For the 2.0.0 release:
* bopti:     remove image_t, leaving only bopti_image_t
* project:   remove the compat branch
* gray:      remove g*() functions

Crucial, missing things.
! core:      the four basic memory functions (with automated tests)
! core:      use gint_switch() to handle TLB misses
! core:      return to menu on fxcg50
! syscalls:  fxcg50 BFile calls

Issues.
* #3         make drawing functions parameterized
* #5         add decent random number generation (TinyMT)
* #8         support fx-CG Manager
* #10        support fx-CG 20

Complementary elements on existing code.
* gray:      double-buffer gray settings and unify d* with g*
* display:   deprecate image_t and rename it bopti_image_t
* topti:     support unicode fonts
* gray:      find good values for more models than the Graph 35+E II
* dma:       maybe relax the 4-byte size constraint for dma_memset()
* dma:       fx9860g support (need to switch it on and update the Makefile)
* core:      try to leave add-in without reset in case of panic
* hardware:  fill in the HWMEM_FITTLB flag
* keyboard:  think of extended functions
* cpg:       spread spectrum on fxcg50
* display:   use more of topti's assembler in drect()
* core:      use cmp/str for memchr()
* r61524:    brightness control and clean the file
* t6k11:     check if dupdate() can be done by the DMA

Keep in mind.
* build:     make the build system simpler (two targets are enough by default)
* core:      run destructors when a task-switch results in leaving the app
* core:      invoke main menu instead of returning after main() ends
* prizm:     don't hardcode stack address in fxcg50.ld
* prizm:     detect P1 static RAM (stack) in TLB
* core rtc:  use qdiv10 to massively improve division performance
* setjmp:    more registers may need to be saved
* core:      free heap when a task-switch results in leaving the app
* core:      save and restore interrupt masks
* timer:     make sure ETMU interrupts are disabled in ctx_restore()
* core:      document the SH7305 PFC in <gint/mpu/pfc.h>

Future directions.
* A complete file system abstraction
* Integrate overclock management
* Audio playback using Martin Poupe's method
* Serial communication [SCIF] [SCIFA]
* USB communication [USB]
* Make fx9860g projects work out of the box on fxcg50