diff --git a/flash.h b/flash.h
index 4bbd9a7..8e0ad7f 100644
--- a/flash.h
+++ b/flash.h
@@ -225,6 +225,7 @@
 #define TEST_OK_WRITE	(1 << 3)
 #define TEST_OK_PR	(TEST_OK_PROBE | TEST_OK_READ)
 #define TEST_OK_PRE	(TEST_OK_PROBE | TEST_OK_READ | TEST_OK_ERASE)
+#define TEST_OK_PRW	(TEST_OK_PROBE | TEST_OK_READ | TEST_OK_WRITE)
 #define TEST_OK_PREW	(TEST_OK_PROBE | TEST_OK_READ | TEST_OK_ERASE | TEST_OK_WRITE)
 #define TEST_OK_MASK	0x0f
 
@@ -596,8 +597,8 @@
 int probe_jedec(struct flashchip *flash);
 int erase_chip_jedec(struct flashchip *flash);
 int write_jedec(struct flashchip *flash, uint8_t *buf);
-int erase_sector_jedec(struct flashchip *flash, unsigned int page, int pagesize);
-int erase_block_jedec(struct flashchip *flash, unsigned int page, int blocksize);
+int erase_sector_jedec(struct flashchip *flash, unsigned int page, unsigned int pagesize);
+int erase_block_jedec(struct flashchip *flash, unsigned int page, unsigned int blocksize);
 int write_sector_jedec(chipaddr bios, uint8_t *src,
 		       chipaddr dst, unsigned int page_size);
 
@@ -657,6 +658,7 @@
 /* sst_fwhub.c */
 int probe_sst_fwhub(struct flashchip *flash);
 int erase_sst_fwhub(struct flashchip *flash);
+int erase_sst_fwhub_block(struct flashchip *flash, unsigned int offset, unsigned int page_size);
 int write_sst_fwhub(struct flashchip *flash, uint8_t *buf);
 
 /* w39v040c.c */
diff --git a/flashchips.c b/flashchips.c
index 83f6e96..1292d3e 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -2141,6 +2141,9 @@
 	},
 
 	{
+		/* Contrary to the data sheet, TBL# on the SST49LF004B affects the top 128kB (instead of 64kB)
+		 * and is only honored for 64k block erase, but not 4k sector erase.
+		 */
 		.vendor		= "SST",
 		.name		= "SST49LF004A/B",
 		.bustype	= CHIP_BUSTYPE_FWH, /* A/A Mux */
@@ -2151,7 +2154,20 @@
 		.tested		= TEST_OK_PREW,
 		.probe		= probe_sst_fwhub,
 		.probe_timing	= 1,		/* 150 ns | routine is wrapper to probe_jedec (sst_fwhub.c) */
-		.erase		= erase_sst_fwhub,
+		.erase		= NULL,
+		.block_erasers	=
+		{
+			{
+				.eraseblocks = { {4 * 1024, 128} },
+				.block_erase = erase_sector_jedec, /* missing unlock */
+			}, {
+				.eraseblocks = { {64 * 1024, 8} },
+				.block_erase = erase_sst_fwhub_block, /* same as erase_sector_block, but with unlock */
+			}, {
+				.eraseblocks = { {512 * 1024, 1} },
+				.block_erase = NULL, /* AA 55 80 AA 55 10, only in PP mode */
+			},
+		},
 		.write		= write_sst_fwhub,
 		.read		= read_memmapped,
 	},
diff --git a/jedec.c b/jedec.c
index d51f122..7029e98 100644
--- a/jedec.c
+++ b/jedec.c
@@ -175,7 +175,7 @@
 	return 0;
 }
 
-int erase_sector_jedec(struct flashchip *flash, unsigned int page, int pagesize)
+int erase_sector_jedec(struct flashchip *flash, unsigned int page, unsigned int pagesize)
 {
 	chipaddr bios = flash->virtual_memory;
 
@@ -204,7 +204,7 @@
 	return 0;
 }
 
-int erase_block_jedec(struct flashchip *flash, unsigned int block, int blocksize)
+int erase_block_jedec(struct flashchip *flash, unsigned int block, unsigned int blocksize)
 {
 	chipaddr bios = flash->virtual_memory;
 
diff --git a/sst_fwhub.c b/sst_fwhub.c
index e7ae9e9..ed45407 100644
--- a/sst_fwhub.c
+++ b/sst_fwhub.c
@@ -94,7 +94,7 @@
 	return 1;
 }
 
-int erase_sst_fwhub_block(struct flashchip *flash, int offset, int page_size)
+int erase_sst_fwhub_block(struct flashchip *flash, unsigned int offset, unsigned int page_size)
 {
 	uint8_t blockstatus = clear_sst_fwhub_block_lock(flash, offset);