[PATCH] Confirm EN29LV800 bus, timing, and page size
Uncertain values now confirmed. If you're happy with the new EN29LV800 code I'll submit a combined patch with a Signed-off-by tag. --- flashchips.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/flashchips.c b/flashchips.c index b5be180..10b8dea 100644 --- a/flashchips.c +++ b/flashchips.c @@ -2166,15 +2166,15 @@ struct flashchip flashchips[] = { { .vendor = "EON", .name = "EN29LV800(B)(C)B", - .bustype = CHIP_BUSTYPE_UNKNOWN, + .bustype = CHIP_BUSTYPE_PARALLEL, .manufacture_id = EON_ID, .model_id = EN_29LV800B, .total_size = 1024, - .page_size = 1024, // TODO: check this + .page_size = 1024, .feature_bits = FEATURE_ADDR_AAA | FEATURE_EITHER_RESET, .tested = TEST_UNTESTED, .probe = probe_jedec, - .probe_timing = TIMING_ZERO, /* TODO: check Datasheet has no timing info specified */ + .probe_timing = TIMING_ZERO, .erase = NULL, .block_erasers = { @@ -2198,15 +2198,15 @@ struct flashchip flashchips[] = { { .vendor = "EON", .name = "EN29LV800(B)(C)T", - .bustype = CHIP_BUSTYPE_UNKNOWN, + .bustype = CHIP_BUSTYPE_PARALLEL, .manufacture_id = EON_ID, .model_id = EN_29LV800T, .total_size = 1024, - .page_size = 1024, // TODO: check this + .page_size = 1024, .feature_bits = FEATURE_ADDR_AAA | FEATURE_EITHER_RESET, .tested = TEST_UNTESTED, .probe = probe_jedec, - .probe_timing = TIMING_ZERO, /* TODO: check Datasheet has no timing info specified */ + .probe_timing = TIMING_ZERO, .erase = NULL, .block_erasers = { -- 1.6.3.3
On 2/5/10 4:29 PM, TJ wrote:
Uncertain values now confirmed.
If you're happy with the new EN29LV800 code I'll submit a combined patch with a Signed-off-by tag. --- flashchips.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/flashchips.c b/flashchips.c index b5be180..10b8dea 100644 --- a/flashchips.c +++ b/flashchips.c @@ -2166,15 +2166,15 @@ struct flashchip flashchips[] = { { .vendor = "EON", .name = "EN29LV800(B)(C)B", - .bustype = CHIP_BUSTYPE_UNKNOWN, + .bustype = CHIP_BUSTYPE_PARALLEL, .manufacture_id = EON_ID, .model_id = EN_29LV800B, .total_size = 1024, - .page_size = 1024, // TODO: check this + .page_size = 1024, .feature_bits = FEATURE_ADDR_AAA | FEATURE_EITHER_RESET, .tested = TEST_UNTESTED, .probe = probe_jedec, - .probe_timing = TIMING_ZERO, /* TODO: check Datasheet has no timing info specified */ + .probe_timing = TIMING_ZERO, .erase = NULL, .block_erasers = { @@ -2198,15 +2198,15 @@ struct flashchip flashchips[] = { { .vendor = "EON", .name = "EN29LV800(B)(C)T", - .bustype = CHIP_BUSTYPE_UNKNOWN, + .bustype = CHIP_BUSTYPE_PARALLEL, .manufacture_id = EON_ID, .model_id = EN_29LV800T, .total_size = 1024, - .page_size = 1024, // TODO: check this + .page_size = 1024, .feature_bits = FEATURE_ADDR_AAA | FEATURE_EITHER_RESET, .tested = TEST_UNTESTED, .probe = probe_jedec, - .probe_timing = TIMING_ZERO, /* TODO: check Datasheet has no timing info specified */ + .probe_timing = TIMING_ZERO, .erase = NULL, .block_erasers = {
EN29LV800 is not a JEDEC compatible chip, it uses an odd command sequence like the M29F400BT
On Fri, 2010-02-05 at 18:59 -0800, Sean Nelson wrote:
EN29LV800 is not a JEDEC compatible chip, it uses an odd command sequence like the M29F400BT
Are EON incorrect in the datasheet then, or is there a subtle distinction between what flashrom means with JEDEC and what EON mean? The datasheet says: • JEDEC Standard program and erase commands • JEDEC standard DATA polling and toggle bits feature I saw the custom probe functions for EN29F512 and EN29F002A but wasn't clear that would be needed although I did see they match the datasheet probe sequence. I compared the probes to the datasheets because the code questions how to exit autoselect mode and my reading of it is that it only needs a: chip_writeb(0xF0, bios + 0x555); // write address can be any value since the datasheets say "The system must write the reset command to exit the autoselect mode and return to reading array data" and the same for interrupting erase/program modes. Does it follow that the erase/write operations will also need custom functions if JEDEC isn't really supported? I guess I need to get up to speed on JEDEC and the rest of flashrom - I only came across flashrom last night in pursuit of some clues for manipulating Phoenix BIOS settings.
On 2/5/10 8:05 PM, TJ wrote:
On Fri, 2010-02-05 at 18:59 -0800, Sean Nelson wrote:
EN29LV800 is not a JEDEC compatible chip, it uses an odd command sequence like the M29F400BT
Are EON incorrect in the datasheet then, or is there a subtle distinction between what flashrom means with JEDEC and what EON mean?
The datasheet says:
• JEDEC Standard program and erase commands • JEDEC standard DATA polling and toggle bits feature
I saw the custom probe functions for EN29F512 and EN29F002A but wasn't clear that would be needed although I did see they match the datasheet probe sequence.
I compared the probes to the datasheets because the code questions how to exit autoselect mode and my reading of it is that it only needs a:
chip_writeb(0xF0, bios + 0x555); // write address can be any value
since the datasheets say "The system must write the reset command to exit the autoselect mode and return to reading array data" and the same for interrupting erase/program modes.
Does it follow that the erase/write operations will also need custom functions if JEDEC isn't really supported?
I guess I need to get up to speed on JEDEC and the rest of flashrom - I only came across flashrom last night in pursuit of some clues for manipulating Phoenix BIOS settings.
_______________________________________________ flashrom mailing list flashrom@flashrom.org http://www.flashrom.org/mailman/listinfo/flashrom JEDEC has a 5555/2AAA/5555 command sequence, where as EON uses a AAA/555/AAA. Our code is byte based.
Hi TJ, thanks for your EN29LV800 patches. The caveat mentioned by Sean is indeed something important. Looking at the EN29LV800 datasheet, you'll find the following description: "8 Megabit (1024K x 8-bit / 512K x 16-bit) Flash Memory" This indicates a dual-mode flash, and that means you have to use different addresses for commands depending on whether you're using that chip in 8-bit or 16-bit mode. Table 5 (EN29LV800 Command Definitions) in said datasheet lists command addresses for Word mode and Byte mode. Word mode uses standard JEDEC addresses, but Byte mode uses JEDEC addresses shifted left by 1 bit. These flash chips are wired to 8 bit on x86 mainboards, so you have to pick the command addresses in Byte mode. On 06.02.2010 10:29, Sean Nelson wrote:
On 2/5/10 8:05 PM, TJ wrote:
On Fri, 2010-02-05 at 18:59 -0800, Sean Nelson wrote:
EN29LV800 is not a JEDEC compatible chip, it uses an odd command sequence like the M29F400BT
Are EON incorrect in the datasheet then, or is there a subtle distinction between what flashrom means with JEDEC and what EON mean?
The datasheet says:
• JEDEC Standard program and erase commands • JEDEC standard DATA polling and toggle bits feature
JEDEC has a 5555/2AAA/5555 command sequence, where as EON uses a AAA/555/AAA. Our code is byte based.
m29f400bt.c is very similar to jedec.c, but it uses JEDEC addresses left shifted by 1 bit, so I think using the functions in that file should mostly work. There might be a need to rewrite the erase/write functions to be more generic (well, to look similar to those in jedec.c instead of hard-coding the eraseblock layout). A good start to copy the flash chip definition from is probably the M29F400BT entry. If you decide to modify your current patch instead, please make sure to adjust the .feature_bits and to remove the .erase line (the latter has been eliminated in latest flashrom). I hope this explanation was helpful for you. If possible, please provide one combined patch for the EN29LF800 against latest flashrom, and add your signoff. That makes it easier to review and apply the patch. If you believe the patch is not ready yet, just mention that in the mail and we'll wait with applying and/or do a more thorough review. Regards, Carl-Daniel -- "I do consider assignment statements and pointer variables to be among computer science's most valuable treasures." -- Donald E. Knuth
This is based on TJ's patches from 2010, see http://patchwork.coreboot.org/patch/883/ http://patchwork.coreboot.org/patch/884/ I have rebased and combined them, added voltages, corrected the names and verified the erase block layouts. Someone else needs to review/change the parallel-specific parts, because i have no idea about all those jedec vs. 3-byte vs. shifted problems (and i actually do not want to know :P). -- Kind regards/Mit freundlichen Grüßen, Stefan Tauner
participants (4)
-
Carl-Daniel Hailfinger -
Sean Nelson -
Stefan Tauner -
TJ