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: Pawel Moll <pawel.moll@arm.com>
This commit is contained in:
Pawel Moll 2012-07-11 17:07:25 +01:00
parent 375faa93cb
commit 1b820eaf42
3 changed files with 81 additions and 0 deletions

View file

@ -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

View file

@ -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

View file

@ -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();
}