/* * (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. */ #ifdef CONFIG_POST #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(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((unsigned long long *)&(pattern[i]), pmem++); /* * Put a different pattern on the data lines: otherwise they * may float long enough to read back what we wrote. */ move64((unsigned long long *)&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); 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 */ #endif /* CONFIG_POST */