Seems a new version of the GBA, DS, DSi and potentially one day 3ds emulator known as no$gba dropped.
For those unfamiliar it is an emulator that started out just doing the GBA but over the years added those other things (also PS1 PocketStation as it was similar hardware). Its debugger (useful for homebrew authors, ROM hackers, commercial developers, cheat makers and more besides) is one of the best going and its accuracy as an emulator is also right up there.
The hardware documentation it is associated with is also the main reference for most people doing the above http://problemkaputt.de/gbatek.htm
You can find it
http://problemkaputt.de/gba.htm
Main site where several equally potent emulators also exist
http://problemkaputt.de
Seems most of the changelog today concerns some bugfixes for various things (more on the rare side of things but still bugfixes) and the documentation of the 3ds hardware.
For those unfamiliar it is an emulator that started out just doing the GBA but over the years added those other things (also PS1 PocketStation as it was similar hardware). Its debugger (useful for homebrew authors, ROM hackers, commercial developers, cheat makers and more besides) is one of the best going and its accuracy as an emulator is also right up there.
The hardware documentation it is associated with is also the main reference for most people doing the above http://problemkaputt.de/gbatek.htm
You can find it
http://problemkaputt.de/gba.htm
Main site where several equally potent emulators also exist
http://problemkaputt.de
Seems most of the changelog today concerns some bugfixes for various things (more on the rare side of things but still bugfixes) and the documentation of the 3ds hardware.
No$gba Release Notes 25 Apr 2020 - version 3.01 said:- 3ds/help: added info on arm11/arm9 bootrom 3DS Exception Vectors
- 3ds/help: added info on bootrom key generator for AES key slots
- 3ds/help: added more notes/questions on still needed unknown gpu things
- 3ds/help: more gpu notes from 3dbrew (but isn't yet understood what they mean)
- 3ds/help: ntrcard on arm11 side: triggers cdma 01h, and interrupt 44h
- 3ds/help: clarified gamecard insert/pwroff irqs on arm9 and arm11 sides
- 3ds/help: info on starting/stopping arm11 cpu1 and cpu2/3 cores
- 3ds/help: details: pad irq 5Bh, memory enable for 08100000h and 1F000000h
- 3ds/help: added specs for Level 2 Cache (L2C) registers and cache irq 76h
- 3ds/help: added specs for AXI bus matrix registers (mostly readonly)
- 3ds/help: added specs ARM7 aka GBA config registers (and guess on gba footer)
- 3ds/help: added specs for LGYFB gba/nds framebuffer converters (thanks sono)
- 3ds/help: added specs for RGB-to-RGBA converter (L2B) (new3ds mvd related)
- 3ds/help: added specs for YUV-to-RGBA converter (Y2R) (camera related)
- 3ds/help: added many details for CTRCARD registers/seed/protocol
- dsi/help: added SCFG_CARD_xxx_DELAY specs, better cart power on/off sequences
- 3ds/help: added chapter with 3DS Console IDs and ID0/ID1 folder names
- 3ds/help: added mcu reflashing specs via uart cable on tool0 pin
- 3ds/help: renamed mcu looping-queue-stack-nonsense to battery-backed-ram
- 3ds/help: added details on mcu i2c-slave devices (fuel gauge and powerman/tsc)
- 3ds/help: rev-engineered RSA and SHA register details
- 3ds/help: fixed weird IPC_SYNC aka PXI_SYNC description
- 3ds/help: added specs for VFP vector-floating-point opcodes/registers
- 3ds/help: added tsc page 64h/65h/67h/FBh register info (thanks profi200)
- gba/bios: fixed multiboot-upload crash upon too many slaves or too much data
- dsi/debug: debugmsg window displays TSC page number alongsides with TSC index
- a22i/arm: bugfixed shortform for MOV Rd,shift (other than ALU Rd,Rx,shift)
- a22i/float: added data directives .float16/24/32/64/80
- a22i/dis: fixed corelink dma reladdr for loops (unsigned, target=$-offset)
- 3ds/disass: bugfixed RL78 short addr, and "[SFR+1]" for MSBs of SFRs
- 3ds/debug: added RL78 assembler for MCU code (and RL78 opcode list in help)
- 3ds/debug: added assembler/disassembler for VFP floating point opcodes
- 3ds/debug: added assembler/disassembler for CDMA/XDMA corelink dma opcodes