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|
In the last lesson to build our app we've included its *.inf file as a component to the other package and have built this package. It is clearly not a good solution and in this lesson we will create our own package.
First lets remove our app from the `OvmfPkg/OvmfPkgX64.dsc` file:
```
################################################################################
[Components]
- SimplestApp/SimplestApp.inf
OvmfPkg/ResetVector/ResetVector.inf
```
Then create `UefiLessonsPkg` folder in the edk2 directory and move our app into this folder:
```
mkdir UefiLessonsPkg
mv SimplestApp UefiLessonsPkg/SimplestApp
```
Then we need to create platform description file (DSC) for our newly created package:
```
$ vi UefiLessonsPkg/UefiLessonsPkg.dsc
[Defines]
DSC_SPECIFICATION = 0x0001001C
PLATFORM_GUID = 3db7270f-ffac-4139-90a4-0ae68f3f8167
PLATFORM_VERSION = 0.01
PLATFORM_NAME = UefiLessonsPkg
SKUID_IDENTIFIER = DEFAULT
SUPPORTED_ARCHITECTURES = X64
BUILD_TARGETS = RELEASE
[Components]
UefiLessonsPkg/SimplestApp/SimplestApp.inf
```
All the fileds under `Defines` section are mondatory.
Full specification for the Platform Description (DSC) File can be found under https://edk2-docs.gitbook.io/edk-ii-dsc-specification/
Let's try to build our SimplestApp module that is now in our own package:
```
$ . edksetup.sh
$ build --platform=UefiLessonsPkg/UefiLessonsPkg.dsc \
--module=UefiLessonsPkg/SimplestApp/SimplestApp.inf \
--arch=X64 \
--buildtarget=RELEASE \
--tagname=GCC5
```
Unfortunately the build would fail:
```
build.py...
/home/kostr/edk2/UefiLessonsPkg/UefiLessonsPkg.dsc(...): error 4000: Instance of library class [UefiApplicationEntryPoint] is not found
in [/home/kostr/edk2/UefiLessonsPkg/SimplestApp/SimplestApp.inf] [X64]
consumed by module [/home/kostr/edk2/UefiLessonsPkg/SimplestApp/SimplestApp.inf]
```
To fix this we need to add `UefiApplicationEntryPoint` to the `LibraryClasses` section in our `UefiLessonsPkg.dsc` file.
To find necessay include lets search our edk2 codebase:
```
$ grep UefiApplicationEntryPoint -r ./ --include=*.inf | grep LIBRARY_CLASS
./MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf: LIBRARY_CLASS = UefiApplicationEntryPoint|UEFI_APPLICATION
```
Therefore we need to add these strings to our *.dsc file:
```
[LibraryClasses]
UefiApplicationEntryPoint|MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf
```
Format of the record is
```
LibraryClassName|Path/To/LibInstanceName.inf
```
LibraryClass can have several potential realizations (instances), therefore we need to write both `LibraryClassName` and `LibraryInstanceName`.
In the end this adds this string to the Makefile:
```
LIBS = $(LIBS) $(LIB_DIR)/$(LibInstanceName)
```
You can read more about `LibraryClasses` section under https://edk2-docs.gitbook.io/edk-ii-dsc-specification/2_dsc_overview/26_-libraryclasses-_section_processing
Let's try to rebuild:
```
$ build --platform=UefiLessonsPkg/UefiLessonsPkg.dsc \
--module=UefiLessonsPkg/SimplestApp/SimplestApp.inf \
--arch=X64 \
--buildtarget=RELEASE \
--tagname=GCC5
```
But the build would fail again:
```
build.py...
/home/kostr/tiano/edk2/UefiLessonsPkg/UefiLessonsPkg.dsc(...): error 4000: Instance of library class [UefiBootServicesTableLib] is not found
in [/home/kostr/tiano/edk2/MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf] [X64]
consumed by module [/home/kostr/tiano/edk2/UefiLessonsPkg/SimplestApp/SimplestApp.inf]
```
As we see the error message is the same. It seems like `UefiApplicationEntryPoint` module that we've included needs some additional includes. So we search necessary libraries again... and again... and again.
In the end our *.dsc file would be looking like this:
```
[Defines]
PLATFORM_NAME = UefiLessonsPkg
PLATFORM_GUID = 3db7270f-ffac-4139-90a4-0ae68f3f8167
PLATFORM_VERSION = 0.01
DSC_SPECIFICATION = 0x00010006
OUTPUT_DIRECTORY = Build/UefiLessonsPkg
SUPPORTED_ARCHITECTURES = X64
BUILD_TARGETS = RELEASE
SKUID_IDENTIFIER = DEFAULT
[LibraryClasses]
UefiApplicationEntryPoint|MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf
UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
DebugLib|MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf
BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
RegisterFilterLib|MdePkg/Library/RegisterFilterLibNull/RegisterFilterLibNull.inf
PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
DebugPrintErrorLevelLib|MdePkg/Library/BaseDebugPrintErrorLevelLib/BaseDebugPrintErrorLevelLib.inf
[Components]
UefiLessonsPkg/SimplestApp/SimplestApp.inf
```
After the successful build the result binary would be in a `Build/UefiLessonsPkg/RELEASE_GCC5/X64` folder:
```
$ ls -lh Build/UefiLessonsPkg/RELEASE_GCC5/X64/SimplestApp.efi
-rw-r--r-- 1 kostr kostr 960 Jun 13 12:47 Build/UefiLessonsPkg/RELEASE_GCC5/X64/SimplestApp.efi
```
Let's copy in our `UEFI_disk` folder and run it in OVMF:
```
$ cp Build/UefiLessonsPkg/RELEASE_GCC5/X64/SimplestApp.efi ~/UEFI_disk/
$ qemu-system-x86_64 -drive if=pflash,format=raw,file=Build/OvmfX64/RELEASE_GCC5/FV/OVMF.fd \
-drive format=raw,file=fat:rw:~/UEFI_disk \
-nographic \
-net none
```
Hopefully everything would be the same it was earlier:
```
UEFI Interactive Shell v2.2
EDK II
UEFI v2.70 (EDK II, 0x00010000)
Mapping table
FS0: Alias(s):HD0a1:;BLK1:
PciRoot(0x0)/Pci(0x1,0x1)/Ata(0x0)/HD(1,MBR,0xBE1AFDFA,0x3F,0xFBFC1)
BLK0: Alias(s):
PciRoot(0x0)/Pci(0x1,0x1)/Ata(0x0)
BLK2: Alias(s):
PciRoot(0x0)/Pci(0x1,0x1)/Ata(0x0)
Press ESC in 4 seconds to skip startup.nsh or any other key to continue.
Shell> fs0:
FS0:\> SimplestApp.efi
FS0:\>
```
|
