The GPT standard requires that we reserve either 34 512 sectors, or 6 4k
sectors before starting partitions. However, we don't currently don't
enforce these minimums. This is 2 sectors + 16k of space.
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Details
Details
The old code produces
00000200 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...| 00000210 ea c7 2f 95 00 00 00 00 01 00 00 00 00 00 00 00 |../.............| 00000220 04 60 09 00 00 00 00 00 03 00 00 00 00 00 00 00 |.`..............| 00000230 02 60 09 00 00 00 00 00 12 7a a9 63 4a f6 ed 11 |.`.......z.cJ...| 00000240 a7 d3 e0 d5 5e 1e 73 bd 02 00 00 00 00 00 00 00 |....^.s.........| 00000250 04 00 00 00 80 00 00 00 58 9c b0 81 00 00 00 00 |........X.......|
Which has 3 is the FirstLBA and 4 as the number of entries.
The correct output I claim is:
00000200 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...|
00000210 d8 2e 74 5a 00 00 00 00 01 00 00 00 00 00 00 00 |..tZ............|
00000220 42 60 09 00 00 00 00 00 22 00 00 00 00 00 00 00 |B`......".......|
00000230 21 60 09 00 00 00 00 00 84 7b f1 cc 98 6c ee 11 |!`.......{...l..|
00000240 a8 54 a0 36 9f 09 4f 1e 02 00 00 00 00 00 00 00 |.T.6..O.........|
00000250 80 00 00 00 80 00 00 00 71 5c 49 7b 00 00 00 00 |........q\I{....|which has first LBA is 0x22 / 34 and num entires of 0x80 / 128. These are the desired values.
Diff Detail
Diff Detail
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Buildable 54049 Build 50939: arc lint + arc unit
Event Timeline
Comment Actions
braino: min will return the smaller number. We want it to return the
larger of the computed size and the minimal size.
| sys/sys/disk/gpt.h | ||
|---|---|---|
| 87 | ||
| usr.bin/mkimg/gpt.c | ||
|---|---|---|
| 131 | I find this function a little confusing as written, but that predates and is independent of your change. | |
| usr.bin/mkimg/gpt.c | ||
|---|---|---|
| 131 | Yea... we need a roundup macro... | |
| usr.bin/mkimg/gpt.c | ||
|---|---|---|
| 29 | param comes before all headers other than cdefs, though not really sure why cdefs is included in the first place (left over from $FreeBSD$?), and there should be a blank line between the sys/ and non-sys/ includes anyway, so this isn't exactly the most style-conforming already | |
| 131 | howmany from sys/param.h? #define howmany(x, y) (((x)+((y)-1))/(y)) | |
| usr.bin/mkimg/gpt.c | ||
|---|---|---|
| 29 | Indeed cdefs is not needed. Changing the first include to #include <sys/param.h> results in an identical binary (other than debug info). | |
Comment Actions
It would be really good to get (some version of) this into the tree and on the build machine before the next RC build.
CC releng
Comment Actions
Update headers included, use howmany and improve (I claim) the comments
and commit message (which isn't updated automatically, alas)
Comment Actions
which isn't updated automatically, alas
You can edit it through the Phab web UI though.
| usr.bin/mkimg/gpt.c | ||
|---|---|---|
| 141 | No. Sector sizes are required to be a power of 2. There's no rounding needed. I think elsewhere we don't bother... And I'd like to keep the number of 'one more things' to a minimum. Not sure what a 16k sector size would do, or how larger sector sizes would work here. But both a 16k and 64k sector size would result in this returning 1. The standard is silent on sector sizes that aren't 512 or 4k. | |
| usr.bin/mkimg/gpt.c | ||
|---|---|---|
| 141 | It's not secsz I was thinking about, but GPT_MIN_RESERVED. 16384 is (obviously) a power of two, but the constant is defined elsewhere and so it's not immediately obvious when looking at this expression. | |