tm_dmem_boot.s
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/*
* tm_dmem_boot.s: Bootstrap file which loads tm_dmem into rsp dmem memory
* from the standard gload point within ramrom. We always
* load 0x400 bytes for simplicity of implementation.
*/
#include "regdef.h"
#include "asm.h"
#include <R4300.h>
#include <rcp.h>
#include "tinymon.h"
#define DMEM_LOAD_ADDRESS 0x04000000
#define RAMROM_SRC_ADDRESS 0x10002000
#define TINYMON_DMEM_SIZE 0x00000400
LEAF (tm_dmem_boot) # Address = 0xB0000400.
.set noreorder
li t1, SR_BEV|SR_CU0 # Initialize SR
mtc0 t1, C0_SR # Clear Status Register.
.set reorder
# Load the tinymon program from 0x10002000 in ramrom to 0x04000000 in rsp dmem.
# (We use 0xB0002000 and 0xa4000000, since K1 seg guarantees uncached access).
la t0, PHYS_TO_K1(RAMROM_SRC_ADDRESS)
la t1, PHYS_TO_K1(DMEM_LOAD_ADDRESS)
la t2, PHYS_TO_K1(RAMROM_SRC_ADDRESS)
addiu t2, TINYMON_DMEM_SIZE
send:
lw t3, 0(t0) # load monitor from ramrom
sw t3, 0(t1) # store monitor to dmem
/*
jal waitForIdle
*/
addiu t0, 4 # add monitor address
addiu t1, 4 # add dmem adress
bne t0, t2, send
# Jump to the loaded program in dmem.
la t4, PHYS_TO_K1(DMEM_LOAD_ADDRESS)
jr t4
/*
* General purpose subroutine which spins, waiting for the PI controller to
* become idle. Should be called after each RAMROM cartridge interface request
* (for either memory or registers).
*/
.set noreorder
waitForIdle:
lui t4, PI_BASE_REG_UPPER_K1
waitLoop:
lw t5, PI_STATUS_REG_OFFSET(t4)
nop
andi t6, t5, (PI_STATUS_DMA_BUSY | PI_STATUS_IO_BUSY)
bne t6, zero, waitLoop
nop
jr ra
nop
.set reorder
END (tm_dmem_boot)