| The SeaBIOS code can be built using standard GNU tools. A recent Linux |
| distribution should be able to build SeaBIOS using the standard |
| compiler tools. |
| |
| Building SeaBIOS |
| ================ |
| |
| First, [obtain the code](Download). SeaBIOS can be compiled for |
| several different build targets. It is also possible to configure |
| additional compile time options - run **make menuconfig** to do this. |
| |
| Build for QEMU (along with KVM, Xen, and Bochs) |
| ----------------------------------------------- |
| |
| To build for QEMU (and similar), one should be able to run "make" in |
| the main directory. The resulting file "out/bios.bin" contains the |
| processed bios image. |
| |
| One can use the resulting binary with QEMU by using QEMU's "-bios" |
| option. For example: |
| |
| `qemu -bios out/bios.bin -fda myfdimage.img` |
| |
| One can also use the resulting binary with Bochs. For example: |
| |
| `bochs -q 'floppya: 1_44=myfdimage.img' 'romimage: file=out/bios.bin'` |
| |
| Build for coreboot |
| ------------------ |
| |
| To build for coreboot please see the coreboot build instructions at: |
| <http://www.coreboot.org/SeaBIOS> |
| |
| Build as a UEFI Compatibility Support Module (CSM) |
| -------------------------------------------------- |
| |
| To build as a CSM, first run kconfig (make menuconfig) and enable |
| CONFIG_CSM. Then build SeaBIOS (make) - the resulting binary will be |
| in "out/Csm16.bin". |
| |
| This binary may be used with the OMVF/EDK-II UEFI firmware. It will |
| provide "legacy" BIOS services for booting non-EFI operating systems |
| and will also allow OVMF to display on otherwise unsupported video |
| hardware by using the traditional VGA BIOS. (Windows 2008r2 is known |
| to use INT 10h BIOS calls even when booted via EFI, and the presence |
| of a CSM makes this work as expected too.) |
| |
| Having built SeaBIOS with CONFIG_CSM, one should be able to drop the |
| result (out/Csm16.bin) into an OVMF build tree at |
| OvmfPkg/Csm/Csm16/Csm16.bin and then build OVMF with 'build -D |
| CSM_ENABLE'. The SeaBIOS binary will be included as a discrete file |
| within the 'Flash Volume' which is created, and there are tools which |
| will extract it and allow it to be replaced. |
| |
| Overview of files in the repository |
| =================================== |
| |
| The **src/** directory contains the main bios source code. The |
| **src/hw/** directory contains source code specific to hardware |
| drivers. The **src/fw/** directory contains source code for platform |
| firmware initialization. The **src/std/** directory contains header |
| files describing standard bios, firmware, and hardware interfaces. |
| |
| The **vgasrc/** directory contains code for VGA BIOS implementations. |
| This code is separate from the main BIOS code in the src/ directory. |
| When the build is configured to produce a VGA BIOS the resulting |
| binary is found in out/vgabios.bin. The VGA BIOS code is always |
| compiled in 16bit mode. |
| |
| The **scripts/** directory contains helper utilities for manipulating |
| and building the final roms. |
| |
| The **out/** directory is created by the build process - it contains |
| all intermediate and final files. |
| |
| When reading the C code be aware that code that runs in 16bit mode can |
| not arbitrarily access non-stack memory - see [Memory Model](Memory |
| Model) for more details. For information on the major C code functions |
| and where code execution starts see [Execution and code |
| flow](Execution and code flow). |
