I will make a port for sx600 but you have to tell me what firmware version you have and you have to be prepared for a few failed attempts before we get a usable port.
I don't have a camera, so you'll have to do all the testing yourself. If you're ready to do it, let me know, without the possibility of testing, there's no point in trying to make a new port.
https://chdk.fandom.com/wiki/FAQ#Q._How_can_I_get_the_original_firmware_version_number_of_my_camera.3F
I extracted the firmware information using the Exiftool:
Macro Mode : Normal
Self Timer : Off
Quality : Superfine
Canon Flash Mode : Off
Continuous Drive : Single
Focus Mode : Single
Record Mode : JPEG
Canon Image Size : Large
Easy Mode : Manual
Digital Zoom : None
Contrast : Normal
Saturation : Normal
Sharpness : 0
Camera ISO : Auto
Metering Mode : Evaluative
Focus Range : Auto
AF Point : Manual AF point selection
Canon Exposure Mode : Program AE
Lens Type : n/a
Max Focal Length : 81 mm
Min Focal Length : 4.5 mm
Focal Units : 100/mm
Max Aperture : 5.6
Min Aperture : 16
Flash Bits : (none)
Focus Continuous : Single
AE Setting : Normal AE
Image Stabilization : On (2)
Zoom Source Width : 4608
Zoom Target Width : 4608
Spot Metering Mode : Center
Manual Flash Output : n/a
Auto ISO : 53
Base ISO : 200
Measured EV : 15.00
Target Aperture : 5.6
Target Exposure Time : 1/501
Exposure Compensation : 0
White Balance : Auto
Slow Shutter : Off
Shot Number In Continuous Burst : 0
Optical Zoom Code : 48
Flash Guide Number : 0
Flash Exposure Compensation : 0
Auto Exposure Bracketing : Off
AEB Bracket Value : 0
Control Mode : Camera Local Control
Focus Distance Upper : 6.76 m
Focus Distance Lower : 0 m
Bulb Duration : 0
Camera Type : Compact
Auto Rotate : None
ND Filter : Off
Self Timer 2 : 0
Flash Output : 0
Canon Image Type : IMG:PowerShot SX600 HS JPEG
Canon Firmware Version : Firmware Version 1.00
File Number : 102-0117
Camera Temperature : 29 C
Canon Model ID : PowerShot SX600 HS
Thumbnail Image Valid Area : 0 0 0 0
Date Stamp Mode : Off
My Color Mode : Off
Firmware Revision : 1.00 rev 6.00
Categories : (none)
AF Area Mode : Single-point AF
Num AF Points : 9
Valid AF Points : 1
Canon Image Width : 4608
Canon Image Height : 3456
AF Image Width : 4608
AF Image Height : 3456
AF Area Widths : 461 0 0 0 0 0 0 0 0
AF Area Heights : 346 0 0 0 0 0 0 0 0
AF Area X Positions : 0 0 0 0 0 0 0 0 0
AF Area Y Positions : 0 0 0 0 0 0 0 0 0
AF Points In Focus : 0
Primary AF Point : 0
Intelligent Contrast : On (0x19)
Image Unique ID : a85d855fbaf7ffea48e9488cf9030310
Faces Detected : 0
Time Zone : -08:00
Time Zone City : (not set)
Daylight Savings : Off
Aspect Ratio : 4:3
Cropped Image Width : 4608
Cropped Image Height : 3456
Cropped Image Left : 0
Cropped Image Top : 0
VRD Offset : 0
According to Canon's website, there's no other firmware version for this camera model.
