On https://pdos.csail.mit.edu/6.828/2017/xv6/book-rev10.pdf (Draft as of August 29, 2017):

page 25: Some margin text is cropped

page 46: At the margin "IRQ_TIMER,+code" should probably be replaced by "IRQ_TIMER+code". Also in the index (page 105) "IRQ_TIMER,, 46" should be replaced by "IRQ_TIMER, 46" (one comma less)

page 82: Some margin text is cropped

Is there an easy way to generate a version of the book with reflowable text, like html or epub? Searching around, I found this page, so someone came up with some way of doing it. I tried fiddling with the Makefile and scripts to use troff -Thtml and dhtml instead of dpost. I was able to get valid html output but it had no formatting and no figures. I was not previously familiar with troff, but the syntax seems pretty straightforward. Perhaps a new troff->ReSructed Text converter would not be too hard to write (it seems like the link above was generated with sphinx and Restructured Text).

Issue

Some functions that are quoted in the book at the beginning of sentences start with an uppercase, some others don't.
I have already made a PR to correct the ones I could correct, but for other, this is probably due to the index where all functions need to have a lowercase.
I am not sure about the fix you prefer, but I think you should add a new macro in book.mac (there is already one that enables to index a name without writing it in the book, so it is possible, using .index function and then .code Function (like you did for Tvinit in trap.t l.282-283), to have a better behavior, but then "+code" would be missing in the sidebar...)

List

I will list here all the occurrences I find in the book (July 2019).

first.t

userinit (l.608, l. 629)
scheduler (l. 759)
allocuvm (l. 882)

mem.t

main (l. 205)
mappages (l. 231)
walkpgdir (l. 253)
kalloc (l. 419)
loaduvm (l. 555)

trap.t

argint (l. 581)
argptr (l. 614)
argstr (l. 625)
trap (l. 1011)

In

xv6-book/trap.t

Line 339 in cfe48f6

TODO: Replace SETGATE with real code.

TODO: Replace SETGATE with real code.

xv6-book/fs.t

Line 13 in cfe48f6

TODO: Explain the name sys_mknod.

TODO: Explain the name sys_mknod.

Perhaps someone wants "to really do the TODOs" so that they can be removed?

In trap.t, line 699 says:

xv6 programs to map interrupt 0 to IRQ 0

This sentence is not particularly clear. I would suggest:

During initialization, xv6 programs interrupt gates:
.code-index tvinit
.line trap.c:/^tvinit/
initialize entry 0 of IDT to vector0, and
so on.

In "Appendix B: The boot loader" there is a dummy text for the second exercise:

xv6-book/appboot.t

Lines 672 to 673 in a2b9e9a

	.exercise
	something about BIOS lasting longer + security problems

Perhaps you want to replace it by a "real" exercise or (less likely) remove the dummy text of this exercise.

In mem.t (lines 860-870), it is written:

but xv6 uses segments only for the common trick of
implementing per-cpu variables such as
.code proc
that are at a fixed address but have different values
on different CPUs (see
.code-index seginit ).
Implementations of per-CPU (or per-thread) storage on non-segment
architectures would dedicate a register to holding a pointer
to the per-CPU data area, but the x86 has so few general
registers that the extra effort required to use segmentation
is worthwhile.

As far as I understand, all segments in GDT/LDT start from 0 to ffffffff. Thus, they are not used for the described trick. Furthermore, proc is referenced through struct cpu in the cpus[] array (and index in this array is obtained by searching the local APICID).

Therefore, I suggest removing this whole paragraph.

Here the code lines pointed out after "unique pid" seem a little off from what's intended. My guess is that the intention was to specify (2488-2489), but due to the occurrence of EMBRYO in the comments preceding the allocproc function, the regex matched the wrong EMBRYO. Not sure what your favorite fix would be, but seems like it should be a pretty easy fix.