diff options
-rw-r--r-- | documentation/kernel-dev/kernel-dev-advanced.xml | 70 | ||||
-rw-r--r-- | documentation/kernel-dev/kernel-dev-intro.xml | 87 |
2 files changed, 91 insertions, 66 deletions
diff --git a/documentation/kernel-dev/kernel-dev-advanced.xml b/documentation/kernel-dev/kernel-dev-advanced.xml index b754cb9791..8b626e5ec9 100644 --- a/documentation/kernel-dev/kernel-dev-advanced.xml +++ b/documentation/kernel-dev/kernel-dev-advanced.xml | |||
@@ -7,14 +7,14 @@ | |||
7 | <title>Working with Advanced Metadata</title> | 7 | <title>Working with Advanced Metadata</title> |
8 | 8 | ||
9 | <para> | 9 | <para> |
10 | In addition to configuration fragments and patches, the | 10 | In addition to supporting configuration fragments and patches, the |
11 | Yocto Project kernel tools support rich metadata that you can | 11 | Yocto Project kernel tools also support rich |
12 | use to define complex policies and BSP support. | 12 | <ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink> that you can |
13 | The purpose of the metadata and the tools to manage it, known as | 13 | use to define complex policies and Board Support Package (BSP) support. |
14 | The purpose of the Metadata and the tools that manage it, known as | ||
14 | the kern-tools (<filename>kern-tools-native_git.bb</filename>), is | 15 | the kern-tools (<filename>kern-tools-native_git.bb</filename>), is |
15 | to assist in managing the complexity of the configuration and sources | 16 | to help you manage the complexity of the configuration and sources |
16 | in support of multiple Board Support Packages (BSPs) and Linux kernel | 17 | used to support multiple BSPs and Linux kernel types. |
17 | types. | ||
18 | </para> | 18 | </para> |
19 | 19 | ||
20 | <para> | 20 | <para> |
@@ -602,7 +602,7 @@ git repository: | |||
602 | or <filename>meta/cfg/kernel-cache/</filename> if you are creating | 602 | or <filename>meta/cfg/kernel-cache/</filename> if you are creating |
603 | metadata in-tree as described in | 603 | metadata in-tree as described in |
604 | the "<link linkend='in-tree-metadata'>In-Tree Metadata</link>" section. | 604 | the "<link linkend='in-tree-metadata'>In-Tree Metadata</link>" section. |
605 | </para> | 605 | </para> |
606 | 606 | ||
607 | <para> | 607 | <para> |
608 | Original text: | 608 | Original text: |
@@ -920,12 +920,12 @@ will want to specify in the KERNEL_FEATURES variable of the Linux kernel recipe | |||
920 | <literallayout class='monospaced'> | 920 | <literallayout class='monospaced'> |
921 | # Include this kernel type fragment to get the standard features and | 921 | # Include this kernel type fragment to get the standard features and |
922 | # configuration values. | 922 | # configuration values. |
923 | 923 | ||
924 | # Include all standard features | 924 | # Include all standard features |
925 | include standard-nocfg.scc | 925 | include standard-nocfg.scc |
926 | 926 | ||
927 | kconf non-hardware standard.cfg | 927 | kconf non-hardware standard.cfg |
928 | 928 | ||
929 | # individual cfg block section | 929 | # individual cfg block section |
930 | include cfg/fs/devtmpfs.scc | 930 | include cfg/fs/devtmpfs.scc |
931 | include cfg/fs/debugfs.scc | 931 | include cfg/fs/debugfs.scc |
@@ -933,7 +933,7 @@ will want to specify in the KERNEL_FEATURES variable of the Linux kernel recipe | |||
933 | include cfg/fs/ext2.scc | 933 | include cfg/fs/ext2.scc |
934 | include cfg/fs/ext3.scc | 934 | include cfg/fs/ext3.scc |
935 | include cfg/fs/ext4.scc | 935 | include cfg/fs/ext4.scc |
936 | 936 | ||
937 | include cfg/net/ipv6.scc | 937 | include cfg/net/ipv6.scc |
938 | include cfg/net/ip_nf.scc | 938 | include cfg/net/ip_nf.scc |
939 | include cfg/net/ip6_nf.scc | 939 | include cfg/net/ip6_nf.scc |
@@ -967,7 +967,7 @@ fragments together with any patches you want to use for all Linux kernel builds | |||
967 | of the specified ktype. In short, ktypes are where you define a high-level | 967 | of the specified ktype. In short, ktypes are where you define a high-level |
968 | kernel policy. Syntactically, however, they are no different than features (see | 968 | kernel policy. Syntactically, however, they are no different than features (see |
969 | 3.3.3). preempt-rt, and tiny. The ktype is selected by the LINUX_KERNEL_TYPE | 969 | 3.3.3). preempt-rt, and tiny. The ktype is selected by the LINUX_KERNEL_TYPE |
970 | variable in the recipe (see 3.1). | 970 | variable in the recipe (see 3.1). |
971 | 971 | ||
972 | By way of example, the linux-yocto-3.4 tree defines three ktypes: standard, | 972 | By way of example, the linux-yocto-3.4 tree defines three ktypes: standard, |
973 | tiny, and preempt-rt. The standard kernel type includes the generic Linux kernel | 973 | tiny, and preempt-rt. The standard kernel type includes the generic Linux kernel |
@@ -983,12 +983,12 @@ not currently include any source changes, but it may in the future. | |||
983 | The standard ktype is defined by standard.scc: | 983 | The standard ktype is defined by standard.scc: |
984 | # Include this kernel type fragment to get the standard features and | 984 | # Include this kernel type fragment to get the standard features and |
985 | # configuration values. | 985 | # configuration values. |
986 | 986 | ||
987 | # Include all standard features | 987 | # Include all standard features |
988 | include standard-nocfg.scc | 988 | include standard-nocfg.scc |
989 | 989 | ||
990 | kconf non-hardware standard.cfg | 990 | kconf non-hardware standard.cfg |
991 | 991 | ||
992 | # individual cfg block section | 992 | # individual cfg block section |
993 | include cfg/fs/devtmpfs.scc | 993 | include cfg/fs/devtmpfs.scc |
994 | include cfg/fs/debugfs.scc | 994 | include cfg/fs/debugfs.scc |
@@ -996,7 +996,7 @@ The standard ktype is defined by standard.scc: | |||
996 | include cfg/fs/ext2.scc | 996 | include cfg/fs/ext2.scc |
997 | include cfg/fs/ext3.scc | 997 | include cfg/fs/ext3.scc |
998 | include cfg/fs/ext4.scc | 998 | include cfg/fs/ext4.scc |
999 | 999 | ||
1000 | include cfg/net/ipv6.scc | 1000 | include cfg/net/ipv6.scc |
1001 | include cfg/net/ip_nf.scc | 1001 | include cfg/net/ip_nf.scc |
1002 | include cfg/net/ip6_nf.scc | 1002 | include cfg/net/ip6_nf.scc |
@@ -1092,7 +1092,7 @@ Note: It is not strictly necessary to create a ktype scc file. The BSP file can | |||
1092 | <literallayout class='monospaced'> | 1092 | <literallayout class='monospaced'> |
1093 | fri2.scc: | 1093 | fri2.scc: |
1094 | kconf hardware fri2.cfg | 1094 | kconf hardware fri2.cfg |
1095 | 1095 | ||
1096 | include cfg/x86.scc | 1096 | include cfg/x86.scc |
1097 | include features/eg20t/eg20t.scc | 1097 | include features/eg20t/eg20t.scc |
1098 | include cfg/dmaengine.scc | 1098 | include cfg/dmaengine.scc |
@@ -1119,19 +1119,19 @@ Note: It is not strictly necessary to create a ktype scc file. The BSP file can | |||
1119 | define KMACHINE fri2 | 1119 | define KMACHINE fri2 |
1120 | define KTYPE standard | 1120 | define KTYPE standard |
1121 | define KARCH i386 | 1121 | define KARCH i386 |
1122 | 1122 | ||
1123 | include ktypes/standard/standard.scc | 1123 | include ktypes/standard/standard.scc |
1124 | branch fri2 | 1124 | branch fri2 |
1125 | 1125 | ||
1126 | git merge emgd-1.14 | 1126 | git merge emgd-1.14 |
1127 | 1127 | ||
1128 | include fri2.scc | 1128 | include fri2.scc |
1129 | 1129 | ||
1130 | # Extra fri2 configs above the minimal defined in fri2.scc | 1130 | # Extra fri2 configs above the minimal defined in fri2.scc |
1131 | include cfg/efi-ext.scc | 1131 | include cfg/efi-ext.scc |
1132 | include features/drm-emgd/drm-emgd.scc | 1132 | include features/drm-emgd/drm-emgd.scc |
1133 | include cfg/vesafb.scc | 1133 | include cfg/vesafb.scc |
1134 | 1134 | ||
1135 | # default policy for standard kernels | 1135 | # default policy for standard kernels |
1136 | include cfg/usb-mass-storage.scc | 1136 | include cfg/usb-mass-storage.scc |
1137 | </literallayout> | 1137 | </literallayout> |
@@ -1162,10 +1162,10 @@ Note: It is not strictly necessary to create a ktype scc file. The BSP file can | |||
1162 | define KMACHINE fri2 | 1162 | define KMACHINE fri2 |
1163 | define KTYPE tiny | 1163 | define KTYPE tiny |
1164 | define KARCH i386 | 1164 | define KARCH i386 |
1165 | 1165 | ||
1166 | include ktypes/tiny/tiny.scc | 1166 | include ktypes/tiny/tiny.scc |
1167 | branch fri2 | 1167 | branch fri2 |
1168 | 1168 | ||
1169 | include fri2.scc | 1169 | include fri2.scc |
1170 | </literallayout> | 1170 | </literallayout> |
1171 | As you might expect, the tiny description includes quite a bit less. | 1171 | As you might expect, the tiny description includes quite a bit less. |
@@ -1236,7 +1236,7 @@ BSP definitions from the linux-yocto-3.4 repository: | |||
1236 | 1236 | ||
1237 | fri2.scc: | 1237 | fri2.scc: |
1238 | kconf hardware fri2.cfg | 1238 | kconf hardware fri2.cfg |
1239 | 1239 | ||
1240 | include cfg/x86.scc | 1240 | include cfg/x86.scc |
1241 | include features/eg20t/eg20t.scc | 1241 | include features/eg20t/eg20t.scc |
1242 | include cfg/dmaengine.scc | 1242 | include cfg/dmaengine.scc |
@@ -1257,19 +1257,19 @@ fri2-standard.scc: | |||
1257 | define KMACHINE fri2 | 1257 | define KMACHINE fri2 |
1258 | define KTYPE standard | 1258 | define KTYPE standard |
1259 | define KARCH i386 | 1259 | define KARCH i386 |
1260 | 1260 | ||
1261 | include ktypes/standard/standard.scc | 1261 | include ktypes/standard/standard.scc |
1262 | branch fri2 | 1262 | branch fri2 |
1263 | 1263 | ||
1264 | git merge emgd-1.14 | 1264 | git merge emgd-1.14 |
1265 | 1265 | ||
1266 | include fri2.scc | 1266 | include fri2.scc |
1267 | 1267 | ||
1268 | # Extra fri2 configs above the minimal defined in fri2.scc | 1268 | # Extra fri2 configs above the minimal defined in fri2.scc |
1269 | include cfg/efi-ext.scc | 1269 | include cfg/efi-ext.scc |
1270 | include features/drm-emgd/drm-emgd.scc | 1270 | include features/drm-emgd/drm-emgd.scc |
1271 | include cfg/vesafb.scc | 1271 | include cfg/vesafb.scc |
1272 | 1272 | ||
1273 | # default policy for standard kernels | 1273 | # default policy for standard kernels |
1274 | include cfg/usb-mass-storage.scc | 1274 | include cfg/usb-mass-storage.scc |
1275 | 1275 | ||
@@ -1291,10 +1291,10 @@ fri2-tiny.scc: | |||
1291 | define KMACHINE fri2 | 1291 | define KMACHINE fri2 |
1292 | define KTYPE tiny | 1292 | define KTYPE tiny |
1293 | define KARCH i386 | 1293 | define KARCH i386 |
1294 | 1294 | ||
1295 | include ktypes/tiny/tiny.scc | 1295 | include ktypes/tiny/tiny.scc |
1296 | branch fri2 | 1296 | branch fri2 |
1297 | 1297 | ||
1298 | include fri2.scc | 1298 | include fri2.scc |
1299 | 1299 | ||
1300 | As you might expect, the tiny description includes quite a bit less. In fact, | 1300 | As you might expect, the tiny description includes quite a bit less. In fact, |
@@ -1435,9 +1435,9 @@ include them in the BSP description for the board(s) that require them (see | |||
1435 | Alternatively, you can create a branch in your Linux kernel sources and apply | 1435 | Alternatively, you can create a branch in your Linux kernel sources and apply |
1436 | the patches there. You can then specify this new branch as the KBRANCH to use | 1436 | the patches there. You can then specify this new branch as the KBRANCH to use |
1437 | for this board. You can do this in the recipe with the KBRANCH variable: | 1437 | for this board. You can do this in the recipe with the KBRANCH variable: |
1438 | 1438 | ||
1439 | KBRANCH = "mynewbranch" | 1439 | KBRANCH = "mynewbranch" |
1440 | 1440 | ||
1441 | or in the BSP description using the "branch" command: | 1441 | or in the BSP description using the "branch" command: |
1442 | 1442 | ||
1443 | mybsp.scc: | 1443 | mybsp.scc: |
diff --git a/documentation/kernel-dev/kernel-dev-intro.xml b/documentation/kernel-dev/kernel-dev-intro.xml index 67d8d93f08..32a4040e4b 100644 --- a/documentation/kernel-dev/kernel-dev-intro.xml +++ b/documentation/kernel-dev/kernel-dev-intro.xml | |||
@@ -3,44 +3,69 @@ | |||
3 | [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > | 3 | [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > |
4 | 4 | ||
5 | <chapter id='kernel-dev-intro'> | 5 | <chapter id='kernel-dev-intro'> |
6 | |||
7 | <title>Introduction</title> | 6 | <title>Introduction</title> |
8 | 7 | ||
9 | <para> | 8 | <section id='kernel-dev-overview'> |
10 | Regardless of how you intend to make use of the Yocto Project, | 9 | <title>Overview</title> |
11 | chances are you are going to need to work with the Linux kernel. | ||
12 | The Yocto Project provides a powerful set of tools for managing | ||
13 | Linux kernel sources and configuration data. | ||
14 | You can use this tooling to help you make a single configuration change, | ||
15 | apply a couple of patches, or work with your own sources. | ||
16 | </para> | ||
17 | |||
18 | <para> | ||
19 | The Yocto Project Kernel Development Manual describes common tasks | ||
20 | you can perform using the kernel tooling as well as provides information | ||
21 | about the metadata needed to work with the kernel inside the | ||
22 | Yocto Project. | ||
23 | </para> | ||
24 | |||
25 | <section id='kernel-dev-background'> | ||
26 | <title>Background</title> | ||
27 | 10 | ||
28 | <para> | 11 | <para> |
29 | Each Yocto Project release introduces a new set of linux-yocto | 12 | Regardless of how you intend to make use of the Yocto Project, |
30 | kernel recipes that tracks the latest upstream developments and | 13 | chances are you will work with the Linux kernel. |
31 | introduces newly supported platforms. | 14 | This manual provides background information on the Yocto Linux kernel |
32 | In addition to the new kernel recipes, the previous recipes are | 15 | <ulink url='&YOCTO_DOCS_DEV_URL;#metadata'>Metadata</ulink>, |
33 | refreshed and supported for at least one additional release. | 16 | describes common tasks you can perform using the kernel tools, |
17 | and shows you how to use the Metadata needed to work with | ||
18 | the kernel inside the Yocto Project. | ||
19 | </para> | ||
20 | |||
21 | <para> | ||
22 | Each Yocto Project release has a set of linux-yocto recipes, whose | ||
23 | Git repositories you can view in the Yocto | ||
24 | <ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink> under | ||
25 | the "Yocto Linux Kernel" heading. | ||
26 | New recipes for the release track the latest upstream developments | ||
27 | and introduce newly supported platforms. | ||
28 | Previous recipes in the release are refreshed and supported for at | ||
29 | least one additional release. | ||
34 | As they align, these previous releases are updated to include the | 30 | As they align, these previous releases are updated to include the |
35 | latest from the Long Term Support Initiative (LTSI) project. | 31 | latest from the Long Term Support Initiative (LTSI) project. |
36 | Besides these recipes, a <filename>linux-yocto-dev.bb</filename> | 32 | Also included is a linux-yocto development recipe |
37 | recipe is available for working with the very latest in upstream | 33 | (<filename>linux-yocto-dev.bb</filename>) should you want to work |
38 | Linux kernel development as well as metadata development. | 34 | with the very latest in upstream Linux kernel development and |
35 | Metadata development. | ||
36 | </para> | ||
37 | |||
38 | <para> | ||
39 | The Yocto Project also provides a powerful set of kernel | ||
40 | tools for managing Linux kernel sources and configuration data. | ||
41 | You can use these tools to make a single configuration change, | ||
42 | apply multiple patches, or work with your own kernel sources. | ||
43 | </para> | ||
44 | |||
45 | <para> | ||
46 | In particular, the kernel tools allow you to generate configuration | ||
47 | fragments that specify only what you must, and nothing more. | ||
48 | Configuration fragments only need to contain the highest level | ||
49 | visible <filename>CONFIG</filename> options as presented by the Linux | ||
50 | kernel <filename>menuconfig</filename> system. | ||
51 | Contrast this against a complete Linux kernel | ||
52 | <filename>.config</filename>, which includes all the automatically | ||
53 | selected <filename>CONFIG</filename> options. | ||
54 | This efficiency reduces your maintenance effort and allows you | ||
55 | to further separate your configuration in ways that make sense for | ||
56 | your project. | ||
57 | A common split separates policy and hardware. | ||
58 | For example, all your kernels might support | ||
59 | the <filename>proc</filename> and <filename>sys</filename> filesystems, | ||
60 | but only specific boards require sound, USB, or specific drivers. | ||
61 | Specifying these configurations individually allows you to aggregate | ||
62 | them together as needed, but maintains them in only one place. | ||
63 | Similar logic applies to separating source changes. | ||
39 | </para> | 64 | </para> |
40 | 65 | ||
41 | <para> | 66 | <para> |
42 | If you do not maintain your own kernel sources and need to make | 67 | If you do not maintain your own kernel sources and need to make |
43 | only minimal changes to the sources, these recipes provide a | 68 | only minimal changes to the sources, the released recipes provide a |
44 | vetted base upon which to layer your changes. | 69 | vetted base upon which to layer your changes. |
45 | Doing so allows you to benefit from the continual kernel | 70 | Doing so allows you to benefit from the continual kernel |
46 | integration and testing performed during development of the | 71 | integration and testing performed during development of the |
@@ -50,8 +75,8 @@ | |||
50 | <para> | 75 | <para> |
51 | If, instead, you have a very specific Linux kernel source tree | 76 | If, instead, you have a very specific Linux kernel source tree |
52 | and are unable to align with one of the many official linux-yocto | 77 | and are unable to align with one of the many official linux-yocto |
53 | releases, an alternative exists by which you can use the Yocto | 78 | recipes, an alternative exists by which you can use the Yocto |
54 | Project Linux kernel tools with your own sources. | 79 | Project Linux kernel tools with your own kernel sources. |
55 | </para> | 80 | </para> |
56 | </section> | 81 | </section> |
57 | 82 | ||
@@ -61,7 +86,7 @@ | |||
61 | <para> | 86 | <para> |
62 | The sections that follow provide instructions for completing | 87 | The sections that follow provide instructions for completing |
63 | specific Linux kernel development tasks. | 88 | specific Linux kernel development tasks. |
64 | These instructions assume you are familiar with working with | 89 | These instructions assume you are comfortable working with |
65 | <ulink url='http://developer.berlios.de/projects/bitbake/'>BitBake</ulink> | 90 | <ulink url='http://developer.berlios.de/projects/bitbake/'>BitBake</ulink> |
66 | recipes and basic open-source development tools. | 91 | recipes and basic open-source development tools. |
67 | Understanding these concepts will facilitate the process of working | 92 | Understanding these concepts will facilitate the process of working |