1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
#include "ultra64/asm.h"
#include "ultra64/regdef.h"
#include "boot.h"
.text
#if defined(NON_MATCHING) || defined(__sgi)
/* Non-matching builds or IDO */
#define PAD_TO 0x60
#define LA(reg, sym) la reg, sym
#define BOOT_STACK_TOP sBootThreadStack + BOOT_STACK_SIZE
#else
/* EGCS */
#define PAD_TO 0x50
#define LA(reg, sym) \
lui reg, %lo(sym##_HI); \
ori reg, %lo(sym)
#endif
#if !defined(AVOID_UB)
/* Old assembler workarounds: The makerom tool in the N64 SDK was given the bss segment size as a const
* literal, and since this literal was < 0x10000 it was loaded in one instruction. We don't have access
* to the bss segment size until we link everything so we cannot do the same thing. Instead we must load
* only the lower 16 bits of the bss size for matching.
* When AVOID_UB is enabled, don't do this and instead load the full symbol value, otherwise not all of
* bss may be cleared. */
#if defined(__sgi)
#define LOAD_BSS_SIZE(reg) li reg, %half(_bootSegmentBssSize)
#else
#define LOAD_BSS_SIZE(reg) ori reg, zero, %lo(_bootSegmentBssSize)
#endif
#else
#define LOAD_BSS_SIZE(reg) LA(reg, _bootSegmentBssSize)
#endif
LEAF(entrypoint)
/* Clear boot segment .bss */
LA( t0, _bootSegmentBssStart)
LOAD_BSS_SIZE(t1)
.clear_bss:
sw zero, 0(t0)
sw zero, 4(t0)
addi t0, t0, 8
addi t1, t1, -8
bnez t1, .clear_bss
/* Set up stack and enter program code */
LA( sp, BOOT_STACK_TOP)
LA( t2, bootproc)
jr t2
END(entrypoint)
#ifdef __sgi
/* IDO can't take absolute differences of symbols so the size of the above is hardcoded */
.space PAD_TO - 0x34
#else
/* Pad to a total size taking into account the size of the above */
.space PAD_TO - (. - entrypoint)
#endif
|
