1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1996 David S. Miller (dm@sgi.com) 7 * Compatibility with board caches, Ulf Carlsson 8 */ 9 #include <linux/kernel.h> 10 #include <asm/sgialib.h> 11 #include <asm/bcache.h> 12 #include <asm/setup.h> 13 14 #if defined(CONFIG_64BIT) && defined(CONFIG_FW_ARC32) 15 /* 16 * For 64bit kernels working with a 32bit ARC PROM pointer arguments 17 * for ARC calls need to reside in CKEG0/1. But as soon as the kernel 18 * switches to its first kernel thread stack is set to an address in 19 * XKPHYS, so anything on stack can't be used anymore. This is solved 20 * by using a * static declaration variables are put into BSS, which is 21 * linked to a CKSEG0 address. Since this is only used on UP platforms 22 * there is no spinlock needed 23 */ 24 #define O32_STATIC static 25 #else 26 #define O32_STATIC 27 #endif 28 29 /* 30 * IP22 boardcache is not compatible with board caches. Thus we disable it 31 * during romvec action. Since r4xx0.c is always compiled and linked with your 32 * kernel, this shouldn't cause any harm regardless what MIPS processor you 33 * have. 34 * 35 * The ARC write and read functions seem to interfere with the serial lines 36 * in some way. You should be careful with them. 37 */ 38 39 void prom_putchar(char c) 40 { 41 O32_STATIC ULONG cnt; 42 O32_STATIC CHAR it; 43 44 it = c; 45 46 bc_disable(); 47 ArcWrite(1, &it, 1, &cnt); 48 bc_enable(); 49 } 50 51 char prom_getchar(void) 52 { 53 O32_STATIC ULONG cnt; 54 O32_STATIC CHAR c; 55 56 bc_disable(); 57 ArcRead(0, &c, 1, &cnt); 58 bc_enable(); 59 60 return c; 61 } 62