Merge pull request #2 from amnemonic/main

Added description of first mod

k5_v2.01.19_mod.md

@@ -0,0 +1,62 @@
+## Files info
+Original MD5 `4102238f8f9d336409e2c2f1ba36c96b` <br>
+Modded MD5: `5125458a4231f67c237cb1ce71af9159`
+
+
+## Changes
+#### 1) At address `@0x1af4`: `00 87 93 03` => `40 ff 10 05`
+This is part of function `sub_1ABC` in which frequency is compared with value of 60000000 / 0x03938700 which is internal representation of 600MHz.
+
+```asm
+ROM:00001ABC                   ; int __fastcall sub_1ABC()
+...
+ROM:00001AE2 04 4A                             LDR     R2, =60000000   ;indirect addresing from [1AF4]
+ROM:00001AE4 91 42                             CMP     R1, R2          ;compare if R1 (entered frequency is higher than 600MHz)
+ROM:00001AE6 00 DD                             BLE     loc_1AEA        ;if no then skip next command
+ROM:00001AE8 11 46                             MOV     R1, R2          ;set current frequency to max (600MHz)
+ROM:00001AEA                   loc_1AEA                                ; CODE XREF: sub_1ABC+24↑j
+ROM:00001AEA 81 60                             STR     R1, [R0,#8]
+ROM:00001AEC 10 BD                             POP     {R4,PC}
+ROM:00001AEC                   ; End of function sub_1ABC
+...
+ROM:00001AF0 40 4B 4C 00       dword_1AF0      DCD 5000000            
+ROM:00001AF4 00 87 93 03       dword_1AF4      DCD 60000000            ;*** PATCH HERE from 60000000 to 85000000 (0x03938700 to 0x0510FF40)
+```
+
+
+
+
+
+#### 2) At address `0xa224`: `ff` => `07`
+When in _Common setting_ you set option _Power on display mode_ to _Full screen_ then you will be welcomed with LCD screen wiht all pixels active. This is done by function at address `@BE60`. Basically it is done with filling display memory with 0xFF. Setting it argument of this function to `7` displays bars like in binary representation `0b00000111`. It could be fun to patch this with `0x55` then it should effect in thinner stripes :)
+
+```asm
+ROM:0000A224 FF 20                             MOVS    R0, #0xFF ; *** PATC HERE -> parameter for function sub_BE60 changed from 0xFF to 0x07
+ROM:0000A226 01 F0 1B FE                       BL      sub_BE60
+```
+
+
+
+
+### 3) at address `0xeae8`: `80 cb a4 00` => `40 77 1b 00` and 
+### 4) at address `0xeb18`: `00 87 93 03` => `40 ff 10 05`
+At latter parts of firmware file, near the end we have some nice looking arrays. Both are used in function at `@188C` (TODO: describe what that function does). 
+
+```asm
+ROM:0000EAE4 40 4B 4C 00       dword_EAE4      DCD 5000000
+ROM:0000EAE8 80 CB A4 00                       DCD 10800000   ; *** PATCH HERE: from 108Mhz to 18Mhz (0x00A4CB80 to 0x001B7740)
+ROM:0000EAEC 00 85 CF 00                       DCD 13600000
+ROM:0000EAF0 C0 80 09 01                       DCD 17400000
+ROM:0000EAF4 C0 0E 16 02                       DCD 35000000
+ROM:0000EAF8 00 5A 62 02                       DCD 40000000
+ROM:0000EAFC C0 29 CD 02                       DCD 47000000
+ROM:0000EB00 80 F7 73 00       dword_EB00      DCD 7600000
+
+ROM:0000EB04 F6 84 CF 00                       DCD 13599990
+ROM:0000EB08 B6 80 09 01                       DCD 17399990
+ROM:0000EB0C B6 0E 16 02                       DCD 34999990
+ROM:0000EB10 F6 59 62 02                       DCD 39999990
+ROM:0000EB14 B6 29 CD 02                       DCD 46999990
+ROM:0000EB18 00 87 93 03                       DCD 60000000  ; *** PATCH HERE: from 600Mhz to 850Mhz (0x03938700 to 0x0510FF40)
+```
+