Please make porting easier by completing and adding this file to docs

[mfp20]

// all options available with brief comments and some sort of categorization
// Note: it's a work in progress to make a porting helper file to keep in docs/

//--------------------------------------------------------------------+
// general options
//--------------------------------------------------------------------+
// clock rate
#define TICKSPERSEC 1000
// low memory address for applications (should be 0x100 to run standard binaries)
#define PROGBASE 0x100
// In most cases PROGBASE is 0 and PROGLOAD is 0x100. In all cases, PROGBASE<=PROGLOAD.
#define PROGLOAD 0x100
// first byte above main memory, usually the start of the udata area and common memory
#define PROGTOP
// pointer to a null-terminated command line passed from the loader/firmware. Set to NULL if none
#define CMDLINE NULL
// Enables kernel32.h on 32bits ports
#define CONFIG_32BIT
// Enables process accounting
#define CONFIG_ACCT
// Inlined irq handling
#define CONFIG_INLINE_IRQ
//
#define CONFIG_LEVEL_0
//
#define CONFIG_LEVEL_2
// no timer interrupt available
#define CONFIG_NO_CLOCK
//
#define CONFIG_PLATFORM_SUSPEND
// Profil syscall support (not yet complete)
#define CONFIG_PROFIL
// Use soft irqs
#define CONFIG_SOFT_IRQ
//
#define CONFIG_UDATA_TEXTTOP

//--------------------------------------------------------------------+
// memory banks
//--------------------------------------------------------------------+
// Selects support for four flexible 16K bank registers
#define CONFIG_BANK16
//
#define CONFIG_BANK16FC
//
#define CONFIG_BANK16_LOW
// Selects support for two flexible 32K bank registers
#define CONFIG_BANK32
//
#define CONFIG_BANK_65C816
//
#define CONFIG_BANK8
//
#define CONFIG_BANK_8086
//
#define CONFIG_BANKED
// Selects support for lower memory bank selector / fixed common at the top
#define CONFIG_BANK_FIXED
// Selects a system where memory is managed linearly with base/limit pairs or similar and a common
#define CONFIG_BANK_LINEAR
//
#define CONFIG_BANKS
// 32K common, ldir copying to use for 48K apps
#define CONFIG_COMMON_COPY
//
#define CONFIG_HAS_LOW_PAGE
//
#define CONFIG_LOW_PAGE
//
#define CONFIG_SUPERVISOR_SPACE
//
#define CONFIG_VIDMAP8

//--------------------------------------------------------------------+
// block devices
//--------------------------------------------------------------------+
// number of buffers for disk cache (each a bit of 512 bytes)
#define NBUFS 0
// number of things that can be mounted at a time
#define NMOUNTS 0
//
#define CONFIG_FLOPPY
#define CONFIG_FLOPPY_NOHD
//
#define CONFIG_IDE
#define CONFIG_IDE_BSWAP
#define IDE_DRIVE_COUNT 0
//
#define CONFIG_SCSI
// Enable SD card code
#define CONFIG_SD
#define SD_DRIVE_COUNT 0 // Number of SD cards
//
#define CONFIG_RAMDISK
// On systems with 32bit blkno_t we support larger block sizes (not supported, yet)
#define CONFIG_BIG_FS
//
#define CONFIG_BLKBUF_EXTERNAL
//
#define CONFIG_BLKBUF_HELPERS
//
#define CONFIG_BLOCK_SLEEP
//
#define CONFIG_GPT
// Enable to make ^Z dump the inode table for debug
#define CONFIG_IDUMP
// Tells dev/mbr.c where to find the MBR
#define CONFIG_MBR_OFFSET
// Trim disk blocks when no longer used
#define CONFIG_TRIM
//
#define CONFIG_LARGE_IO_DIRECT

//--------------------------------------------------------------------+
// ram and swap
//--------------------------------------------------------------------+
// lowest address that will be swapped
#define SWAPBASE
// highest address that will be swapped
#define SWAPTOP
// special use (set to 0)
#define UDATA_BLOCKS 0
//
#define UDATA_SWAPSIZE
// number of disk blocks needed to hold all the swap for one process
#define SWAP_SIZE
// largest number of SWAP_SIZE chunks that will be used
#define MAX_SWAPS
// brk() calls pagemap_realloc() to get more memory
#define CONFIG_BRK_CALLS_REALLOC
// Enables buddy allocator
#define CONFIG_BUDDY_MALLOC
// Runtime stacks arguments backwards
#define CONFIG_CALL_R2L
//
#define CONFIG_CUSTOM_VALADDR
//
#define CONFIG_DYNAMIC_BUFPOOL
// Memory allocation on systems with a single flat address space and no bank or limit registers
#define CONFIG_FLAT
//
#define CONFIG_INDIRECT_QUEUES
// swap: multiple processes in memory at once
#define CONFIG_MULTI
// pure swap config: always give the parent a chance to get to waitpid()
#define CONFIG_PARENT_FIRST
// Enable dynamic swap
#define CONFIG_PLATFORM_SWAPCTL
// No fast swap device, limited memory
#define CONFIG_SINGLETASK
//
#define CONFIG_SPLIT_UDATA
//
#define CONFIG_STACKSIZE
//
#define CONFIG_SWAP
// Selects NO user banking
#define CONFIG_SWAP_ONLY
// Tells the kernel to use the standard C helpers for user memory copying
#define CONFIG_USERMEM_C
//
#define CONFIG_USERMEM_DIRECT
//
#define CONFIG_VMMU
// Search for the first swap partition on MBR partitioned disks
#define CONFIG_DYNAMIC_SWAP

//--------------------------------------------------------------------+
// tty, gfx
//--------------------------------------------------------------------+
// the device you will use as your 'console' at boot time. 513 is the first tty, 514 the second etc
#define BOOT_TTY 513
// number of tty devices (video consoles/serial)
#define NUM_DEV_TTY 0
// device init will use as input/output (usually BOOT_TTY)
#define TTYDEV 0
//
#define CONFIG_VT
//
#define CONFIG_VT_MULTI
//
#define CONFIG_VT_SIMPLE
// Includes fonts
#define CONFIG_FONT_4X6
#define CONFIG_FONT_4x8
#define CONFIG_FONT6X8
#define CONFIG_FONT8X8
#define CONFIG_FONT_8X8_EXP2
#define CONFIG_FONT8X8SMALL
// Enable to make ^A drop back into the monitor
#define CONFIG_MONITOR
//
#define CONFIG_PTY_DEV
//
#define CONFIG_UNIKEY

//--------------------------------------------------------------------+
// RTC
//--------------------------------------------------------------------+
// Enables platform_rtc_secs()
#define CONFIG_RTC
// Enables platform_rtc_read() and platform_rtc_write()
#define CONFIG_RTC_EXTENDED
// Enables platform_rtc_ioctl()
#define CONFIG_RTC_FULL
// Number of deciseconds between platform_rtc_secs() calls
#define CONFIG_RTC_INTERVAL
//
#define CONFIG_RTC_REG_NVRAM
//
#define CONFIG_RTC_RP5C01_NVRAM

//--------------------------------------------------------------------+
// Network
//--------------------------------------------------------------------+
//
#define CONFIG_NC200
//
#define CONFIG_NET
//
#define CONFIG_NET_NATIVE
//
#define CONFIG_NET_WIZNET
//
#define CONFIG_NET_WIZNET5300
//
#define CONFIG_WIZNET_INDIRECT

//--------------------------------------------------------------------+
// misc devices
//--------------------------------------------------------------------+
// Enables audio core support
#define CONFIG_AUDIO
//
#define CONFIG_DEV_GPIO
//
#define CONFIG_DEV_I2C
//
#define CONFIG_DEV_MEM
//
#define CONFIG_DEV_PLATFORM
//
#define CONFIG_DEV_PTY
//
#define CONFIG_INPUT
//
#define CONFIG_INPUT_GRABMAX
// Enables generic printer interface
#define CONFIG_LP_GENERIC

//--------------------------------------------------------------------+
// Platform specific: 6502-based
//--------------------------------------------------------------------+
//
#define CONFIG_RAMWORKS

//--------------------------------------------------------------------+
// Platform specific: 6809-based
//--------------------------------------------------------------------+
//
#define CONFIG_COCOIDE
//
#define CONFIG_COCO_KBD
//
#define CONFIG_COCOSDC
//
#define CONFIG_COCOSDFPGA
//
#define CONFIG_COCOSDNANO

//--------------------------------------------------------------------+
// Platform specific: 8086-based
//--------------------------------------------------------------------+
//
#define CONFIG_EMM_BIOS
//
#define CONFIG_KBD_XT
//
#define CONFIG_KEYMAP_DE
//
#define CONFIG_KEYMAP_SE
//
#define CONFIG_IBMPC_EMM

//--------------------------------------------------------------------+
// Platform specific: PDP11
//--------------------------------------------------------------------+
//
#define CONFIG_PDP11_04

//--------------------------------------------------------------------+
// Platform specific: Z80-based
//--------------------------------------------------------------------+
// floppy disk interface
#define CONFIG_BETADISK
// Enables FDC765 floppy disk controller
#define CONFIG_FDC765_MULTISECTOR
// tty, the video is directly mapped
#define CONFIG_GFXBASE
//
#define CONFIG_MULTI_IDE
// P112 port: floppy support
#define CONFIG_P112_FLOPPY
//
#define CONFIG_PPIDE
//
#define CONFIG_PPP
//
#define CONFIG_PROPIO2
//
#define CONFIG_RC2014_CF
//
#define CONFIG_RC2014_FLOPPY
//
#define CONFIG_RC2014_NET
//
#define CONFIG_RC2014_PPIDE
//
#define CONFIG_RC2014_SD
//
#define CONFIG_RC2014_VFD
// tty, timex modes are available
#define CONFIG_TIMEX
//
#define CONFIG_VFD_TERM

//--------------------------------------------------------------------+
// Delete? Don't exist in code (config.h only). 
//--------------------------------------------------------------------+
#define CONFIG_CPM_EMU
#define CONFIG_LEGACY_EXEC
#define CONFIG_PAGE_SIZE    16

[EtchedPixels]

I don't really think it helps - the useful bits need to be in the docs proper not in some scraped file