[SeaBIOS] investigate features differences between ovmf and seabios with QEMU

[Chen Fan]

Hi all,
    I'm a novice with OVMF, so please pardon me if I make any mistake.

    I have made a list about the feature differences between OVMF and
Seabios after investigation using QEMU. I simply use seabios source code
file name as the feature's name, then I made the following categorize
about OVMF supported/unsupported features. maybe there are some defects
at the list. and if this list miss some important features, please point
it out to me.
  I want to improve this list with you. so I'm welcome any comments and
suggestions.

Thanks,
Chen

-----------------------------------------------------------------------
  A: OVMF supports feature which seabios support it
     (This includes features which have similar bios)
-----------------------------------------------------------------------
  1. ata          2. blockcmd     3. dma         4. floppy
  5. pci          6. pic          7. ps2port     8. rtc
  9. timer        10. usb-ehci    11. usb-hid    12. usb-hub
  13. usb-msc     14. usb-uhci    15. virtio-blk 16. virtio-pci
  17. virtio-ring 18. virtio-scsi 19. pci bus    20. VGA-cirrus
  21. ISA bridge  22. PCI IRQs    23. ISA        24. pci crs
  25. mtrr        26. smbios      27. smp        28. suspend
  29. block       30. boot        31. cdrom      32. output
  33. resume      34. serial      35. usb        36. pciint
  37. optionroms  38. xen         39. vgahooks   40. PCI I/O protcol(pci
bios)
  41. DSDT table  42. SEC (post)  43. MADT table 44. font
  45. mouse       46. disk        47. kbd        48. clock
  49. memmap      50. Memory Allocation Services (pmm) 
  51. System table (biosvar)      52. FW_CFG 

P.S:
  the values ​​in parentheses represents the seabios feature.

---------------------------------------------------------------------
  B: OVMF does not support features which seabios support it
---------------------------------------------------------------------
  53. ahci        54. usb-ohci    55. esp-scsi   56. lsi-scsi
  57. magasas     58. usb-uas     59. usb-xhci   60. cpu-hotplug
  61. acpi-dbug   62. VGA-std     63. PIIX4 PM   64. pci-hotplug
  65. GPE         66. hpet        67. q35        68. pvpanic
  69. processor table             70. smm        71. pnp bios  
  72. gdb

---------------------------------------------------------------------
  C: OVMF does not need to support feature which seabios support
     (due to UEFI's spec/implementation)
---------------------------------------------------------------------
  73. ramdisk    74. lzma decoder  75. biostable   76. coreboot
  77. shadow     78. apm

  D: OVMF supports feature which is required by UEFI spec
  79. CSM        80. GPT           81. secureboot

---------------------------------------------------------------------
  E: OVMF does not support feature which is required by UEFI spec
---------------------------------------------------------------------
  82. i18n