1*4882a593Smuzhiyun /**
2*4882a593Smuzhiyun * Copyright (c) 2017 Google, Inc
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * SPDX-License-Identifier: GPL-2.0+
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <common.h>
8*4882a593Smuzhiyun #include <asm/arch/bootrom.h>
9*4882a593Smuzhiyun #include <asm/arch/boot_mode.h>
10*4882a593Smuzhiyun #include <asm/io.h>
11*4882a593Smuzhiyun #include <asm/setjmp.h>
12*4882a593Smuzhiyun #include <asm/system.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun /*
15*4882a593Smuzhiyun * Force the jmp_buf to the data-section, as .bss will not be valid
16*4882a593Smuzhiyun * when save_boot_params is invoked.
17*4882a593Smuzhiyun */
18*4882a593Smuzhiyun static jmp_buf brom_ctx __section(".data");
19*4882a593Smuzhiyun
_back_to_bootrom(enum rockchip_bootrom_cmd brom_cmd)20*4882a593Smuzhiyun static void _back_to_bootrom(enum rockchip_bootrom_cmd brom_cmd)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun longjmp(brom_ctx, brom_cmd);
23*4882a593Smuzhiyun }
24*4882a593Smuzhiyun
back_to_bootrom(enum rockchip_bootrom_cmd brom_cmd)25*4882a593Smuzhiyun void back_to_bootrom(enum rockchip_bootrom_cmd brom_cmd)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT)
28*4882a593Smuzhiyun puts("Returning to boot ROM...\n");
29*4882a593Smuzhiyun #endif
30*4882a593Smuzhiyun _back_to_bootrom(brom_cmd);
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun /*
34*4882a593Smuzhiyun * We back to bootrom download mode if get a
35*4882a593Smuzhiyun * BOOT_BROM_DOWNLOAD flag in boot mode register
36*4882a593Smuzhiyun *
37*4882a593Smuzhiyun * The bootrom never check this register, so we need
38*4882a593Smuzhiyun * to check it and back to bootrom at very early bootstage(before
39*4882a593Smuzhiyun * some basic configurations(such as interrupts) been
40*4882a593Smuzhiyun * changed by TPL/SPL, as the bootrom download operation
41*4882a593Smuzhiyun * relys on many default settings(such as interrupts) by
42*4882a593Smuzhiyun * it's self.
43*4882a593Smuzhiyun * Note: the boot mode register is configured by
44*4882a593Smuzhiyun * application(next stage bootloader, kernel, etc) via command or PC Tool,
45*4882a593Smuzhiyun * cleared by USB download(bootrom mode) or loader(other mode) after the
46*4882a593Smuzhiyun * tag has work.
47*4882a593Smuzhiyun */
check_back_to_brom_dnl_flag(void)48*4882a593Smuzhiyun static bool check_back_to_brom_dnl_flag(void)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun u32 boot_mode, boot_id;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun if (CONFIG_ROCKCHIP_BOOT_MODE_REG && BROM_BOOTSOURCE_ID_ADDR) {
53*4882a593Smuzhiyun boot_mode = readl(CONFIG_ROCKCHIP_BOOT_MODE_REG);
54*4882a593Smuzhiyun boot_id = readl(BROM_BOOTSOURCE_ID_ADDR);
55*4882a593Smuzhiyun if (boot_id == BROM_BOOTSOURCE_USB)
56*4882a593Smuzhiyun writel(0, CONFIG_ROCKCHIP_BOOT_MODE_REG);
57*4882a593Smuzhiyun else if (boot_mode == BOOT_BROM_DOWNLOAD)
58*4882a593Smuzhiyun return true;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun return false;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun /*
65*4882a593Smuzhiyun * All Rockchip BROM implementations enter with a valid stack-pointer,
66*4882a593Smuzhiyun * so this can safely be implemented in C (providing a single
67*4882a593Smuzhiyun * implementation both for ARMv7 and AArch64).
68*4882a593Smuzhiyun */
save_boot_params(void)69*4882a593Smuzhiyun int save_boot_params(void)
70*4882a593Smuzhiyun {
71*4882a593Smuzhiyun int ret = setjmp(brom_ctx);
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun switch (ret) {
74*4882a593Smuzhiyun case 0:
75*4882a593Smuzhiyun if (check_back_to_brom_dnl_flag())
76*4882a593Smuzhiyun _back_to_bootrom(BROM_BOOT_ENTER_DNL);
77*4882a593Smuzhiyun /*
78*4882a593Smuzhiyun * This is the initial pass through this function
79*4882a593Smuzhiyun * (i.e. saving the context), setjmp just setup up the
80*4882a593Smuzhiyun * brom_ctx: transfer back into the startup-code at
81*4882a593Smuzhiyun * 'save_boot_params_ret' and let the compiler know
82*4882a593Smuzhiyun * that this will not return.
83*4882a593Smuzhiyun */
84*4882a593Smuzhiyun save_boot_params_ret();
85*4882a593Smuzhiyun while (true)
86*4882a593Smuzhiyun /* does not return */;
87*4882a593Smuzhiyun break;
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun case BROM_BOOT_NEXTSTAGE:
90*4882a593Smuzhiyun /*
91*4882a593Smuzhiyun * To instruct the BROM to boot the next stage, we
92*4882a593Smuzhiyun * need to return 0 to it: i.e. we need to rewrite
93*4882a593Smuzhiyun * the return code once more.
94*4882a593Smuzhiyun */
95*4882a593Smuzhiyun ret = 0;
96*4882a593Smuzhiyun break;
97*4882a593Smuzhiyun case BROM_BOOT_ENTER_DNL:
98*4882a593Smuzhiyun /*
99*4882a593Smuzhiyun * A non-zero return value will instruct the BROM enter
100*4882a593Smuzhiyun * download mode.
101*4882a593Smuzhiyun */
102*4882a593Smuzhiyun ret = 1;
103*4882a593Smuzhiyun break;
104*4882a593Smuzhiyun default:
105*4882a593Smuzhiyun #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT)
106*4882a593Smuzhiyun puts("FATAL: unexpected command to back_to_bootrom()\n");
107*4882a593Smuzhiyun #endif
108*4882a593Smuzhiyun hang();
109*4882a593Smuzhiyun };
110*4882a593Smuzhiyun
111*4882a593Smuzhiyun return ret;
112*4882a593Smuzhiyun }
113