xref: /OK3568_Linux_fs/u-boot/board/qemu-mips/lowlevel_init.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* Memory sub-system initialization code */
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun#include <config.h>
4*4882a593Smuzhiyun#include <asm/regdef.h>
5*4882a593Smuzhiyun#include <asm/mipsregs.h>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun	.text
8*4882a593Smuzhiyun	.set noreorder
9*4882a593Smuzhiyun	.set mips32
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun	.globl	lowlevel_init
12*4882a593Smuzhiyunlowlevel_init:
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun	/*
15*4882a593Smuzhiyun	 * Step 2) Establish Status Register
16*4882a593Smuzhiyun	 * (set BEV, clear ERL, clear EXL, clear IE)
17*4882a593Smuzhiyun	 */
18*4882a593Smuzhiyun	li	t1, 0x00400000
19*4882a593Smuzhiyun	mtc0	t1, CP0_STATUS
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun	/*
22*4882a593Smuzhiyun	 * Step 3) Establish CP0 Config0
23*4882a593Smuzhiyun	 * (set K0=3)
24*4882a593Smuzhiyun	 */
25*4882a593Smuzhiyun	li	t1, 0x00000003
26*4882a593Smuzhiyun	mtc0	t1, CP0_CONFIG
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun	/*
29*4882a593Smuzhiyun	 * Step 7) Establish Cause
30*4882a593Smuzhiyun	 * (set IV bit)
31*4882a593Smuzhiyun	 */
32*4882a593Smuzhiyun	li	t1, 0x00800000
33*4882a593Smuzhiyun	mtc0	t1, CP0_CAUSE
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun	/* Establish Wired (and Random) */
36*4882a593Smuzhiyun	mtc0	zero, CP0_WIRED
37*4882a593Smuzhiyun	nop
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun	jr	ra
40*4882a593Smuzhiyun	nop
41