Skip to content

Boot-up B register values #75

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
dmitry-shechtman wants to merge 8 commits into
base: master
Choose a base branch
from
Open

Boot-up B register values #75

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
57a3af3
Add BOOTUP_B_DMG0
dmitry-shechtman Aug 12, 2025
8c9d6cd
Remove BOOTUP_B_CGB and BOOTUP_B_AGB
dmitry-shechtman Aug 12, 2025
79caa98
Merge branch 'dmg0' into b_squish
dmitry-shechtman Aug 12, 2025
f437856
Group boot-up B values
dmitry-shechtman Aug 12, 2025
36b77b2
Add BOOTUP_B_* to hardware_compat.inc
dmitry-shechtman Aug 12, 2025
492fd92
Merge branch 'b_agb' into b_squish
dmitry-shechtman Aug 12, 2025
debac99
Add explanation for BOOTUP_B_* removal
dmitry-shechtman Aug 13, 2025
9b07ed2
Merge branch 'gbdev:master' into b_squish
dmitry-shechtman Sep 3, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 2 additions & 3 deletions hardware.inc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1037,10 +1037,9 @@ def BOOTUP_A_MGB equ $FF
def BOOTUP_A_SGB equ BOOTUP_A_DMG
def BOOTUP_A_SGB2 equ BOOTUP_A_MGB

; Register B = CPU qualifier (if A is BOOTUP_A_CGB)
; Register B = CPU qualifier
def BOOTUP_B_DMG0 equ $FF
def B_BOOTUP_B_AGB equ 0

@Rangi42 Rangi42 Aug 4, 2026

Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
def B_BOOTUP_B_AGB equ 0
def B_BOOTUP_B_AGB equ 0 ; 0 = CGB, 1 = AGB

def BOOTUP_B_CGB equ 0 << B_BOOTUP_B_AGB
def BOOTUP_B_AGB equ 1 << B_BOOTUP_B_AGB

; Register C = CPU qualifier
def BOOTUP_C_DMG equ $13
Expand Down
5 changes: 5 additions & 0 deletions hardware_compat.inc
View file
Open in desktop
Comment thread
Rangi42 marked this conversation as resolved.
Original file line number Diff line number Diff line change
Expand Up @@ -385,6 +385,11 @@ def OAM_B equ OAM_SIZE

def BOOTUPB_B_AGB equ B_BOOTUP_B_AGB

; These values should not be relied upon; see

@avivace avivace Jan 1, 2026

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
; These values should not be relied upon; see
; Warning: these values should not be relied upon; see

; https://gbdev.io/pandocs/Power_Up_Sequence.html#cgbdmg_b
Comment on lines +388 to +389

@Rangi42 Rangi42 Aug 4, 2026

Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
; These values should not be relied upon; see
; https://gbdev.io/pandocs/Power_Up_Sequence.html#cgbdmg_b
; Warning: these values should not be relied upon; see
; https://gbdev.io/pandocs/Power_Up_Sequence.html#cpu-registers

def BOOTUP_B_CGB equ 0 << B_BOOTUP_B_AGB
def BOOTUP_B_AGB equ 1 << B_BOOTUP_B_AGB


;******************************************************************************
; Aliases
Expand Down
Loading