diff options
| author | Eric Norum <WENorum@lbl.gov> | 2009-06-02 21:13:23 +0000 |
|---|---|---|
| committer | Eric Norum <WENorum@lbl.gov> | 2009-06-02 21:13:23 +0000 |
| commit | 7920d156e0e4ab0cda3920b2b1cdf130233ebb1a (patch) | |
| tree | c5fea0664c758a734fcfd92432201f5d16543f07 /c | |
| parent | 2009-05-28 Joel Sherrill <joel.sherrill@OARcorp.com> (diff) | |
| download | rtems-7920d156e0e4ab0cda3920b2b1cdf130233ebb1a.tar.bz2 | |
As per Freescale chip errata, disable buffered writes.
Diffstat (limited to 'c')
| -rw-r--r-- | c/src/lib/libbsp/m68k/uC5282/ChangeLog | 4 | ||||
| -rw-r--r-- | c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c | 18 |
2 files changed, 19 insertions, 3 deletions
diff --git a/c/src/lib/libbsp/m68k/uC5282/ChangeLog b/c/src/lib/libbsp/m68k/uC5282/ChangeLog index c6fd4f78af..acfbd793cf 100644 --- a/c/src/lib/libbsp/m68k/uC5282/ChangeLog +++ b/c/src/lib/libbsp/m68k/uC5282/ChangeLog @@ -1,3 +1,7 @@ +2009-06-02 Eric Norum <norume@aps.anl.gov> + + * startup/bspstart.c: Turn off buffered writes. + 2009-03-02 Till Straumann <strauman@slac.stanford.edu> PR 1375/bsps diff --git a/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c b/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c index ebbda06d6e..260db55f3f 100644 --- a/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c +++ b/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c @@ -57,6 +57,20 @@ * should be followed immediately by a NOP instruction. This avoids the cache * corruption problem. * DATECODES AFFECTED: All + * + * + * Buffered writes must be disabled as described in "MCF5282 Chip Errata", + * MCF5282DE, Rev. 6, 5/2009: + * SECF124: Buffered Write May Be Executed Twice + * Errata type: Silicon + * Affected component: Cache + * Description: If buffered writes are enabled using the CACR or ACR + * registers, the imprecise write transaction generated + * by a buffered write may be executed twice. + * Workaround: Do not enable buffered writes in the CACR or ACR registers: + * CACR[8] = DBWE (default buffered write enable) must be 0 + * ACRn[5] = BUFW (buffered write enable) must be 0 + * Fix plan: Currently, there are no plans to fix this. */ #define m68k_set_cacr_nop(_cacr) asm volatile ("movec %0,%%cacr\n\tnop" : : "d" (_cacr)) #define m68k_set_cacr(_cacr) asm volatile ("movec %0,%%cacr" : : "d" (_cacr)) @@ -67,7 +81,7 @@ * Read/write copy of cache registers * Split instruction/data or instruction-only * Allow CPUSHL to invalidate a cache line - * Enable buffered writes + * Disable buffered writes * No burst transfers on non-cacheable accesses * Default cache mode is *disabled* (cache only ACRx areas) */ @@ -75,7 +89,6 @@ uint32_t mcf5282_cacr_mode = MCF5XXX_CACR_CENB | #ifndef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE MCF5XXX_CACR_DISD | #endif - MCF5XXX_CACR_DBWE | MCF5XXX_CACR_DCM; uint32_t mcf5282_acr0_mode = 0; uint32_t mcf5282_acr1_mode = 0; @@ -269,7 +282,6 @@ void bsp_start( void ) mcf5282_acr0_mode = MCF5XXX_ACR_AB((uint32_t)_RamBase) | MCF5XXX_ACR_AM((uint32_t)_RamSize-1) | MCF5XXX_ACR_EN | - MCF5XXX_ACR_BWE | MCF5XXX_ACR_SM_IGNORE; m68k_set_acr0(mcf5282_acr0_mode); |