Difference between revisions of "Talk:S5L8720 (Hardware)"

From The iPhone Wiki
Jump to: navigation, search
(New page: ==Weird Registers (Code Snippet)== Here is the behavior of the weird registers I mentioned on the main article. Note that it does it to those four registers in vic0 and vic1, keep that in ...)
 
Line 31: Line 31:
   
 
PS: This is from the [[VROM (S5L8720)|S5L8720]] SecureROM, in case you were wondering about the weird load address.
 
PS: This is from the [[VROM (S5L8720)|S5L8720]] SecureROM, in case you were wondering about the weird load address.
  +
  +
----
  +
  +
Chronic, those registers aren't any great cosmic mystery, they're the peripheral ID for the vic. Way back when, iBoot checked that against the ID for a PL192, which is probably why that old code is still there. The controller probably is a PL192, for that matter. Whatever data sheet you pulled all this off should have had this information.
  +
  +
Also, everything on this page is unsourced. How do you know any of this? Do you have a data sheet for s5l8920? Did you interview a Samsung or Apple engineer? Did you write test implementations to verify the stuff on this page? I know from experience that there might be a few registers corresponding between the actual hardware and some data sheet you find for a related component, but often there's no 100% match. Please provide a reference for every register you mention. If you're not sure about some but believe the device has the same registers as a data sheet you have, cite the data sheet and your reasons for thinking that. Otherwise, this page will be misleading for anyone attempting to use the data. Thanks. --[[User:Planetbeing|Planetbeing]] 15:56, 16 February 2009 (UTC)

Revision as of 15:56, 16 February 2009

Weird Registers (Code Snippet)

Here is the behavior of the weird registers I mentioned on the main article. Note that it does it to those four registers in vic0 and vic1, keep that in mind so you don't think that there are 8 of these weird registers:

ROM:00004C84                 VectorInterruptController_Init          ; CODE XREF: Interrupts_Init+92�p
ROM:00004C84
ROM:00004C84                 var_8           = -8
ROM:00004C84
ROM:00004C84 000 90 B5                       PUSH    {R4,R7,LR}
ROM:00004C86 00C 1B 4B                       LDR     R3, =dword_38E00FE0
ROM:00004C88 00C 01 22                       MOVS    R2, #1
ROM:00004C8A 00C 52 42                       NEGS    R2, R2
ROM:00004C8C 00C 1B 68                       LDR     R3, [R3]
ROM:00004C8E 00C 1A 4B                       LDR     R3, =dword_38E00FE4
ROM:00004C90 00C 1A 48                       LDR     R0, =Vector_Interrupt_Address_Table
ROM:00004C92 00C 01 AF                       ADD     R7, SP, #0xC+var_8
ROM:00004C94 00C 1B 68                       LDR     R3, [R3]
ROM:00004C96 00C 1A 4B                       LDR     R3, =dword_38E00FE8
ROM:00004C98 00C 00 21                       MOVS    R1, #0
ROM:00004C9A 00C 1B 68                       LDR     R3, [R3]
ROM:00004C9C 00C 19 4B                       LDR     R3, =dword_38E00FEC
ROM:00004C9E 00C 1B 68                       LDR     R3, [R3]
ROM:00004CA0 00C 19 4B                       LDR     R3, =unk_38E01FE0
ROM:00004CA2 00C 1B 68                       LDR     R3, [R3]
ROM:00004CA4 00C 19 4B                       LDR     R3, =unk_38E01FE4
ROM:00004CA6 00C 1B 68                       LDR     R3, [R3]
ROM:00004CA8 00C 19 4B                       LDR     R3, =unk_38E01FE8
ROM:00004CAA 00C 1B 68                       LDR     R3, [R3]
ROM:00004CAC 00C 19 4B                       LDR     R3, =unk_38E01FEC
ROM:00004CAE 00C 1B 68                       LDR     R3, [R3]

PS: This is from the S5L8720 SecureROM, in case you were wondering about the weird load address.


Chronic, those registers aren't any great cosmic mystery, they're the peripheral ID for the vic. Way back when, iBoot checked that against the ID for a PL192, which is probably why that old code is still there. The controller probably is a PL192, for that matter. Whatever data sheet you pulled all this off should have had this information.

Also, everything on this page is unsourced. How do you know any of this? Do you have a data sheet for s5l8920? Did you interview a Samsung or Apple engineer? Did you write test implementations to verify the stuff on this page? I know from experience that there might be a few registers corresponding between the actual hardware and some data sheet you find for a related component, but often there's no 100% match. Please provide a reference for every register you mention. If you're not sure about some but believe the device has the same registers as a data sheet you have, cite the data sheet and your reasons for thinking that. Otherwise, this page will be misleading for anyone attempting to use the data. Thanks. --Planetbeing 15:56, 16 February 2009 (UTC)