diff options
Diffstat (limited to 'common')
| -rw-r--r-- | common/Makefile | 2 | ||||
| -rw-r--r-- | common/memsize.c | 77 |
2 files changed, 78 insertions, 1 deletions
diff --git a/common/Makefile b/common/Makefile index 5595c23..eaf2cac 100644 --- a/common/Makefile +++ b/common/Makefile @@ -47,7 +47,7 @@ COBJS = main.o ACEX1K.o altera.o bedbug.o \ hush.o kgdb.o lists.o lynxkdi.o miiphybb.o miiphyutil.o \ s_record.o soft_i2c.o soft_spi.o spartan2.o \ usb.o usb_kbd.o usb_storage.o \ - virtex2.o xilinx.o + virtex2.o xilinx.o memsize.o OBJS = $(AOBJS) $(COBJS) diff --git a/common/memsize.c b/common/memsize.c new file mode 100644 index 0000000..dbc812d --- /dev/null +++ b/common/memsize.c @@ -0,0 +1,77 @@ +/* + * (C) Copyright 2004 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + + +/* + * Check memory range for valid RAM. A simple memory test determines + * the actually available RAM size between addresses `base' and + * `base + maxsize'. + */ +long get_ram_size(volatile long *base, long maxsize) +{ + volatile long *addr; + long save[32]; + long cnt; + long val; + long size; + int i = 0; + + for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) { + addr = base + cnt; /* pointer arith! */ + save[i++] = *addr; + *addr = ~cnt; + } + + addr = base; + save[i] = *addr; + *addr = 0; + + if ((val = *addr) != 0) { + /* Restore the original data before leaving the function. + */ + *addr = save[i]; + for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) { + addr = base + cnt; + *addr = save[--i]; + } + return (0); + } + + for (cnt = 1; cnt < maxsize / sizeof (long); cnt <<= 1) { + addr = base + cnt; /* pointer arith! */ + val = *addr; + *addr = save[--i]; + if (val != ~cnt) { + size = cnt * sizeof (long); + /* Restore the original data before leaving the function. + */ + for (cnt <<= 1; cnt < maxsize / sizeof (long); cnt <<= 1) { + addr = base + cnt; + *addr = save[--i]; + } + return (size); + } + } + + return (maxsize); +} |