit 1b820eaf authored by Pawel Moll's avatar Pawel Moll
Browse files

ARM: vexpress: Config option for early printk console 



Versatile Express platform can be used in different configurations,
the console UART used by early printk may be located at different
addresses in the address space.

This patch makes it possible to select the base address of a PL011
UART to be used as a console output in the kernel configuration.
The default behaviour is still the heuristic detecting memory map
on Cortex-A core tiles.

The zImage decompressor will use the same configuration values
or print out nothing if DEBUG_LL is not enabled.

Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
parent 375faa93

arch/arm/Kconfig.debug

+26 −0
Original line number Diff line number Diff line
@@ -310,6 +310,32 @@ choice 
		  The uncompressor code port configuration is now handled

		  by CONFIG_S3C_LOWLEVEL_UART_PORT.



	config DEBUG_VEXPRESS_UART0_DETECT

		bool "Autodetect UART0 on Versatile Express Cortex-A core tiles"

		depends on ARCH_VEXPRESS && CPU_CP15_MMU

		help

		  This option enables a simple heuristic which tries to determine

		  the motherboard's memory map variant (original or RS1) and then

		  choose the relevant UART0 base address.



		  Note that this will only work with standard A-class core tiles,

		  and may fail with non-standard SMM or custom software models.



	config DEBUG_VEXPRESS_UART0_CA9

		bool "Use PL011 UART0 at 0x10009000 (V2P-CA9 core tile)"

		depends on ARCH_VEXPRESS

		help

		  This option selects UART0 at 0x10009000. Except for custom models,

		  this applies only to the V2P-CA9 tile.



	config DEBUG_VEXPRESS_UART0_RS1

		bool "Use PL011 UART0 at 0x1c090000 (RS1 complaint tiles)"

		depends on ARCH_VEXPRESS

		help

		  This option selects UART0 at 0x1c090000. This applies to most

		  of the tiles using the RS1 memory map, including all new A-class

		  core tiles, FPGA-based SMMs and software models.



	config DEBUG_LL_UART_NONE

		bool "No low-level debugging UART"

		help

arch/arm/mach-vexpress/include/mach/debug-macro.S

+41 −0
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ 


#define DEBUG_LL_VIRT_BASE		0xf8000000



#if defined(CONFIG_DEBUG_VEXPRESS_UART0_DETECT)



		.macro	addruart,rp,rv,tmp



		@ Make an educated guess regarding the memory map:
@@ -41,3 +43,42 @@ 
		.endm



#include <asm/hardware/debug-pl01x.S>



#elif defined(CONFIG_DEBUG_VEXPRESS_UART0_CA9)



		.macro	addruart,rp,rv,tmp

		mov	\rp, #DEBUG_LL_UART_OFFSET

		orr	\rv, \rp, #DEBUG_LL_VIRT_BASE

		orr	\rp, \rp, #DEBUG_LL_PHYS_BASE

		.endm



#include <asm/hardware/debug-pl01x.S>



#elif defined(CONFIG_DEBUG_VEXPRESS_UART0_RS1)



		.macro	addruart,rp,rv,tmp

		mov	\rp, #DEBUG_LL_UART_OFFSET_RS1

		orr	\rv, \rp, #DEBUG_LL_VIRT_BASE

		orr	\rp, \rp, #DEBUG_LL_PHYS_BASE_RS1

		.endm



#include <asm/hardware/debug-pl01x.S>



#else /* CONFIG_DEBUG_LL_UART_NONE */



		.macro	addruart, rp, rv, tmp

		/* Safe dummy values */

		mov	\rp, #0

		mov	\rv, #DEBUG_LL_VIRT_BASE

		.endm



		.macro	senduart,rd,rx

		.endm



		.macro	waituart,rd,rx

		.endm



		.macro	busyuart,rd,rx

		.endm



#endif

arch/arm/mach-vexpress/include/mach/uncompress.h

+14 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 


static unsigned long get_uart_base(void)

{

#if defined(CONFIG_DEBUG_VEXPRESS_UART0_DETECT)

	unsigned long mpcore_periph;



	/*
@@ -42,6 +43,13 @@ static unsigned long get_uart_base(void) 
		return UART_BASE;

	else

		return UART_BASE_RS1;

#elif defined(CONFIG_DEBUG_VEXPRESS_UART0_CA9)

	return UART_BASE;

#elif defined(CONFIG_DEBUG_VEXPRESS_UART0_RS1)

	return UART_BASE_RS1;

#else

	return 0;

#endif

}



/*
@@ -51,6 +59,9 @@ static inline void putc(int c) 
{

	unsigned long base = get_uart_base();



	if (!base)

		return;



	while (AMBA_UART_FR(base) & (1 << 5))

		barrier();
@@ -61,6 +72,9 @@ static inline void flush(void) 
{

	unsigned long base = get_uart_base();



	if (!base)

		return;



	while (AMBA_UART_FR(base) & (1 << 3))

		barrier();

}