WSL2-Linux-Kernel/arch/mips/fw/arc/promlib.c

62 строки
1.6 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996 David S. Miller (dm@sgi.com)
* Compatibility with board caches, Ulf Carlsson
*/
#include <linux/kernel.h>
#include <asm/sgialib.h>
#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
* kernel, this shouldn't cause any harm regardless what MIPS processor you
* have.
*
* The ARC write and read functions seem to interfere with the serial lines
* in some way. You should be careful with them.
*/
void prom_putchar(char c)
{
O32_STATIC ULONG cnt;
O32_STATIC CHAR it;
it = c;
bc_disable();
ArcWrite(1, &it, 1, &cnt);
bc_enable();
}
char prom_getchar(void)
{
O32_STATIC ULONG cnt;
O32_STATIC CHAR c;
bc_disable();
ArcRead(0, &c, 1, &cnt);
bc_enable();
return c;
}