u-boot/post/drivers/memory.c

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/*
* (C) Copyright 2002
* 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
*/
#include <common.h>
/* Memory test
*
* General observations:
* o The recommended test sequence is to test the data lines: if they are
* broken, nothing else will work properly. Then test the address
* lines. Finally, test the cells in the memory now that the test
* program knows that the address and data lines work properly.
* This sequence also helps isolate and identify what is faulty.
*
* o For the address line test, it is a good idea to use the base
* address of the lowest memory location, which causes a '1' bit to
* walk through a field of zeros on the address lines and the highest
* memory location, which causes a '0' bit to walk through a field of
* '1's on the address line.
*
* o Floating buses can fool memory tests if the test routine writes
* a value and then reads it back immediately. The problem is, the
* write will charge the residual capacitance on the data bus so the
* bus retains its state briefely. When the test program reads the
* value back immediately, the capacitance of the bus can allow it
* to read back what was written, even though the memory circuitry
* is broken. To avoid this, the test program should write a test
* pattern to the target location, write a different pattern elsewhere
* to charge the residual capacitance in a differnt manner, then read
* the target location back.
*
* o Always read the target location EXACTLY ONCE and save it in a local
* variable. The problem with reading the target location more than
* once is that the second and subsequent reads may work properly,
* resulting in a failed test that tells the poor technician that
* "Memory error at 00000000, wrote aaaaaaaa, read aaaaaaaa" which
* doesn't help him one bit and causes puzzled phone calls. Been there,
* done that.
*
* Data line test:
* ---------------
* This tests data lines for shorts and opens by forcing adjacent data
* to opposite states. Because the data lines could be routed in an
* arbitrary manner the must ensure test patterns ensure that every case
* is tested. By using the following series of binary patterns every
* combination of adjacent bits is test regardless of routing.
*
* ...101010101010101010101010
* ...110011001100110011001100
* ...111100001111000011110000
* ...111111110000000011111111
*
* Carrying this out, gives us six hex patterns as follows:
*
* 0xaaaaaaaaaaaaaaaa
* 0xcccccccccccccccc
* 0xf0f0f0f0f0f0f0f0
* 0xff00ff00ff00ff00
* 0xffff0000ffff0000
* 0xffffffff00000000
*
* To test for short and opens to other signals on our boards, we
* simply test with the 1's complemnt of the paterns as well, resulting
* in twelve patterns total.
*
* After writing a test pattern. a special pattern 0x0123456789ABCDEF is
* written to a different address in case the data lines are floating.
* Thus, if a byte lane fails, you will see part of the special
* pattern in that byte lane when the test runs. For example, if the
* xx__xxxxxxxxxxxx byte line fails, you will see aa23aaaaaaaaaaaa
* (for the 'a' test pattern).
*
* Address line test:
* ------------------
* This function performs a test to verify that all the address lines
* hooked up to the RAM work properly. If there is an address line
* fault, it usually shows up as two different locations in the address
* map (related by the faulty address line) mapping to one physical
* memory storage location. The artifact that shows up is writing to
* the first location "changes" the second location.
*
* To test all address lines, we start with the given base address and
* xor the address with a '1' bit to flip one address line. For each
* test, we shift the '1' bit left to test the next address line.
*
* In the actual code, we start with address sizeof(ulong) since our
* test pattern we use is a ulong and thus, if we tried to test lower
* order address bits, it wouldn't work because our pattern would
* overwrite itself.
*
* Example for a 4 bit address space with the base at 0000:
* 0000 <- base
* 0001 <- test 1
* 0010 <- test 2
* 0100 <- test 3
* 1000 <- test 4
* Example for a 4 bit address space with the base at 0010:
* 0010 <- base
* 0011 <- test 1
* 0000 <- (below the base address, skipped)
* 0110 <- test 2
* 1010 <- test 3
*
* The test locations are successively tested to make sure that they are
* not "mirrored" onto the base address due to a faulty address line.
* Note that the base and each test location are related by one address
* line flipped. Note that the base address need not be all zeros.
*
* Memory tests 1-4:
* -----------------
* These tests verify RAM using sequential writes and reads
* to/from RAM. There are several test cases that use different patterns to
* verify RAM. Each test case fills a region of RAM with one pattern and
* then reads the region back and compares its contents with the pattern.
* The following patterns are used:
*
* 1a) zero pattern (0x00000000)
* 1b) negative pattern (0xffffffff)
* 1c) checkerboard pattern (0x55555555)
* 1d) checkerboard pattern (0xaaaaaaaa)
* 2) bit-flip pattern ((1 << (offset % 32))
* 3) address pattern (offset)
* 4) address pattern (~offset)
*
* Being run in normal mode, the test verifies only small 4Kb
* regions of RAM around each 1Mb boundary. For example, for 64Mb
* RAM the following areas are verified: 0x00000000-0x00000800,
* 0x000ff800-0x00100800, 0x001ff800-0x00200800, ..., 0x03fff800-
* 0x04000000. If the test is run in slow-test mode, it verifies
* the whole RAM.
*/
#include <post.h>
#include <watchdog.h>
#if CONFIG_POST & CFG_POST_MEMORY
DECLARE_GLOBAL_DATA_PTR;
/*
* Define INJECT_*_ERRORS for testing error detection in the presence of
* _good_ hardware.
*/
#undef INJECT_DATA_ERRORS
#undef INJECT_ADDRESS_ERRORS
#ifdef INJECT_DATA_ERRORS
#warning "Injecting data line errors for testing purposes"
#endif
#ifdef INJECT_ADDRESS_ERRORS
#warning "Injecting address line errors for testing purposes"
#endif
/*
* This function performs a double word move from the data at
* the source pointer to the location at the destination pointer.
* This is helpful for testing memory on processors which have a 64 bit
* wide data bus.
*
* On those PowerPC with FPU, use assembly and a floating point move:
* this does a 64 bit move.
*
* For other processors, let the compiler generate the best code it can.
*/
static void move64(const unsigned long long *src, unsigned long long *dest)
{
#if defined(CONFIG_MPC8260) || defined(CONFIG_MPC824X)
asm ("lfd 0, 0(3)\n\t" /* fpr0 = *scr */
"stfd 0, 0(4)" /* *dest = fpr0 */
: : : "fr0" ); /* Clobbers fr0 */
return;
#else
*dest = *src;
#endif
}
/*
* This is 64 bit wide test patterns. Note that they reside in ROM
* (which presumably works) and the tests write them to RAM which may
* not work.
*
* The "otherpattern" is written to drive the data bus to values other
* than the test pattern. This is for detecting floating bus lines.
*
*/
const static unsigned long long pattern[] = {
0xaaaaaaaaaaaaaaaaULL,
0xccccccccccccccccULL,
0xf0f0f0f0f0f0f0f0ULL,
0xff00ff00ff00ff00ULL,
0xffff0000ffff0000ULL,
0xffffffff00000000ULL,
0x00000000ffffffffULL,
0x0000ffff0000ffffULL,
0x00ff00ff00ff00ffULL,
0x0f0f0f0f0f0f0f0fULL,
0x3333333333333333ULL,
0x5555555555555555ULL
};
const unsigned long long otherpattern = 0x0123456789abcdefULL;
static int memory_post_dataline(unsigned long long * pmem)
{
unsigned long long temp64 = 0;
int num_patterns = sizeof(pattern)/ sizeof(pattern[0]);
int i;
unsigned int hi, lo, pathi, patlo;
int ret = 0;
for ( i = 0; i < num_patterns; i++) {
move64(&(pattern[i]), pmem++);
/*
* Put a different pattern on the data lines: otherwise they
* may float long enough to read back what we wrote.
*/
move64(&otherpattern, pmem--);
move64(pmem, &temp64);
#ifdef INJECT_DATA_ERRORS
temp64 ^= 0x00008000;
#endif
if (temp64 != pattern[i]){
pathi = (pattern[i]>>32) & 0xffffffff;
patlo = pattern[i] & 0xffffffff;
hi = (temp64>>32) & 0xffffffff;
lo = temp64 & 0xffffffff;
post_log ("Memory (date line) error at %08x, "
"wrote %08x%08x, read %08x%08x !\n",
pmem, pathi, patlo, hi, lo);
ret = -1;
}
}
return ret;
}
static int memory_post_addrline(ulong *testaddr, ulong *base, ulong size)
{
ulong *target;
ulong *end;
ulong readback;
ulong xor;
int ret = 0;
end = (ulong *)((ulong)base + size); /* pointer arith! */
xor = 0;
for(xor = sizeof(ulong); xor > 0; xor <<= 1) {
target = (ulong *)((ulong)testaddr ^ xor);
if((target >= base) && (target < end)) {
*testaddr = ~*target;
readback = *target;
#ifdef INJECT_ADDRESS_ERRORS
if(xor == 0x00008000) {
readback = *testaddr;
}
#endif
if(readback == *testaddr) {
post_log ("Memory (address line) error at %08x<->%08x, "
"XOR value %08x !\n",
testaddr, target, xor);
ret = -1;
}
}
}
return ret;
}
static int memory_post_test1 (unsigned long start,
unsigned long size,
unsigned long val)
{
unsigned long i;
ulong *mem = (ulong *) start;
ulong readback;
int ret = 0;
for (i = 0; i < size / sizeof (ulong); i++) {
mem[i] = val;
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
for (i = 0; i < size / sizeof (ulong) && ret == 0; i++) {
readback = mem[i];
if (readback != val) {
post_log ("Memory error at %08x, "
"wrote %08x, read %08x !\n",
mem + i, val, readback);
ret = -1;
break;
}
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
return ret;
}
static int memory_post_test2 (unsigned long start, unsigned long size)
{
unsigned long i;
ulong *mem = (ulong *) start;
ulong readback;
int ret = 0;
for (i = 0; i < size / sizeof (ulong); i++) {
mem[i] = 1 << (i % 32);
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
for (i = 0; i < size / sizeof (ulong) && ret == 0; i++) {
readback = mem[i];
if (readback != (1 << (i % 32))) {
post_log ("Memory error at %08x, "
"wrote %08x, read %08x !\n",
mem + i, 1 << (i % 32), readback);
ret = -1;
break;
}
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
return ret;
}
static int memory_post_test3 (unsigned long start, unsigned long size)
{
unsigned long i;
ulong *mem = (ulong *) start;
ulong readback;
int ret = 0;
for (i = 0; i < size / sizeof (ulong); i++) {
mem[i] = i;
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
for (i = 0; i < size / sizeof (ulong) && ret == 0; i++) {
readback = mem[i];
if (readback != i) {
post_log ("Memory error at %08x, "
"wrote %08x, read %08x !\n",
mem + i, i, readback);
ret = -1;
break;
}
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
return ret;
}
static int memory_post_test4 (unsigned long start, unsigned long size)
{
unsigned long i;
ulong *mem = (ulong *) start;
ulong readback;
int ret = 0;
for (i = 0; i < size / sizeof (ulong); i++) {
mem[i] = ~i;
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
for (i = 0; i < size / sizeof (ulong) && ret == 0; i++) {
readback = mem[i];
if (readback != ~i) {
post_log ("Memory error at %08x, "
"wrote %08x, read %08x !\n",
mem + i, ~i, readback);
ret = -1;
break;
}
if (i % 1024 == 0)
WATCHDOG_RESET ();
}
return ret;
}
static int memory_post_tests (unsigned long start, unsigned long size)
{
int ret = 0;
if (ret == 0)
ret = memory_post_dataline ((unsigned long long *)start);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_addrline ((ulong *)start, (ulong *)start, size);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_addrline ((ulong *)(start + size - 8),
(ulong *)start, size);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test1 (start, size, 0x00000000);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test1 (start, size, 0xffffffff);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test1 (start, size, 0x55555555);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test1 (start, size, 0xaaaaaaaa);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test2 (start, size);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test3 (start, size);
WATCHDOG_RESET ();
if (ret == 0)
ret = memory_post_test4 (start, size);
WATCHDOG_RESET ();
return ret;
}
int memory_post_test (int flags)
{
int ret = 0;
bd_t *bd = gd->bd;
unsigned long memsize = (bd->bi_memsize >= 256 << 20 ?
256 << 20 : bd->bi_memsize) - (1 << 20);
/* Limit area to be tested with the board info struct */
if (CFG_SDRAM_BASE + memsize > (ulong)bd)
memsize = (ulong)bd - CFG_SDRAM_BASE;
if (flags & POST_SLOWTEST) {
ret = memory_post_tests (CFG_SDRAM_BASE, memsize);
} else { /* POST_NORMAL */
unsigned long i;
for (i = 0; i < (memsize >> 20) && ret == 0; i++) {
if (ret == 0)
ret = memory_post_tests (i << 20, 0x800);
if (ret == 0)
ret = memory_post_tests ((i << 20) + 0xff800, 0x800);
}
}
return ret;
}
#endif /* CONFIG_POST & CFG_POST_MEMORY */