xref: /openbmc/u-boot/tools/buildman/README (revision 3765b3e7)
1# Copyright (c) 2013 The Chromium OS Authors.
2#
3# SPDX-License-Identifier:	GPL-2.0+
4#
5
6What is this?
7=============
8
9This tool handles building U-Boot to check that you have not broken it
10with your patch series. It can build each individual commit and report
11which boards fail on which commits, and which errors come up. It aims
12to make full use of multi-processor machines.
13
14A key feature of buildman is its output summary, which allows warnings,
15errors or image size increases in a particular commit or board to be
16quickly identified and the offending commit pinpointed. This can be a big
17help for anyone working with >10 patches at a time.
18
19
20Caveats
21=======
22
23Buildman is still in its infancy. It is already a very useful tool, but
24expect to find problems and send patches.
25
26Buildman can be stopped and restarted, in which case it will continue
27where it left off. This should happen cleanly and without side-effects.
28If not, it is a bug, for which a patch would be welcome.
29
30Buildman gets so tied up in its work that it can ignore the outside world.
31You may need to press Ctrl-C several times to quit it. Also it will print
32out various exceptions when stopped.
33
34
35Theory of Operation
36===================
37
38(please read this section in full twice or you will be perpetually confused)
39
40Buildman is a builder. It is not make, although it runs make. It does not
41produce any useful output on the terminal while building, except for
42progress information. All the output (errors, warnings and binaries if you
43are ask for them) is stored in output directories, which you can look at
44while the build is progressing, or when it is finished.
45
46Buildman produces a concise summary of which boards succeeded and failed.
47It shows which commit introduced which board failure using a simple
48red/green colour coding. Full error information can be requested, in which
49case it is de-duped and displayed against the commit that introduced the
50error. An example workflow is below.
51
52Buildman stores image size information and can report changes in image size
53from commit to commit. An example of this is below.
54
55Buildman starts multiple threads, and each thread builds for one board at
56a time. A thread starts at the first commit, configures the source for your
57board and builds it. Then it checks out the next commit and does an
58incremental build. Eventually the thread reaches the last commit and stops.
59If errors or warnings are found along the way, the thread will reconfigure
60after every commit, and your build will be very slow. This is because a
61file that produces just a warning would not normally be rebuilt in an
62incremental build.
63
64Buildman works in an entirely separate place from your U-Boot repository.
65It creates a separate working directory for each thread, and puts the
66output files in the working directory, organised by commit name and board
67name, in a two-level hierarchy.
68
69Buildman is invoked in your U-Boot directory, the one with the .git
70directory. It clones this repository into a copy for each thread, and the
71threads do not affect the state of your git repository. Any checkouts done
72by the thread affect only the working directory for that thread.
73
74Buildman automatically selects the correct toolchain for each board. You
75must supply suitable toolchains, but buildman takes care of selecting the
76right one.
77
78Buildman always builds a branch, and always builds the upstream commit as
79well, for comparison. It cannot build individual commits at present, unless
80(maybe) you point it at an empty branch. Put all your commits in a branch,
81set the branch's upstream to a valid value, and all will be well. Otherwise
82buildman will perform random actions. Use -n to check what the random
83actions might be.
84
85Buildman is optimised for building many commits at once, for many boards.
86On multi-core machines, Buildman is fast because it uses most of the
87available CPU power. When it gets to the end, or if you are building just
88a few commits or boards, it will be pretty slow. As a tip, if you don't
89plan to use your machine for anything else, you can use -T to increase the
90number of threads beyond the default.
91
92Buildman lets you build all boards, or a subset. Specify the subset using
93the board name, architecture name, SOC name, or anything else in the
94boards.cfg file. So 'at91' will build all AT91 boards (arm), powerpc will
95build all PowerPC boards.
96
97Buildman does not store intermediate object files. It optionally copies
98the binary output into a directory when a build is successful. Size
99information is always recorded. It needs a fair bit of disk space to work,
100typically 250MB per thread.
101
102
103Setting up
104==========
105
1061. Get the U-Boot source. You probably already have it, but if not these
107steps should get you started with a repo and some commits for testing.
108
109$ cd /path/to/u-boot
110$ git clone git://git.denx.de/u-boot.git .
111$ git checkout -b my-branch origin/master
112$ # Add some commits to the branch, reading for testing
113
1142. Create ~/.buildman to tell buildman where to find tool chains. As an
115example:
116
117# Buildman settings file
118
119[toolchain]
120root: /
121rest: /toolchains/*
122eldk: /opt/eldk-4.2
123
124[toolchain-alias]
125x86: i386
126blackfin: bfin
127sh: sh4
128nds32: nds32le
129openrisc: or32
130
131
132This selects the available toolchain paths. Add the base directory for
133each of your toolchains here. Buildman will search inside these directories
134and also in any '/usr' and '/usr/bin' subdirectories.
135
136Make sure the tags (here root: rest: and eldk:) are unique.
137
138The toolchain-alias section indicates that the i386 toolchain should be used
139to build x86 commits.
140
141
1422. Check the available toolchains
143
144Run this check to make sure that you have a toolchain for every architecture.
145
146$ ./tools/buildman/buildman --list-tool-chains
147Scanning for tool chains
148   - scanning path '/'
149      - looking in '/.'
150      - looking in '/bin'
151      - looking in '/usr/bin'
152         - found '/usr/bin/gcc'
153Tool chain test:  OK
154         - found '/usr/bin/c89-gcc'
155Tool chain test:  OK
156         - found '/usr/bin/c99-gcc'
157Tool chain test:  OK
158         - found '/usr/bin/x86_64-linux-gnu-gcc'
159Tool chain test:  OK
160   - scanning path '/toolchains/powerpc-linux'
161      - looking in '/toolchains/powerpc-linux/.'
162      - looking in '/toolchains/powerpc-linux/bin'
163         - found '/toolchains/powerpc-linux/bin/powerpc-linux-gcc'
164Tool chain test:  OK
165      - looking in '/toolchains/powerpc-linux/usr/bin'
166   - scanning path '/toolchains/nds32le-linux-glibc-v1f'
167      - looking in '/toolchains/nds32le-linux-glibc-v1f/.'
168      - looking in '/toolchains/nds32le-linux-glibc-v1f/bin'
169         - found '/toolchains/nds32le-linux-glibc-v1f/bin/nds32le-linux-gcc'
170Tool chain test:  OK
171      - looking in '/toolchains/nds32le-linux-glibc-v1f/usr/bin'
172   - scanning path '/toolchains/nios2'
173      - looking in '/toolchains/nios2/.'
174      - looking in '/toolchains/nios2/bin'
175         - found '/toolchains/nios2/bin/nios2-linux-gcc'
176Tool chain test:  OK
177         - found '/toolchains/nios2/bin/nios2-linux-uclibc-gcc'
178Tool chain test:  OK
179      - looking in '/toolchains/nios2/usr/bin'
180         - found '/toolchains/nios2/usr/bin/nios2-linux-gcc'
181Tool chain test:  OK
182         - found '/toolchains/nios2/usr/bin/nios2-linux-uclibc-gcc'
183Tool chain test:  OK
184   - scanning path '/toolchains/microblaze-unknown-linux-gnu'
185      - looking in '/toolchains/microblaze-unknown-linux-gnu/.'
186      - looking in '/toolchains/microblaze-unknown-linux-gnu/bin'
187         - found '/toolchains/microblaze-unknown-linux-gnu/bin/microblaze-unknown-linux-gnu-gcc'
188Tool chain test:  OK
189         - found '/toolchains/microblaze-unknown-linux-gnu/bin/mb-linux-gcc'
190Tool chain test:  OK
191      - looking in '/toolchains/microblaze-unknown-linux-gnu/usr/bin'
192   - scanning path '/toolchains/mips-linux'
193      - looking in '/toolchains/mips-linux/.'
194      - looking in '/toolchains/mips-linux/bin'
195         - found '/toolchains/mips-linux/bin/mips-linux-gcc'
196Tool chain test:  OK
197      - looking in '/toolchains/mips-linux/usr/bin'
198   - scanning path '/toolchains/old'
199      - looking in '/toolchains/old/.'
200      - looking in '/toolchains/old/bin'
201      - looking in '/toolchains/old/usr/bin'
202   - scanning path '/toolchains/i386-linux'
203      - looking in '/toolchains/i386-linux/.'
204      - looking in '/toolchains/i386-linux/bin'
205         - found '/toolchains/i386-linux/bin/i386-linux-gcc'
206Tool chain test:  OK
207      - looking in '/toolchains/i386-linux/usr/bin'
208   - scanning path '/toolchains/bfin-uclinux'
209      - looking in '/toolchains/bfin-uclinux/.'
210      - looking in '/toolchains/bfin-uclinux/bin'
211         - found '/toolchains/bfin-uclinux/bin/bfin-uclinux-gcc'
212Tool chain test:  OK
213      - looking in '/toolchains/bfin-uclinux/usr/bin'
214   - scanning path '/toolchains/sparc-elf'
215      - looking in '/toolchains/sparc-elf/.'
216      - looking in '/toolchains/sparc-elf/bin'
217         - found '/toolchains/sparc-elf/bin/sparc-elf-gcc'
218Tool chain test:  OK
219      - looking in '/toolchains/sparc-elf/usr/bin'
220   - scanning path '/toolchains/arm-2010q1'
221      - looking in '/toolchains/arm-2010q1/.'
222      - looking in '/toolchains/arm-2010q1/bin'
223         - found '/toolchains/arm-2010q1/bin/arm-none-linux-gnueabi-gcc'
224Tool chain test:  OK
225      - looking in '/toolchains/arm-2010q1/usr/bin'
226   - scanning path '/toolchains/from'
227      - looking in '/toolchains/from/.'
228      - looking in '/toolchains/from/bin'
229      - looking in '/toolchains/from/usr/bin'
230   - scanning path '/toolchains/sh4-gentoo-linux-gnu'
231      - looking in '/toolchains/sh4-gentoo-linux-gnu/.'
232      - looking in '/toolchains/sh4-gentoo-linux-gnu/bin'
233         - found '/toolchains/sh4-gentoo-linux-gnu/bin/sh4-gentoo-linux-gnu-gcc'
234Tool chain test:  OK
235      - looking in '/toolchains/sh4-gentoo-linux-gnu/usr/bin'
236   - scanning path '/toolchains/avr32-linux'
237      - looking in '/toolchains/avr32-linux/.'
238      - looking in '/toolchains/avr32-linux/bin'
239         - found '/toolchains/avr32-linux/bin/avr32-gcc'
240Tool chain test:  OK
241      - looking in '/toolchains/avr32-linux/usr/bin'
242   - scanning path '/toolchains/m68k-linux'
243      - looking in '/toolchains/m68k-linux/.'
244      - looking in '/toolchains/m68k-linux/bin'
245         - found '/toolchains/m68k-linux/bin/m68k-linux-gcc'
246Tool chain test:  OK
247      - looking in '/toolchains/m68k-linux/usr/bin'
248List of available toolchains (17):
249arm       : /toolchains/arm-2010q1/bin/arm-none-linux-gnueabi-gcc
250avr32     : /toolchains/avr32-linux/bin/avr32-gcc
251bfin      : /toolchains/bfin-uclinux/bin/bfin-uclinux-gcc
252c89       : /usr/bin/c89-gcc
253c99       : /usr/bin/c99-gcc
254i386      : /toolchains/i386-linux/bin/i386-linux-gcc
255m68k      : /toolchains/m68k-linux/bin/m68k-linux-gcc
256mb        : /toolchains/microblaze-unknown-linux-gnu/bin/mb-linux-gcc
257microblaze: /toolchains/microblaze-unknown-linux-gnu/bin/microblaze-unknown-linux-gnu-gcc
258mips      : /toolchains/mips-linux/bin/mips-linux-gcc
259nds32le   : /toolchains/nds32le-linux-glibc-v1f/bin/nds32le-linux-gcc
260nios2     : /toolchains/nios2/bin/nios2-linux-gcc
261powerpc   : /toolchains/powerpc-linux/bin/powerpc-linux-gcc
262sandbox   : /usr/bin/gcc
263sh4       : /toolchains/sh4-gentoo-linux-gnu/bin/sh4-gentoo-linux-gnu-gcc
264sparc     : /toolchains/sparc-elf/bin/sparc-elf-gcc
265x86_64    : /usr/bin/x86_64-linux-gnu-gcc
266
267
268You can see that everything is covered, even some strange ones that won't
269be used (c88 and c99). This is a feature.
270
271
272How to run it
273=============
274
275First do a dry run using the -n flag: (replace <branch> with a real, local
276branch with a valid upstream)
277
278$ ./tools/buildman/buildman -b <branch> -n
279
280If it can't detect the upstream branch, try checking out the branch, and
281doing something like 'git branch --set-upstream <branch> upstream/master'
282or something similar.
283
284As an exmmple:
285
286Dry run, so not doing much. But I would do this:
287
288Building 18 commits for 1059 boards (4 threads, 1 job per thread)
289Build directory: ../lcd9b
290    5bb3505 Merge branch 'master' of git://git.denx.de/u-boot-arm
291    c18f1b4 tegra: Use const for pinmux_config_pingroup/table()
292    2f043ae tegra: Add display support to funcmux
293    e349900 tegra: fdt: Add pwm binding and node
294    424a5f0 tegra: fdt: Add LCD definitions for Tegra
295    0636ccf tegra: Add support for PWM
296    a994fe7 tegra: Add SOC support for display/lcd
297    fcd7350 tegra: Add LCD driver
298    4d46e9d tegra: Add LCD support to Nvidia boards
299    991bd48 arm: Add control over cachability of memory regions
300    54e8019 lcd: Add CONFIG_LCD_ALIGNMENT to select frame buffer alignment
301    d92aff7 lcd: Add support for flushing LCD fb from dcache after update
302    dbd0677 tegra: Align LCD frame buffer to section boundary
303    0cff9b8 tegra: Support control of cache settings for LCD
304    9c56900 tegra: fdt: Add LCD definitions for Seaboard
305    5cc29db lcd: Add CONFIG_CONSOLE_SCROLL_LINES option to speed console
306    cac5a23 tegra: Enable display/lcd support on Seaboard
307    49ff541 wip
308
309Total boards to build for each commit: 1059
310
311This shows that it will build all 1059 boards, using 4 threads (because
312we have a 4-core CPU). Each thread will run with -j1, meaning that each
313make job will use a single CPU. The list of commits to be built helps you
314confirm that things look about right. Notice that buildman has chosen a
315'base' directory for you, immediately above your source tree.
316
317Buildman works entirely inside the base directory, here ../lcd9b,
318creating a working directory for each thread, and creating output
319directories for each commit and board.
320
321
322Suggested Workflow
323==================
324
325To run the build for real, take off the -n:
326
327$ ./tools/buildman/buildman -b <branch>
328
329Buildman will set up some working directories, and get started. After a
330minute or so it will settle down to a steady pace, with a display like this:
331
332Building 18 commits for 1059 boards (4 threads, 1 job per thread)
333  528   36  124 /19062  1:13:30  : SIMPC8313_SP
334
335This means that it is building 19062 board/commit combinations. So far it
336has managed to succesfully build 528. Another 36 have built with warnings,
337and 124 more didn't build at all. Buildman expects to complete the process
338in an hour and 15 minutes. Use this time to buy a faster computer.
339
340
341To find out how the build went, ask for a summary with -s. You can do this
342either before the build completes (presumably in another terminal) or or
343afterwards. Let's work through an example of how this is used:
344
345$ ./tools/buildman/buildman -b lcd9b -s
346...
34701: Merge branch 'master' of git://git.denx.de/u-boot-arm
348   powerpc:   + galaxy5200_LOWBOOT
34902: tegra: Use const for pinmux_config_pingroup/table()
35003: tegra: Add display support to funcmux
35104: tegra: fdt: Add pwm binding and node
35205: tegra: fdt: Add LCD definitions for Tegra
35306: tegra: Add support for PWM
35407: tegra: Add SOC support for display/lcd
35508: tegra: Add LCD driver
35609: tegra: Add LCD support to Nvidia boards
35710: arm: Add control over cachability of memory regions
35811: lcd: Add CONFIG_LCD_ALIGNMENT to select frame buffer alignment
35912: lcd: Add support for flushing LCD fb from dcache after update
360       arm:   + lubbock
36113: tegra: Align LCD frame buffer to section boundary
36214: tegra: Support control of cache settings for LCD
36315: tegra: fdt: Add LCD definitions for Seaboard
36416: lcd: Add CONFIG_CONSOLE_SCROLL_LINES option to speed console
36517: tegra: Enable display/lcd support on Seaboard
36618: wip
367
368This shows which commits have succeeded and which have failed. In this case
369the build is still in progress so many boards are not built yet (use -u to
370see which ones). But still we can see a few failures. The galaxy5200_LOWBOOT
371never builds correctly. This could be a problem with our toolchain, or it
372could be a bug in the upstream. The good news is that we probably don't need
373to blame our commits. The bad news is it isn't tested on that board.
374
375Commit 12 broke lubbock. That's what the '+ lubbock' means. The failure
376is never fixed by a later commit, or you would see lubbock again, in green,
377without the +.
378
379To see the actual error:
380
381$ ./tools/buildman/buildman -b <branch> -se lubbock
382...
38312: lcd: Add support for flushing LCD fb from dcache after update
384       arm:   + lubbock
385+common/libcommon.o: In function `lcd_sync':
386+/u-boot/lcd9b/.bm-work/00/common/lcd.c:120: undefined reference to `flush_dcache_range'
387+arm-none-linux-gnueabi-ld: BFD (Sourcery G++ Lite 2010q1-202) 2.19.51.20090709 assertion fail /scratch/julian/2010q1-release-linux-lite/obj/binutils-src-2010q1-202-arm-none-linux-gnueabi-i686-pc-linux-gnu/bfd/elf32-arm.c:12572
388+make: *** [/u-boot/lcd9b/.bm-work/00/build/u-boot] Error 139
38913: tegra: Align LCD frame buffer to section boundary
39014: tegra: Support control of cache settings for LCD
39115: tegra: fdt: Add LCD definitions for Seaboard
39216: lcd: Add CONFIG_CONSOLE_SCROLL_LINES option to speed console
393-/u-boot/lcd9b/.bm-work/00/common/lcd.c:120: undefined reference to `flush_dcache_range'
394+/u-boot/lcd9b/.bm-work/00/common/lcd.c:125: undefined reference to `flush_dcache_range'
39517: tegra: Enable display/lcd support on Seaboard
39618: wip
397
398So the problem is in lcd.c, due to missing cache operations. This information
399should be enough to work out what that commit is doing to break these
400boards. (In this case pxa did not have cache operations defined).
401
402If you see error lines marked with - that means that the errors were fixed
403by that commit. Sometimes commits can be in the wrong order, so that a
404breakage is introduced for a few commits and fixed by later commits. This
405shows up clearly with buildman. You can then reorder the commits and try
406again.
407
408At commit 16, the error moves - you can see that the old error at line 120
409is fixed, but there is a new one at line 126. This is probably only because
410we added some code and moved the broken line futher down the file.
411
412If many boards have the same error, then -e will display the error only
413once. This makes the output as concise as possible.
414
415The full build output in this case is available in:
416
417../lcd9b/12_of_18_gd92aff7_lcd--Add-support-for/lubbock/
418
419   done: Indicates the build was done, and holds the return code from make.
420         This is 0 for a good build, typically 2 for a failure.
421
422   err:  Output from stderr, if any. Errors and warnings appear here.
423
424   log:  Output from stdout. Normally there isn't any since buildman runs
425         in silent mode for now.
426
427   toolchain: Shows information about the toolchain used for the build.
428
429   sizes: Shows image size information.
430
431It is possible to get the build output there also. Use the -k option for
432this. In that case you will also see some output files, like:
433
434   System.map  toolchain  u-boot  u-boot.bin  u-boot.map  autoconf.mk
435   (also SPL versions u-boot-spl and u-boot-spl.bin if available)
436
437
438Checking Image Sizes
439====================
440
441A key requirement for U-Boot is that you keep code/data size to a minimum.
442Where a new feature increases this noticeably it should normally be put
443behind a CONFIG flag so that boards can leave it off and keep the image
444size more or less the same with each new release.
445
446To check the impact of your commits on image size, use -S. For example:
447
448$ ./tools/buildman/buildman -b us-x86 -sS
449Summary of 10 commits for 1066 boards (4 threads, 1 job per thread)
45001: MAKEALL: add support for per architecture toolchains
45102: x86: Add function to get top of usable ram
452       x86: (for 1/3 boards)  text -272.0  rodata +41.0
45303: x86: Add basic cache operations
45404: x86: Permit bootstage and timer data to be used prior to relocation
455       x86: (for 1/3 boards)  data +16.0
45605: x86: Add an __end symbol to signal the end of the U-Boot binary
457       x86: (for 1/3 boards)  text +76.0
45806: x86: Rearrange the output input to remove BSS
459       x86: (for 1/3 boards)  bss -2140.0
46007: x86: Support relocation of FDT on start-up
461       x86: +   coreboot-x86
46208: x86: Add error checking to x86 relocation code
46309: x86: Adjust link device tree include file
46410: x86: Enable CONFIG_OF_CONTROL on coreboot
465
466
467You can see that image size only changed on x86, which is good because this
468series is not supposed to change any other board. From commit 7 onwards the
469build fails so we don't get code size numbers. The numbers are fractional
470because they are an average of all boards for that architecture. The
471intention is to allow you to quickly find image size problems introduced by
472your commits.
473
474Note that the 'text' region and 'rodata' are split out. You should add the
475two together to get the total read-only size (reported as the first column
476in the output from binutil's 'size' utility).
477
478A useful option is --step which lets you skip some commits. For example
479--step 2 will show the image sizes for only every 2nd commit (so it will
480compare the image sizes of the 1st, 3rd, 5th... commits). You can also use
481--step 0 which will compare only the first and last commits. This is useful
482for an overview of how your entire series affects code size.
483
484You can also use -d to see a detailed size breakdown for each board. This
485list is sorted in order from largest growth to largest reduction.
486
487It is possible to go a little further with the -B option (--bloat). This
488shows where U-Boot has bloted, breaking the size change down to the function
489level. Example output is below:
490
491$ ./tools/buildman/buildman -b us-mem4 -sSdB
492...
49319: Roll crc32 into hash infrastructure
494       arm: (for 10/10 boards)  all -143.4  bss +1.2  data -4.8  rodata -48.2 text -91.6
495            paz00          :  all +23  bss -4  rodata -29  text +56
496               u-boot: add: 1/0, grow: 3/-2 bytes: 168/-104 (64)
497                 function                                   old     new   delta
498                 hash_command                                80     160     +80
499                 crc32_wd_buf                                 -      56     +56
500                 ext4fs_read_file                           540     568     +28
501                 insert_var_value_sub                       688     692      +4
502                 run_list_real                             1996    1992      -4
503                 do_mem_crc                                 168      68    -100
504            trimslice      :  all -9  bss +16  rodata -29  text +4
505               u-boot: add: 1/0, grow: 1/-3 bytes: 136/-124 (12)
506                 function                                   old     new   delta
507                 hash_command                                80     160     +80
508                 crc32_wd_buf                                 -      56     +56
509                 ext4fs_iterate_dir                         672     668      -4
510                 ext4fs_read_file                           568     548     -20
511                 do_mem_crc                                 168      68    -100
512            whistler       :  all -9  bss +16  rodata -29  text +4
513               u-boot: add: 1/0, grow: 1/-3 bytes: 136/-124 (12)
514                 function                                   old     new   delta
515                 hash_command                                80     160     +80
516                 crc32_wd_buf                                 -      56     +56
517                 ext4fs_iterate_dir                         672     668      -4
518                 ext4fs_read_file                           568     548     -20
519                 do_mem_crc                                 168      68    -100
520            seaboard       :  all -9  bss -28  rodata -29  text +48
521               u-boot: add: 1/0, grow: 3/-2 bytes: 160/-104 (56)
522                 function                                   old     new   delta
523                 hash_command                                80     160     +80
524                 crc32_wd_buf                                 -      56     +56
525                 ext4fs_read_file                           548     568     +20
526                 run_list_real                             1996    2000      +4
527                 do_nandboot                                760     756      -4
528                 do_mem_crc                                 168      68    -100
529            colibri_t20_iris:  all -9  rodata -29  text +20
530               u-boot: add: 1/0, grow: 2/-3 bytes: 140/-112 (28)
531                 function                                   old     new   delta
532                 hash_command                                80     160     +80
533                 crc32_wd_buf                                 -      56     +56
534                 read_abs_bbt                               204     208      +4
535                 do_nandboot                                760     756      -4
536                 ext4fs_read_file                           576     568      -8
537                 do_mem_crc                                 168      68    -100
538            ventana        :  all -37  bss -12  rodata -29  text +4
539               u-boot: add: 1/0, grow: 1/-3 bytes: 136/-124 (12)
540                 function                                   old     new   delta
541                 hash_command                                80     160     +80
542                 crc32_wd_buf                                 -      56     +56
543                 ext4fs_iterate_dir                         672     668      -4
544                 ext4fs_read_file                           568     548     -20
545                 do_mem_crc                                 168      68    -100
546            harmony        :  all -37  bss -16  rodata -29  text +8
547               u-boot: add: 1/0, grow: 2/-3 bytes: 140/-124 (16)
548                 function                                   old     new   delta
549                 hash_command                                80     160     +80
550                 crc32_wd_buf                                 -      56     +56
551                 nand_write_oob_syndrome                    428     432      +4
552                 ext4fs_iterate_dir                         672     668      -4
553                 ext4fs_read_file                           568     548     -20
554                 do_mem_crc                                 168      68    -100
555            medcom-wide    :  all -417  bss +28  data -16  rodata -93  text -336
556               u-boot: add: 1/-1, grow: 1/-2 bytes: 88/-376 (-288)
557                 function                                   old     new   delta
558                 crc32_wd_buf                                 -      56     +56
559                 do_fat_read_at                            2872    2904     +32
560                 hash_algo                                   16       -     -16
561                 do_mem_crc                                 168      68    -100
562                 hash_command                               420     160    -260
563            tec            :  all -449  bss -4  data -16  rodata -93  text -336
564               u-boot: add: 1/-1, grow: 1/-2 bytes: 88/-376 (-288)
565                 function                                   old     new   delta
566                 crc32_wd_buf                                 -      56     +56
567                 do_fat_read_at                            2872    2904     +32
568                 hash_algo                                   16       -     -16
569                 do_mem_crc                                 168      68    -100
570                 hash_command                               420     160    -260
571            plutux         :  all -481  bss +16  data -16  rodata -93  text -388
572               u-boot: add: 1/-1, grow: 1/-3 bytes: 68/-408 (-340)
573                 function                                   old     new   delta
574                 crc32_wd_buf                                 -      56     +56
575                 do_load_serial_bin                        1688    1700     +12
576                 hash_algo                                   16       -     -16
577                 do_fat_read_at                            2904    2872     -32
578                 do_mem_crc                                 168      68    -100
579                 hash_command                               420     160    -260
580   powerpc: (for 5/5 boards)  all +37.4  data -3.2  rodata -41.8  text +82.4
581            MPC8610HPCD    :  all +55  rodata -29  text +84
582               u-boot: add: 1/0, grow: 0/-1 bytes: 176/-96 (80)
583                 function                                   old     new   delta
584                 hash_command                                 -     176    +176
585                 do_mem_crc                                 184      88     -96
586            MPC8641HPCN    :  all +55  rodata -29  text +84
587               u-boot: add: 1/0, grow: 0/-1 bytes: 176/-96 (80)
588                 function                                   old     new   delta
589                 hash_command                                 -     176    +176
590                 do_mem_crc                                 184      88     -96
591            MPC8641HPCN_36BIT:  all +55  rodata -29  text +84
592               u-boot: add: 1/0, grow: 0/-1 bytes: 176/-96 (80)
593                 function                                   old     new   delta
594                 hash_command                                 -     176    +176
595                 do_mem_crc                                 184      88     -96
596            sbc8641d       :  all +55  rodata -29  text +84
597               u-boot: add: 1/0, grow: 0/-1 bytes: 176/-96 (80)
598                 function                                   old     new   delta
599                 hash_command                                 -     176    +176
600                 do_mem_crc                                 184      88     -96
601            xpedite517x    :  all -33  data -16  rodata -93  text +76
602               u-boot: add: 1/-1, grow: 0/-1 bytes: 176/-112 (64)
603                 function                                   old     new   delta
604                 hash_command                                 -     176    +176
605                 hash_algo                                   16       -     -16
606                 do_mem_crc                                 184      88     -96
607...
608
609
610This shows that commit 19 has increased text size for arm (although only one
611board was built) and by 96 bytes for powerpc. This increase was offset in both
612cases by reductions in rodata and data/bss.
613
614Shown below the summary lines is the sizes for each board. Below each board
615is the sizes for each function. This information starts with:
616
617   add - number of functions added / removed
618   grow - number of functions which grew / shrunk
619   bytes - number of bytes of code added to / removed from all functions,
620            plus the total byte change in brackets
621
622The change seems to be that hash_command() has increased by more than the
623do_mem_crc() function has decreased. The function sizes typically add up to
624roughly the text area size, but note that every read-only section except
625rodata is included in 'text', so the function total does not exactly
626correspond.
627
628It is common when refactoring code for the rodata to decrease as the text size
629increases, and vice versa.
630
631
632Providing 'make' flags
633======================
634
635U-Boot's build system supports a few flags (such as BUILD_TAG) which affect
636the build product. These flags can be specified in the buildman settings
637file. They can also be useful when building U-Boot against other open source
638software.
639
640[make-flags]
641at91-boards=ENABLE_AT91_TEST=1
642snapper9260=${at91-boards} BUILD_TAG=442
643snapper9g45=${at91-boards} BUILD_TAG=443
644
645This will use 'make ENABLE_AT91_TEST=1 BUILD_TAG=442' for snapper9260
646and 'make ENABLE_AT91_TEST=1 BUILD_TAG=442' for snapper9g45. A special
647variable ${target} is available to access the target name (snapper9260 and
648snapper9g20 in this case). Variables are resolved recursively.
649
650It is expected that any variables added are dealt with in U-Boot's
651config.mk file and documented in the README.
652
653
654Other options
655=============
656
657Buildman has various other command line options. Try --help to see them.
658
659
660TODO
661====
662
663This has mostly be written in my spare time as a response to my difficulties
664in testing large series of patches. Apart from tidying up there is quite a
665bit of scope for improvement. Things like better error diffs, easier access
666to log files, error display while building. Also it would be nice it buildman
667could 'hunt' for problems, perhaps by building a few boards for each arch,
668or checking commits for changed files and building only boards which use
669those files.
670
671
672Credits
673=======
674
675Thanks to Grant Grundler <grundler@chromium.org> for his ideas for improving
676the build speed by building all commits for a board instead of the other
677way around.
678
679
680
681Simon Glass
682sjg@chromium.org
683Halloween 2012
684Updated 12-12-12
685Updated 23-02-13
686