Specifications
DIGITAL-LOGIC AG Geode LX800 Manual V1.1C
Driver, Software & BIOS Information
49
7.4. BIOS Diagnostics – Post Codes
This is the GeodeRom port 80 flow for a cold boot on a gx system. There are some additional codes on a
scx2xx system. This shows what functions generate which port 80 code. The first column of codes is gener-
ated by xpresrom.asm; the second column is the function which is run after the post code and any additional
post codes generated by that function.
Digital-Logic LX800 Post Codes
Info: Informational code only
Error: Error code. The system halts
Info/Error: Informational code but the system can halt.
Checkpoint Description Type
00h Initialize CS5536 specific registers Info
02h Initialize some cpu registers Info
03h Initialize ES and FS as Big Real Mode segments Info
05h Test CPUID instruction Info
06h Setup DRAM Memory controller
- Detect installed DRAM modules
- Detect memory size
- Detect memory timing
=> See Post 7xh
Info
07h Set up a stack for further post tests.
=> See Post 90h, 9Eh, 9Fh
Info
08h Perform memory test
=> See Post 0Bxh
Info
09h Copy ROM (F000:0 - F000:FFFF) into SDRAM (F000:0 - F000:FFFF)
and disable write access to shadow memory.
Info
0Bh Initialize L1 and L2 cache
=> See Post 0CEh
Info
0Ch Core Logic initialization: Host bridge
- Setup GLPCI registers
- Enable Clock Gating
- Setup AES engine
- Apply CPU bugfixes
=> See Post 0E8h
Info
0Dh Platform specific chipset Init Info
0Eh Initialize Super I/O Info
0Fh PC/AT Compatibility stuff
- Initialize DMA controller to AT compatible mode
- Clear the first 640kB of memory (to make DOS happy)
- Clear 2
nd
MB of memory (to make DOS happy)
Info
10h Set up software interrupt vectors
- Setup interrupt vectors
- Program interrupt controller for PC usage
- Initialize Timer
Info
11h store how much memory is available to the OS Info
12h Decompress ROM images and initialize them
- Soft A20
- Power Management
- Soft VGA
- Virtual Audio
- SMM system
=> See post 0Dxh
Info
13h Check for PLL reset and set PLLs if not done already
=> See port 0Axh
Info
14h Wakeup the keyboard controller Info
Checkpoint Description Type