Pointer arguments for 32bit ARC PROMs must reside in CKSEG0/1. While the initial stack resides in CKSEG0 the first kernel thread stack is already placed at a XKPHYS address, which ARC32 can't handle. The workaround here is to use static variables, which are placed into BSS and linked to a CKSEG0 address.
Signed-off-by: Thomas Bogendoerfer <[email protected]> --- arch/mips/fw/arc/promlib.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/mips/fw/arc/promlib.c b/arch/mips/fw/arc/promlib.c index be381307fbb0..5e9e840a9314 100644 --- a/arch/mips/fw/arc/promlib.c +++ b/arch/mips/fw/arc/promlib.c @@ -11,6 +11,21 @@ #include <asm/bcache.h> #include <asm/setup.h> +#if defined(CONFIG_64BIT) && defined(CONFIG_FW_ARC32) +/* + * For 64bit kernels working with a 32bit ARC PROM pointer arguments + * for ARC calls need to reside in CKEG0/1. But as soon as the kernel + * switches to it's first kernel thread stack is set to an address in + * XKPHYS, so anything on stack can't be used anymore. This is solved + * by using a * static declartion variables are put into BSS, which is + * linked to a CKSEG0 address. Since this is only used on UP platforms + * there is not spinlock needed + */ +#define O32_STATIC static +#else +#define O32_STATIC +#endif + /* * IP22 boardcache is not compatible with board caches. Thus we disable it * during romvec action. Since r4xx0.c is always compiled and linked with your @@ -23,8 +38,10 @@ void prom_putchar(char c) { - ULONG cnt; - CHAR it = c; + O32_STATIC ULONG cnt; + O32_STATIC CHAR it; + + it = c; bc_disable(); ArcWrite(1, &it, 1, &cnt); @@ -33,8 +50,8 @@ void prom_putchar(char c) char prom_getchar(void) { - ULONG cnt; - CHAR c; + O32_STATIC ULONG cnt; + O32_STATIC CHAR c; bc_disable(); ArcRead(0, &c, 1, &cnt); -- 2.16.4
