diff --git a/chips/v851_v853.c b/chips/v851_v853.c
index 5b43324..4072ee9 100644
--- a/chips/v851_v853.c
+++ b/chips/v851_v853.c
@@ -1614,13 +1614,67 @@ static int chip_spi_run(struct xfel_ctx_t * ctx, uint8_t * cbuf, uint32_t clen)
 	return 1;
 }
 
+enum {
+	SID_PRCTL		= 0x03006000 + 0x040,
+	SID_PRKEY		= 0x03006000 + 0x050,
+	SID_RDKEY 		= 0x03006000 + 0x060,
+	EFUSE_HV_SWITCH	= 0x07090000 + 0x204,
+};
+
+static uint32_t efuse_read(struct xfel_ctx_t * ctx, uint32_t offset)
+{
+	uint32_t val;
+
+	val = payload_read32(ctx, SID_PRCTL);
+	val &= ~((0x1ff << 16) | 0x3);
+	val |= offset << 16;
+	payload_write32(ctx, SID_PRCTL, val);
+	val &= ~((0xff << 8) | 0x3);
+	val |= (0xac << 8) | 0x2;
+	payload_write32(ctx, SID_PRCTL, val);
+	while(payload_read32(ctx, SID_PRCTL) & 0x2);
+	val &= ~((0x1ff << 16) | (0xff << 8) | 0x3);
+	payload_write32(ctx, SID_PRCTL, val);
+	val = payload_read32(ctx, SID_RDKEY);
+
+	return val;
+}
+
+static void efuse_write(struct xfel_ctx_t * ctx, uint32_t offset, uint32_t value)
+{
+	uint32_t val;
+
+	payload_write32(ctx, EFUSE_HV_SWITCH, 0x1);
+	payload_write32(ctx, SID_PRKEY, value);
+	val = payload_read32(ctx, SID_PRCTL);
+	val &= ~((0x1ff << 16) | 0x3);
+	val |= offset << 16;
+	payload_write32(ctx, SID_PRCTL, val);
+	val &= ~((0xff << 8) | 0x3);
+	val |= (0xac << 8) | 0x1;
+	payload_write32(ctx, SID_PRCTL, val);
+	while(payload_read32(ctx, SID_PRCTL) & 0x1);
+	val &= ~((0x1ff << 16) | (0xff << 8) | 0x3);
+	payload_write32(ctx, SID_PRCTL, val);
+	payload_write32(ctx, EFUSE_HV_SWITCH, 0x0);
+}
+
 static const struct sid_section_t {
 	char * name;
 	uint32_t offset;
 	uint32_t size_bits;
 } sids[] = {
-	{ "chipid",  0x0000,  128 },
-	{ "unknown", 0x0010, 1920 },
+	{ "chipid",         0x0000,  128 },
+	{ "brom-conf-try",  0x0010,   32 },
+	{ "thermal-sensor", 0x0014,   64 },
+	{ "ft-zone",        0x001c,  128 },
+	{ "reserved1",      0x002c,   96 },
+	{ "write-protect",  0x0038,   32 },
+	{ "read-protect",   0x003c,   32 },
+	{ "lcjs",           0x0040,   32 },
+	{ "reserved2",      0x0044,  800 },
+	{ "rotpk",          0x00a8,  256 },
+	{ "reserved3",      0x00c8,  448 },
 };
 
 static int chip_extra(struct xfel_ctx_t * ctx, int argc, char * argv[])
@@ -1640,7 +1694,7 @@ static int chip_extra(struct xfel_ctx_t * ctx, int argc, char * argv[])
 					{
 						uint32_t count = sids[n].size_bits / 32;
 						for(int i = 0; i < count; i++)
-							buffer[i] = payload_read32(ctx, 0x03006200 + sids[n].offset + i * 4);
+							buffer[i] = efuse_read(ctx, sids[n].offset + i * 4);
 						printf("%s:(0x%04x %d-bits)", sids[n].name, sids[n].offset, sids[n].size_bits);
 						for(int i = 0; i < count; i++)
 						{
@@ -1652,11 +1706,56 @@ static int chip_extra(struct xfel_ctx_t * ctx, int argc, char * argv[])
 					}
 					return 1;
 				}
+				else if(!strcmp(argv[0], "read32") && (argc == 2))
+				{
+					uint32_t offset = strtoul(argv[1], NULL, 0);
+					printf("0x%08x\r\n", efuse_read(ctx, offset));
+					return 1;
+				}
+				else if(!strcmp(argv[0], "write32") && (argc == 3))
+				{
+					uint32_t offset = strtoul(argv[1], NULL, 0);
+					size_t value = strtoul(argv[2], NULL, 0);
+					efuse_write(ctx, offset, value);
+					return 1;
+				}
+				else if(!strcmp(argv[0], "write") && (argc == 2))
+				{
+					uint32_t offset = strtoul(argv[1], NULL, 0);
+					uint64_t len;
+					void * buf = file_load(argv[2], &len);
+					if(buf && (len > 0))
+					{
+						uint8_t * p = buf;
+						uint32_t l = len;
+						uint32_t o = 0;
+						uint32_t v;
+						while(l >= 4)
+						{
+							v = *((uint32_t *)p);
+							efuse_write(ctx, offset + o, v);
+							l -= 4;
+							o += 4;
+							p += 4;
+						}
+						if(l > 0)
+						{
+							uint32_t v = 0;
+							for(int i = 0; i < l; i++)
+								v = ((v << 8) & 0xffffff00) | p[i];
+							efuse_write(ctx, offset + o, v);
+						}
+						free(buf);
+					}
+				}
 			}
 		}
 	}
 	printf("usage:\r\n");
-	printf("    xfel extra efuse dump - Dump all of the efuse information\r\n");
+	printf("    xfel extra efuse dump                     - Dump all of the efuse information\r\n");
+	printf("    xfel extra efuse read32 <offset>          - Read 32-bits value from efuse\r\n");
+	printf("    xfel extra efuse write32 <offset> <value> - Write 32-bits value to efuse\r\n");
+	printf("    xfel extra efuse write <offset> <file>    - Write file to efuse\r\n");
 	return 0;
 }