PMON Initialization

Execution starts at 0xbfc00000 (0xa0c00000 on the LR64360). At this address there is a jump to _start (usually at 0xbfc00274).

_start: (pmon/mips.s)

jal cpuInit

This calls getHostType and then sets up the RAM and returns a pointer to the correct cache flush routine, and the CPU type.

jalr s0

Calls the correct flush routine to flush the Dcache. It calls indirect via register s0, which was set by cpuInit.

jal cpdata

Copies the .data section from the PROM to the RAM.

jal clrbss

Clears the .bss section in RAM.

jal copyHandler

Copies the exception handler to the exception vector in RAM.

jal copyHandler

Copies the exception handler to the exception vector in RAM.

jalr s0

Calls the correct flush routine to flush the Dcache. It calls indirect via register s0, which was set by cpuInit.

jalr s0

Calls the correct flush routine to flush the Icache. It calls indirect via register s0, which was set by cpuInit.

jal pmoninit

Calls pmoninit, this is the first piece of C. At this point PMON switches to kseg0 addresses (assuming that PMON was linked at a kseg0 address).

pmoninit() (pmon/main.c)

jal mfc0

Uses mfc0() to read the Status register (C0_SR). This is the first time that RAM is assumed to be working. If RAM is not working, control will not return from this call.

jal hostInit(8)

Initialize the DUART. This calls addDevice, which calls the OP_INIT section of the driver.

jal moninit

Initializes the core Monitor.

jal addCmdRec

Called several times. Adds PMON-specific commands to the Monitor.

jal addEnvRec

Called several times. Adds PMON-specific environment variables to the Monitor.

jal sprintf -- do_cmd

This pair of functions is called three times. They set two environment variables and define the symbol Pmon.

jal addGpRegs

Add the Gp registers to the list of registers.

jal hostInit

Perform additional initialization.

jal printf

Print the first part of the banner.