Nuevo emulador GBA: gpSP (#2)

# Fixed a dynarec bug involving flags generating functions in
contiguous conditional blocks. Fixes music in Super Mario
Advance 2-4.
# Fixed a dynarec bug where Thumb mov imm instructions wouldn't
set flags. Fixes Zelda: Minish Cap, Megaman Battle Network,
probably others. Comes at a slight speed cost.
# Fixed a MIPS dynarec bug where some delay slots might not
get filled rarely, causing chaos. Don't know if it improves
any games.
# Improved self-modifying code detection. Makes Golden Sun,
Golden Sun 2, and Madden 2007 sorta work but excrutiatingly
slowly. Looking for a game-specific workaround for this - if you
want to play these games you'll have to wait for now
# Fixed a bug causing the interrupt disable flag to go down
when SWIs are entered, causing crashes/resets. Fixes
Super Mario Advance 2-4.
# Fixed menu crashing when strings with certain characters are
printed (for instance going to the menu after loading the
BIOS)
# Accidentally forgot to render win0 + win1 + objwin when all
active at the same time, many weeks ago. Added that, should fix
some parts in games that had frozen screens.
# Fixed some issues with gpsp.cfg needing to be present and
corrupting, hopefully. At the very least sanity checks are
performed on the config file.
# Made it so assigning the frameskip button to something besides
triangle actually worked as expected.
# Fixed ability to restart current game if nothing is loaded
(ie, crash)
# Added interrupt on cpsr modification support to the dynarec
(fixes backgrounds in Castlevania: Harmony of Dissonance)
# Added open addressing for ldm/stm instructions (fixes
Super Mario Advance 3)
# Improved cycle accuracy a little. Don't know of anything this
fixes, but games with idle loops will run a little better w/o
idle loop elimination (but should still be added when possible)
# Fixed some bugs causing sound to play sometimes when it shouldn't.
@ Added dead flag elimination for Thumb code. May possibly have
noticeable performance increases (Thumb emited coded size can
have a reduction of 20% or more)
@ Added code generation for divide SWI. May have a small speed
increase in some games.
+ Added analog nub support (special thanks to psp298 for the
code)
+ Added fractional frameskip. Go below 0 to get them. A frameskip
of 1/2 for instance means render 2 out of every 3 frames, 2/3
means render 3 out of every 4 frames, etc. Possibly useful for
games that are not quite fast enough at fs0 but fullspeed at
fs1...

v0.6 - (still beta quality, look out for new bugs)
NOTE: Please include gpsp.cfg with EBOOT.PBP, this shouldn't be necessary but I think it is right now.
# Fixed a nasty bug that shouldn't have made it into the initial release; a lot of games that TECM.. erm.. crash won't anymore. NOTE: This doesn't mean that no game will ever crash, freeze,
otherwise not work.
# Fixed some crashes in the GUI and the ability to "go up" past ms0:/PSP. Made the "go up" button square like it was supposed to be (instead of cross).
+ There's now a menu that you can access, by default press right while holding down triangle for the frameskip bar.
+ Menu option: resize screen aspect ratio, the default is now "scaled 3:2" which makes it look more like a normal GBA. You can use "fullscreen" (what it was like before) or "unscaled 3:2"
(tiny but pixel for pixel like a GBA)
+ Menu option: You can now load new games while the current one is running.
+ Menu option: You can now restart the currently running game.
+ Menu option: Frameskip variation - this defaults to "uniform" whereas it defaulted to "random" last release. Basically, turn it on random if you find that frameskip causes flickering animations to make things disappear. Other than that it will generally look better on uniform.
+ GUI and file loading now have "auto repeat" on the buttons so they're not such a pain to navigate.
+ Menu option: Added support for 128KB flash ROM, some games require it (Pokemon Firered/Leaf Green, Super Mario Advance 4), turn it on before running the game to make sure it works. NOTE: There are some versions of these ROMs that have been hacked to get around their 128KB flash, and may not even work properly at all. Look out for them, these games should save 128KB save files after you set the setting to it, IF they use 128KB flash.
+ Menu option: Added ability to make the .sav files only update when you exit the emulator, use with extreme caution (in other words, it's not a good idea to use something like this in beta quality software if you care about your saves). Does NOT update if you exit through the home button, don't use the home button if you can help it.
+ Zip support thanks to SiberianSTAR. It will load the first file with the extension .gba or .bin that it finds.
+ Menu options are saved to gpsp.cfg. Note that it does not save frameskip options or flash ROM options because these are very per game particular.
+ The emulator will now try to save backup files to somethingmore matching the backup size than a fixed 64KB. @ Loading ROMs and the auto save of the .sav files is MUCH faster now. Thanks for the heads up on how to improve this from pollux!
@ While coding for the screen resize code I found that SDL just wasn't cutting it and had to code for the GU myself. Turns out the new code is faster (but because it is render code anyimprovement will be diminished to nothing as frameskip is increased). Special thanks to Zx-81 for the tips on this one
and for his GU code in the PSPVBA source as an example.
@ Added some games to game_config.txt. Note that not all versions of these ROMs will work with these options, try to use the USA version if possible.

Just a note, be SURE to include the included gpsp.cfg with the EBOOT or things might get messed up. It shouldn't need it but I guess it does for now.

gameplaySP (gpSP for short) is a GBA emulator written completely from scratch. It is still pretty young (only having started a 3 months ago)
and thus rather immature, but it does a decent job of playing a number of games. It is currently very minimalistic, in the sourcecode, presentation, and features. Its number one focus is to deliver a GBA
gaming experience in the most playable way that PSP can manage, with frills being secondary.

Having said that, optimization was the important way in achieving this goal, with overall compatability being a near second. Because of this
some games may not run at the favor of running more games significantly better. Of course, the compatability will improve with time.

Many games will run at their best out of the box, but some games will run very slowly unless idle loops are taken care of. There is a supplied
ROM database, game_config.txt, that gives idle loop targets and other settings that may help a game to run better (or at all) on a per-game basis. Currently (as of the first release) only a very small number of
games are entered. This number should improve dramatically over time.

gpSP currently requires an authentic GBA BIOS image file to run. It will make no effort to run without one present; this file is 16kb and should
be called gba_bios.bin and present in the same location as the EBOOT.PBP file. Please do not ask me where to obtain this, you'll have to look
online or grab it from a GBA. Note that it is not legal to have this file unless you own a GBA, and even then it's rather gray area.

-- Features --

gpSP mostly emulates the core Gameboy Advance system. As of right now it does not emulate any special hardware present on various GBA cartridges.

What it emulates:

GBA CPU: All ARM7TDMI ARM and Thumb mode opcodes except block memory w/ s-bit (probably aren't used in GBA games) Video: Modes 0, 1, 2 almost completely, basic 3-5 support, sprites,
windows/OBJ windows Interrupts: HBlank, VBlank, all timers, all DMA channels, keypad DMA: Immediate, HBlank, VBlank, sound timer triggered
Sound: Both DirectSound channels and all 4 GBC audio channels Input: Basic GBA input delivered through PSP controls Cartridges: Currently supports up to 16MB large ROMs (32MB will not load)
Backup: 32/64kb SRAM, 64kb flash, 512bit/8kb EEPROM

What it lacks:

Video: No mosaic, bitmap modes lack color effects (alpha, fades), there might be some minor inaccuracies in blending...Cycle accuracy: Very cycle innacurate; CPU is effectively very overclocked, meaning games with rampant idle loops will probably run very poorly. DMA transfers effectively happen for free (0 cycle). Please do NOT use gpSP as a first source for developing GBA homebrew,
try No$GBA instead.Backup: 128kb flash is not currently supported.

-- Controls --

The control scheme is very simple and currently can not be changed.

At the ROM selection screen:

Up/down: navigate current selection window.
Left/right: switch between file window and directory window. Circle/start: select current entry.
Square: go one directory up.