Specifications

132 AMD Geode™ GeodeROM Functional Specification
System Services
32087C
12.1.10.3 Subfunction 02h - Write ACCESS.bus Block
Description:
Write a byte of data to an ACCESS.bus device.
Passed:
Returns:
Related Functions:
None.
12.1.10.4 Subfunction 03h - Read NVRAM Data
Description:
Reads data associated with a particular token from NVRAM. The data is right-justified and up to eight bits wide.
GeodeROM is responsible for determining the correct location from which information is read. The caller is responsible
for knowing the format of the data (see Table 12-4 on page 136).
Passed:
Parameter Description
AX BE00h
BX 4E53h (= ‘NS’)
CL Register offset
CH ACCESS.bus address
DL Number of bytes to transfer
DS:SI Pointer to transfer buffer
Parameter Description
CF 0 = Success
1 = Failure
Parameter Description
AX BE03h
BX 4E53h (= ‘NS’)
CX Token
DH Media:
00h = CMOS
01h = System ROM Flash
02h = Serial EEPROM
03h-FFh = Reserved