diff --git a/flashchips.c b/flashchips.c
index ce03379..bce9435 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -1506,7 +1506,7 @@
 		.model_id	= AMIC_A49LF040A,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_jedec,
 		.probe_timing	= TIMING_ZERO,	/* routine is wrapper to probe_jedec (pm49fl00x.c) */
@@ -1524,7 +1524,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -3422,7 +3422,6 @@
 		.model_id	= ATMEL_AT49LH002,
 		.total_size	= 256,
 		.page_size	= 0, /* unused */
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_ZERO,
@@ -3448,7 +3447,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -3460,7 +3459,6 @@
 		.model_id	= ATMEL_AT49LH004,
 		.total_size	= 512,
 		.page_size	= 0, /* unused */
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_ZERO,
@@ -3486,7 +3484,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -3498,7 +3496,6 @@
 		.model_id	= ATMEL_AT49LH00B4,
 		.total_size	= 512,
 		.page_size	= 0, /* unused */
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_ZERO,
@@ -3524,7 +3521,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -8458,7 +8455,6 @@
 		.model_id	= INTEL_82802AB,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine does not use probe_timing (82802ab.c) */
@@ -8473,7 +8469,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -8485,7 +8481,6 @@
 		.model_id	= INTEL_82802AC,
 		.total_size	= 1024,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine does not use probe_timing (82802ab.c) */
@@ -8500,7 +8495,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -13485,7 +13480,7 @@
 		.model_id	= PMC_PM49FL002,
 		.total_size	= 256,
 		.page_size	= 16 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_jedec,
 		.probe_timing	= TIMING_ZERO,	/* routine is wrapper to probe_jedec (pm49fl00x.c) */
@@ -13506,7 +13501,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -13518,7 +13513,7 @@
 		.model_id	= PMC_PM49FL004,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= TIMING_ZERO,
@@ -13539,7 +13534,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -14930,7 +14925,7 @@
 		.model_id	= SST_SST49LF002A,
 		.total_size	= 256,
 		.page_size	= 16 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 1,		/* 150 ns */
@@ -14952,7 +14947,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -14964,7 +14959,7 @@
 		.model_id	= SST_SST49LF003A,
 		.total_size	= 384,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 1,		/* 150 ns */
@@ -14986,7 +14981,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15001,7 +14996,7 @@
 		.model_id	= SST_SST49LF004A,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 1,		/* 150 ns */
@@ -15023,7 +15018,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15035,7 +15030,6 @@
 		.model_id	= SST_SST49LF004C,
 		.total_size	= 512,
 		.page_size	= 4 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (sst49lfxxxc.c) */
@@ -15059,7 +15053,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15071,7 +15065,7 @@
 		.model_id	= SST_SST49LF008A,
 		.total_size	= 1024,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 1,		/* 150 ns */
@@ -15093,7 +15087,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15105,7 +15099,6 @@
 		.model_id	= SST_SST49LF008C,
 		.total_size	= 1024,
 		.page_size	= 4 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (sst49lfxxxc.c) */
@@ -15129,7 +15122,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15141,7 +15134,6 @@
 		.model_id	= SST_SST49LF016C,
 		.total_size	= 2048,
 		.page_size	= 4 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (sst49lfxxxc.c) */
@@ -15165,7 +15157,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15273,7 +15265,7 @@
 		.model_id	= SST_SST49LF040B,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_EITHER_RESET | FEATURE_REGISTERMAP,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 1,		/* 150ns */
@@ -15294,7 +15286,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15338,7 +15330,6 @@
 		.model_id	= SST_SST49LF160C,
 		.total_size	= 2048,
 		.page_size	= 4 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (sst49lfxxxc.c) */
@@ -15362,7 +15353,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15625,7 +15616,6 @@
 		.model_id	= ST_M50FLW040A,
 		.total_size	= 512,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_FIXME,
@@ -15648,7 +15638,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15660,7 +15650,6 @@
 		.model_id	= ST_M50FLW040B,
 		.total_size	= 512,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_FIXME,
@@ -15683,7 +15672,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15695,7 +15684,6 @@
 		.model_id	= ST_M50FLW080A,
 		.total_size	= 1024,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_FIXME,
@@ -15719,7 +15707,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15731,7 +15719,6 @@
 		.model_id	= ST_M50FLW080B,
 		.total_size	= 1024,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_FIXME,
@@ -15755,7 +15742,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15767,7 +15754,6 @@
 		.model_id	= ST_M50FW002,
 		.total_size	= 256,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (82802ab.c) */
@@ -15791,7 +15777,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15803,7 +15789,6 @@
 		.model_id	= ST_M50FW016,
 		.total_size	= 2048,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (82802ab.c) */
@@ -15818,7 +15803,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15830,7 +15815,6 @@
 		.model_id	= ST_M50FW040,
 		.total_size	= 512,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (82802ab.c) */
@@ -15845,7 +15829,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15857,7 +15841,6 @@
 		.model_id	= ST_M50FW080,
 		.total_size	= 1024,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_OK_PR,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_IGNORED, /* routine doesn't use probe_timing (82802ab.c) */
@@ -15872,7 +15855,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15884,7 +15867,6 @@
 		.model_id	= ST_M50LPW080,
 		.total_size	= 1024,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_ZERO,	/* Datasheet has no timing info specified */
@@ -15899,7 +15881,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -15911,7 +15893,6 @@
 		.model_id	= ST_M50LPW116,
 		.total_size	= 2048,
 		.page_size	= 0,
-		.feature_bits	= FEATURE_REGISTERMAP,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_ZERO,	/* Datasheet has no timing info specified */
@@ -15933,7 +15914,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program & erase */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -16403,7 +16384,7 @@
 		.model_id	= SHARP_LHF00L04,
 		.total_size	= 1024,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_EITHER_RESET | FEATURE_REGISTERMAP,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_82802ab,
 		.probe_timing	= TIMING_ZERO,
@@ -16426,7 +16407,7 @@
 		.write		= write_82802ab,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -20017,7 +19998,7 @@
 		.model_id	= WINBOND_W39V040FA,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 10,
@@ -20039,7 +20020,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600},
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -20051,7 +20032,7 @@
 		.model_id	= WINBOND_W39V040B,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 10,
@@ -20070,7 +20051,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -20082,7 +20063,7 @@
 		.model_id	= WINBOND_W39V040C,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 10,
@@ -20100,7 +20081,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -20142,7 +20123,7 @@
 		.model_id	= WINBOND_W39V080FA,
 		.total_size	= 1024,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_jedec,
 		.probe_timing	= 10,
@@ -20161,7 +20142,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
@@ -20173,7 +20154,7 @@
 		.model_id	= WINBOND_W39V080FA_DM,
 		.total_size	= 512,
 		.page_size	= 64 * 1024,
-		.feature_bits	= FEATURE_REGISTERMAP | FEATURE_EITHER_RESET,
+		.feature_bits	= FEATURE_EITHER_RESET,
 		.tested		= TEST_UNTESTED,
 		.probe		= probe_jedec,
 		.probe_timing	= 10,
@@ -20191,7 +20172,7 @@
 		.write		= write_jedec_1,
 		.read		= read_memmapped,
 		.voltage	= {3000, 3600}, /* Also has 12V fast program */
-		.prepare_access	= prepare_memory_access,
+		.prepare_access	= prepare_memory_register_access,
 		.finish_access	= finish_memory_access,
 	},
 
diff --git a/include/chipdrivers.h b/include/chipdrivers.h
index 10090d8..8e22c1d 100644
--- a/include/chipdrivers.h
+++ b/include/chipdrivers.h
@@ -217,6 +217,7 @@
 
 /* memory_bus.c */
 int prepare_memory_access(struct flashctx *, enum preparation_steps);
+int prepare_memory_register_access(struct flashctx *, enum preparation_steps);
 void finish_memory_access(struct flashctx *);
 
 #endif /* !__CHIPDRIVERS_H__ */
diff --git a/include/flash.h b/include/flash.h
index fad5750..561a597 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -108,7 +108,6 @@
 #define MAX_CHIP_RESTORE_FUNCTIONS 4
 
 /* Feature bits used for non-SPI only */
-#define FEATURE_REGISTERMAP	(1 << 0)
 #define FEATURE_LONG_RESET	(0 << 4)
 #define FEATURE_SHORT_RESET	(1 << 4)
 #define FEATURE_EITHER_RESET	FEATURE_LONG_RESET
diff --git a/memory_bus.c b/memory_bus.c
index 304766d..9c57d3b 100644
--- a/memory_bus.c
+++ b/memory_bus.c
@@ -57,8 +57,8 @@
 		return 0;
 
 	const chipsize_t size = flash->chip->total_size * 1024;
-	uintptr_t base = flashbase ? flashbase : (0xffffffff - size + 1);
-	void *addr = programmer_map_flash_region(flash, flash->chip->name, base, size);
+	const uintptr_t base = flashbase ? flashbase : (0xffffffff - size + 1);
+	void *const addr = programmer_map_flash_region(flash, flash->chip->name, base, size);
 	if (addr == ERROR_PTR) {
 		msg_perr("Could not map flash chip %s at 0x%0*" PRIxPTR ".\n",
 			 flash->chip->name, PRIxPTR_WIDTH, base);
@@ -67,22 +67,30 @@
 	flash->physical_memory = base;
 	flash->virtual_memory = (chipaddr)addr;
 
+	return 0;
+}
+
+int prepare_memory_register_access(struct flashctx *flash, enum preparation_steps prep)
+{
+	if (prepare_memory_access(flash, prep))
+		return 1;
+
 	/*
 	 * FIXME: Special function registers normally live 4 MByte below flash space,
 	 * but it might be somewhere completely different on some chips and programmers,
 	 * or not mappable at all. Ignore these problems for now and always report success.
 	 */
-	if (flash->chip->feature_bits & FEATURE_REGISTERMAP) {
-		base = 0xffffffff - size - 0x400000 + 1;
-		addr = programmer_map_flash_region(flash, "flash chip registers", base, size);
-		if (addr == ERROR_PTR) {
-			msg_pdbg2("Could not map flash chip registers %s at 0x%0*" PRIxPTR ".\n",
-				 flash->chip->name, PRIxPTR_WIDTH, base);
-			return 0;
-		}
-		flash->physical_registers = base;
-		flash->virtual_registers = (chipaddr)addr;
+	const chipsize_t size = flash->chip->total_size * 1024;
+	const uintptr_t base = 0xffffffff - size - 0x400000 + 1;
+	void *const addr = programmer_map_flash_region(flash, "flash chip registers", base, size);
+	if (addr == ERROR_PTR) {
+		msg_pdbg2("Could not map flash chip registers %s at 0x%0*" PRIxPTR ".\n",
+			 flash->chip->name, PRIxPTR_WIDTH, base);
+		return 0;
 	}
+	flash->physical_registers = base;
+	flash->virtual_registers = (chipaddr)addr;
+
 	return 0;
 }