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
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
// SPDX-License-Identifier: GPL-2.0+
/**
* Copyright (c) 2017 Google, Inc
*/
#include <common.h>
#include <hang.h>
#include <asm/arch-rockchip/bootrom.h>
#include <asm/arch-rockchip/boot_mode.h>
#include <asm/io.h>
#include <asm/setjmp.h>
#include <asm/system.h>
/*
* Force the jmp_buf to the data-section, as .bss will not be valid
* when save_boot_params is invoked.
*/
static jmp_buf brom_ctx __section(".data");
static void _back_to_bootrom(enum rockchip_bootrom_cmd brom_cmd)
{
longjmp(brom_ctx, brom_cmd);
}
void back_to_bootrom(enum rockchip_bootrom_cmd brom_cmd)
{
#if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT)
puts("Returning to boot ROM...\n");
#endif
_back_to_bootrom(brom_cmd);
}
/*
* we back to bootrom download mode if get a
* BOOT_BROM_DOWNLOAD flag in boot mode register
*
* note: the boot mode register is configured by
* application(next stage bootloader, kernel, etc),
* and the bootrom never check this register, so we need
* to check it and back to bootrom at very early bootstage(before
* some basic configurations(such as interrupts) been
* changed by TPL/SPL, as the bootrom download operation
* relies on many default settings(such as interrupts) by
* itself.
*/
static bool check_back_to_brom_dnl_flag(void)
{
u32 boot_mode;
if (CONFIG_ROCKCHIP_BOOT_MODE_REG) {
boot_mode = readl(CONFIG_ROCKCHIP_BOOT_MODE_REG);
if (boot_mode == BOOT_BROM_DOWNLOAD) {
writel(0, CONFIG_ROCKCHIP_BOOT_MODE_REG);
return true;
}
}
return false;
}
/*
* All Rockchip BROM implementations enter with a valid stack-pointer,
* so this can safely be implemented in C (providing a single
* implementation both for ARMv7 and AArch64).
*/
int save_boot_params(void)
{
int ret = setjmp(brom_ctx);
switch (ret) {
case 0:
if (check_back_to_brom_dnl_flag())
_back_to_bootrom(BROM_BOOT_ENTER_DNL);
/*
* This is the initial pass through this function
* (i.e. saving the context), setjmp just setup up the
* brom_ctx: transfer back into the startup-code at
* 'save_boot_params_ret' and let the compiler know
* that this will not return.
*/
save_boot_params_ret();
while (true)
/* does not return */;
break;
case BROM_BOOT_NEXTSTAGE:
/*
* To instruct the BROM to boot the next stage, we
* need to return 0 to it: i.e. we need to rewrite
* the return code once more.
*/
ret = 0;
break;
case BROM_BOOT_ENTER_DNL:
/*
* A non-zero return value will instruct the BROM enter
* download mode.
*/
ret = 1;
break;
default:
#if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT)
puts("FATAL: unexpected command to back_to_bootrom()\n");
#endif
hang();
};
return ret;
}
|