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diff --git a/Lesson_32/README.md b/Lesson_32/README.md index 7eea2b3..d142384 100644 --- a/Lesson_32/README.md +++ b/Lesson_32/README.md @@ -142,3 +142,166 @@ $ make bin-x86_64-efi/ipxe.efi # EFI app with all devices $ make bin-x86_64-efi/808610de.efirom # EFI ROM vendev: 8086:10de $ make bin/808610de.rom # Legacy ROM vendev: 8086:10de ``` + +# EfiRom + +``` +$ EfiRom -h +Usage: EfiRom -f VendorId -i DeviceId [options] [file name<s>] + +Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved. + +Options: + -o FileName, --output FileName + File will be created to store the output content. + -e EfiFileName + EFI PE32 image files. + -ec EfiFileName + EFI PE32 image files and will be compressed. + -b BinFileName + Legacy binary files. + -l ClassCode + Hex ClassCode in the PCI data structure header. + -r Rev Hex Revision in the PCI data structure header. + -n Not to automatically set the LAST bit in the last file. + -f VendorId + Hex PCI Vendor ID for the device OpROM, must be specified + -i DeviceId + One or more hex PCI Device IDs for the device OpROM, must be specified + -p, --pci23 + Default layout meets PCI 3.0 specifications + specifying this flag will for a PCI 2.3 layout. + -d, --dump + Dump the headers of an existing option ROM image. + -v, --verbose + Turn on verbose output with informational messages. + --version Show program's version number and exit. + -h, --help + Show this help message and exit. + -q, --quiet + Disable all messages except FATAL ERRORS. + --debug [#,0-9] + Enable debug messages at level #. +``` +Complete version of the manual is placed at https://github.com/tianocore/edk2/blob/master/BaseTools/UserManuals/EfiRom_Utility_Man_Page.rtf + +If you are interested in the source code: https://github.com/tianocore/edk2/tree/master/BaseTools/Source/C/EfiRom + +With this tool it is possible to: +- dump Option ROM images +- create ROM images from a EFI drivers and/or Legacy binary images + +https://edk2-docs.gitbook.io/edk-ii-uefi-driver-writer-s-guide/18_pci_driver_design_guidelines/readme.7 +https://edk2-docs.gitbook.io/edk-ii-basetools-user-guides/efirom + + + +# VGA rom + +SeaBIOS is an open-source legacy BIOS implementation that implements the standard BIOS calling interfaces that a typical x86 proprietary BIOS implements (https://github.com/coreboot/seabios). +SeaVGABIOS is a sub-project of the SeaBIOS project - it is an open source implementation of a 16bit X86 VGA BIOS +(https://github.com/coreboot/seabios/blob/master/docs/SeaVGABIOS.md). In other words it builds a Legacy Option ROM for a PCI graphic device. + +SeaBIOS uses Kconfig system for the build configuration. Main options for the VGA BIOS are placed under https://github.com/coreboot/seabios/blob/master/vgasrc/Kconfig In this file you can see that one of the options is a OptionROM with a Vendor/Device pair as `1234:1111`. Exactly the one that we saw at QEMU: +``` + config VGA_VID + depends on VGA_PCI + hex + prompt "PCI Vendor ID" if OVERRIDE_PCI_ID + default 0x1013 if VGA_CIRRUS + default 0x1002 if VGA_ATI + default 0x1234 if VGA_BOCHS_STDVGA + default 0x15ad if VGA_BOCHS_VMWARE + default 0x1b36 if VGA_BOCHS_QXL + default 0x1af4 if VGA_BOCHS_VIRTIO + default 0x100b if VGA_GEODEGX2 + default 0x1022 if VGA_GEODELX + default 0x1234 if DISPLAY_BOCHS <-------------- + default 0x0000 + help + Vendor ID for the PCI ROM + + config VGA_DID + depends on VGA_PCI + hex + prompt "PCI Vendor ID" if OVERRIDE_PCI_ID + default 0x00b8 if VGA_CIRRUS + default 0x5159 if VGA_ATI + default 0x1111 if VGA_BOCHS_STDVGA + default 0x0405 if VGA_BOCHS_VMWARE + default 0x0100 if VGA_BOCHS_QXL + default 0x1050 if VGA_BOCHS_VIRTIO + default 0x0030 if VGA_GEODEGX2 + default 0x2081 if VGA_GEODELX + default 0x1111 if DISPLAY_BOCHS <--------------- + default 0x0000 + help + Device ID for the PCI ROM +``` +If you wonder what is `DISPLAY_BOCHS`, here is a help for this option: +``` + config DISPLAY_BOCHS + depends on QEMU + bool "qemu bochs-display support" + select VGA_EMULATE_TEXT + help + Build support for the qemu bochs-display device, which + is basically qemu stdvga without the legacy vga + emulation, supporting only 16+32 bpp VESA video modes + in a linear framebuffer. So this uses cbvga text mode + emulation. + + The bochs-display device is available in qemu + v3.0+. The vgabios works with the qemu stdvga too (use + "qemu -device VGA,romfile=/path/to/vgabios.bin")". +``` + +Let's build this SeaBIOS VGA image. Install necessary packages, download SeaBIOS source and perfrorm build configuration: +``` +$ sudo apt-get install python +$ git clone https://github.com/coreboot/seabios.git +$ cd seabios +$ make menuconfig +``` +In a menuconfig select: +``` +VGA ROM ---> VGA Hardware Type (qemu bochs-display support) +``` +After that execute: +``` +$ make +``` + +After the build resulting VGA Option ROM would be at path `out/vgabios.bin`. As `EfiRom` expects ROM files to have a `*.rom` extension, create a copy of a file with such extension. After that execute `dump` command on this file: +``` +$ cp out/vgabios.bin out/vgabios.rom +$ EfiRom -d out/vgabios.rom +Image 1 -- Offset 0x0 + ROM header contents + Signature 0xAA55 + PCIR offset 0x6E00 + Signature PCIR + Vendor ID 0x1234 + Device ID 0x1111 + Length 0x0018 + Revision 0x0000 + DeviceListOffset 0x00 + Class Code 0x030000 + Image size 0x7000 + Code revision: 0x0001 + MaxRuntimeImageLength 0x00 + ConfigUtilityCodeHeaderOffset 0x9066 + DMTFCLPEntryPointOffset 0x9066 + Indicator 0x80 (last image) + Code type 0x00 +``` +This is the info similar to the one that we saw with our utility on a working QEMU system. You can see that PCI vendor/device pair is set to `1234:1111`. + +# How QEMU gets these OptionROMs + +The main Makefile in QEMU responsible for OptionROM image creation is https://github.com/qemu/qemu/blob/master/roms/Makefile + +In this Makefile you can see how: +- `seavgabios-%` target is used for the creation of a Legacy SeaVGABIOS OptionROM +- `efi-rom-%` target is used for the creation of an OptionROM with both Legacy and UEFI iPXE code images (it even uses `EfiRom` utility from edk2 for this purpose) + |