diff options
Diffstat (limited to 'documentation/kernel-dev')
| -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 |
