Unified hypervisor image for multiple processor ISAs
A method for booting a computer system includes: loading a first stage bootloader of a plurality of first stage bootloaders from a boot image based on a known configuration of the computer system; executing the first stage bootloader to identify a selected bootbank of a plurality of bootbanks in the boot image based on the known configuration of the computer system; executing, by the first stage bootloader, a second stage bootloader from the boot image with an instruction to boot from the selected bootbank; and executing, by the second stage bootloader, a binary file in the selected bootbank.
1. A method for booting a computer system, comprising:
loading a first stage bootloader of a plurality of first stage bootloaders from a boot image based on a known configuration of the computer system;
executing the first stage bootloader to identify a selected bootbank of a plurality of bootbanks in the boot image based on the known configuration of the computer system;
executing, by the first stage bootloader, a second stage bootloader from the boot image with an instruction to boot from the selected bootbank; and
executing, by the second stage bootloader, a binary file in the selected bootbank.
2. The method of claim 1 , wherein the boot image is a compound boot image, and wherein each of the plurality of bootbanks is associated with a different corresponding computer system configuration.
3. The method of claim 2 , wherein each of the plurality of bootbanks includes a corresponding architecture variable that specifies a computer system configuration associated with the bootbank.
4. The method of claim 3 , wherein the first stage bootloader identifies the selected bootbank in the boot image by:
searching the architecture variables of the plurality of bootbanks to identify an architecture variable that specifies a computer system configuration compatible with the known configuration of the computer system.
5. The method of claim 4 , wherein the plurality of bootbanks have a hierarchy within the boot image based on complexity of the computer system configurations specified by the architecture variables.
6. The method of claim 5 , wherein the first stage bootloader identifies the selected bootbank having an architecture variable that specifies a computer system configuration compatible with the known configuration of the computer system, and having the highest complexity within the hierarchy.
7. The method of claim 3 , wherein the architecture variable specifies whether the computer system configuration boots in exception level 1 (EL1) or exception level 2 (EL2) of a processor of the computer system.
8. The method of claim 1 , wherein the first stage bootloader is loaded by:
searching the boot image for a first stage bootloader file in response to the computer system having a first known configuration; and
searching the boot image for another first stage bootloader file in response to the computer system having a second known configuration.
9. The method of claim 8 , wherein the first stage bootloader executes the second stage bootloader from the boot image by:
searching the boot image for a second stage bootloader file in response to the computer system having the first known configuration; and
searching the boot image for another second stage bootloader file in response to the computer system having the second known configuration.
10. The method of claim 1 , wherein the computer system retrieves the boot image from an external memory.
11. A non-transitory computer readable medium comprising instructions for booting a computer system, wherein the instructions, when executed by the computer system, cause the computer system to:
load a first stage bootloader of a plurality of first stage bootloaders from a boot image based on a known configuration of the computer system;
execute the first stage bootloader to identify a selected bootbank of a plurality of bootbanks in the boot image based on the known configuration of the computer system;
execute, by the first stage bootloader, a second stage bootloader from the boot image with an instruction to boot from the selected bootbank; and
execute, by the second stage bootloader, a binary file in the selected bootbank.
12. The non-transitory computer readable medium of claim 11 , wherein the boot image is a compound boot image, and wherein each of the plurality of bootbanks is associated with a different corresponding computer system configuration.
13. The non-transitory computer readable medium of claim 12 , wherein each of the plurality of bootbanks includes a corresponding architecture variable that specifies a computer system configuration associated with the bootbank.
14. The non-transitory computer readable medium of claim 13 , wherein the first stage bootloader identifies the selected bootbank in the boot image by searching the architecture variables of the plurality of bootbanks to identify an architecture variable that specifies a computer system configuration compatible with the known configuration of the computer system.
15. The non-transitory computer readable medium of claim 13 , wherein the architecture variable specifies whether the computer system configuration boots in exception level 1 (EL1) or exception level 2 (EL2) of a processor of the computer system.
16. A computer system, comprising:
a system memory; and
a processor configured to carry out the steps of:
loading a first stage bootloader of a plurality of first stage bootloaders from a boot image based on a known configuration of the computer system;
executing the first stage bootloader to identify a selected bootbank of a plurality of bootbanks in the boot image based on the known configuration of the computer system;
executing, by the first stage bootloader, a second stage bootloader from the boot image with an instruction to boot from the selected bootbank; and
executing, by the second stage bootloader, a binary file in the selected bootbank.
17. The computer system of claim 16 , wherein the boot image is a compound boot image, and wherein each of the plurality of bootbanks is associated with a different corresponding computer system configuration.
18. The computer system of claim 17 , wherein each of the plurality of bootbanks includes a corresponding architecture variable that specifies a computer system configuration associated with the bootbank.
19. The computer system of claim 18 , wherein the first stage bootloader identifies the selected bootbank in the boot image by searching the architecture variables of the plurality of bootbanks to identify an architecture variable that specifies a computer system configuration compatible with the known configuration of the computer system.
20. The computer system of claim 18 , wherein the architecture variable specifies whether the computer system configuration boots in exception level 1 (EL1) or exception level 2 (EL2) of the processor of the computer system.