I have put a temporary version check into loader/sx280hs/main.c, that will need to be modified too as it only expects 102b.
( ( *(int*)0xfc142898 != 0x4232302e ) && ( *(int*)0xfc142898 != 0x4332302e ) )
You may want to tryhttp://chdk.wikia.com/wiki/User:Srsa_4c/GPL:disassemblev7.plon the 102b and 102c dumps, and use the resulting (not perfect) disassembly listings to locate the needed functions and firmware variable addresses for the 102c firmware.Once this step is complete, all assembly parts found in platform/sx280hs/sub/102b/ files (such as boot.c, capt_seq.c) will have to be corrected to use the 102c addresses. Of course, you'll need to work on the platform/sx280hs/sub/102c directory (start with a copy of the 102b files).
DEF(active_raw_buffer ,0x0000a08c) // Found @0xfc13fa6c, 0xffffffff when uninited...DEF(physw_sleep_delay ,0x00008330) // Found @0xfc0601f6DEF(FlashParamsTable ,0xfc7313a0) // 0xfc730610 -> 0xfc7313a0
I've changed the version check conditional to get around it, but haven't tested it yet.Code: [Select]( ( *(int*)0xfc142898 != 0x4232302e ) && ( *(int*)0xfc142898 != 0x4332302e ) )
Started working on the sub/102c/stubs_min.S, but hit a few issues:Code: [Select]DEF(active_raw_buffer ,0x0000a08c) // Found @0xfc13fa6c, 0xffffffff when uninited...DEF(physw_sleep_delay ,0x00008330) // Found @0xfc0601f6DEF(FlashParamsTable ,0xfc7313a0) // 0xfc730610 -> 0xfc7313a0I can't make sense of what's going on at those addresses in the 102b dump...
loc_fc13fa6c: ; 2 refsfc13fa6c: b510 push {r4, lr}fc13fa6e: 4cdf ldr r4, [pc, #892] ; 0xfc13fdec: (0000a080) ; ****** base addressfc13fa70: 69a0 ldr r0, [r4, #24]fc13fa72: b928 cbnz r0, loc_fc13fa80fc13fa74: 2000 movs r0, #0fc13fa76: f240 123c movw r2, #316 ; 0x13cfc13fa7a: a1d8 add r1, pc, #864 ; 0xfc13fddc: (6d497353) *"SsImgProcBuf.c"fc13fa7c: f112 e94a blx loc_fc251d14 ; <DebugAssert>loc_fc13fa80:fc13fa80: 69a0 ldr r0, [r4, #24]fc13fa82: f112 e838 blx loc_fc251af4fc13fa86: 07c0 lsls r0, r0, #31fc13fa88: d005 beq.n loc_fc13fa96fc13fa8a: 2000 movs r0, #0fc13fa8c: f240 1242 movw r2, #322 ; 0x142fc13fa90: a1d2 add r1, pc, #840 ; 0xfc13fddc: (6d497353) *"SsImgProcBuf.c"fc13fa92: f112 e940 blx loc_fc251d14 ; <DebugAssert>loc_fc13fa96:fc13fa96: 6860 ldr r0, [r4, #4]fc13fa98: f02d fca3 bl loc_fc16d3e2fc13fa9c: 68e1 ldr r1, [r4, #12] ; ****** +0xc offsetfc13fa9e: 1e40 subs r0, r0, #1fc13faa0: 4288 cmp r0, r1fc13faa2: d102 bne.n loc_fc13faaafc13faa4: 2000 movs r0, #0fc13faa6: 60e0 str r0, [r4, #12]fc13faa8: bd10 pop {r4, pc}
NSTUB(task_PhySw, 0xfc0601f4):fc0601f4: b510 push {r4, lr}fc0601f6: 4c16 ldr r4, [pc, #88] ; 0xfc060250: (00008328) **** base addressfc0601f8: e008 b.n loc_fc06020cloc_fc0601fa:fc0601fa: 68a0 ldr r0, [r4, #8] ; **** offsetfc0601fc: f1f1 ed5a blx loc_fc251cb4 ; <SleepTask>
fc0601f4: b510 push {r4, lr}fc0601f6: 4c16 ldr r4, [pc, #88] ; 0xfc060250: (00008328) fc0601f8: e008 b.n loc_fc06020cloc_fc0601fa:fc0601fa: 68a0 ldr r0, [r4, #8]fc0601fc: f1f1 ed9e blx loc_fc251d3c ; SleepTask
Quote from: codertux on 17 / June / 2014, 19:51:17I bought a sx270hs a few days ago. I'm very interested in the port, but it seems Canon shipped it with firmware version 102c (1.0.2.0) so I'm unable to test this build. Is it possible to downgrade somehow?There is no way to downgrade. In fact, Canon seldom even allows you to upgrade when they produce a new rev of their firmware.However, it's not all bad news. Sometimes two firmware versions can use the same CHDK port - but almost always only if they have sequential revision numbers (like yours). And if not, it's pretty easy these days for someone to produce a new port once the first one for a camera model is finished.What is needed is a firmware dump. Either to check and see if the versions are compatible or to be used in producing a new port. If you feel up to taking the first step, here's the instructions : http://chdk.wikia.com/wiki/Canon_Basic/Scripts/Dumper . Before you start though, you might want to wait and see if srsa_4c posts any caveats.
I bought a sx270hs a few days ago. I'm very interested in the port, but it seems Canon shipped it with firmware version 102c (1.0.2.0) so I'm unable to test this build. Is it possible to downgrade somehow?
Hello,Is there any way I can downgrade my firmware from 102C to 102B, I need CHDK on my SX280HS for a project urgently. Also I will be happy to test / upload dumps etc. Hoping CHDK will be released soon for 102C firmware.
I have a sx270hs with firmware revision 102c, a firmware dump from your camera would help us confirm they are indeed using the same firmware.
We don't actually need additional firmware dumps once we have the first one for each firmware version.
Canon PowerShot SX280 HSP-ID:325F NT DFirmware Ver GM1.02C(1.0.2.0)Adj Ver.012.010Serial No. 712054xxxxxxDump file:https://www.sendspace.com/file/amzcaz Hope its useful.
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