blob: bfae39ea522e35837c55d69777cfe37d7798fea6 (
plain)
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
|
// SPDX-License-Identifier: GPL-2.0-only
#include <asm/barebox-arm.h>
#include <common.h>
#include <image-metadata.h>
#include <debug_ll.h>
#include <firmware.h>
#include <mach/atf.h>
#include <mach/esdctl.h>
#include <mach/generic.h>
#include <mach/imx8m-ccm-regs.h>
#include <mach/imx8mm-regs.h>
#include <mach/iomux-mx8mm.h>
#include <mach/xload.h>
#include <soc/fsl/fsl_udc.h>
#include <soc/imx8m/ddr.h>
extern char __dtb_z_imx8mm_prt8mm_start[];
#define UART_PAD_CTRL MUX_PAD_CTRL(PAD_CTL_DSE_3P3V_45_OHM)
static void setup_uart(void)
{
void __iomem *uart = IOMEM(MX8M_UART4_BASE_ADDR);
imx8m_early_setup_uart_clock();
imx8mm_setup_pad(IMX8MM_PAD_UART4_TXD_UART4_TX | UART_PAD_CTRL);
imx8m_uart_setup(uart);
pbl_set_putc(imx_uart_putc, uart);
putc_ll('>');
}
extern struct dram_timing_info prt8mm_dram_timing;
static void start_atf(void)
{
/*
* If we are in EL3 we are running for the first time and need to
* initialize the DRAM and run TF-A (BL31). The TF-A will then jump
* to DRAM in EL2.
*/
if (current_el() != 3)
return;
imx8mm_early_clock_init();
imx8mm_ddr_init(&prt8mm_dram_timing, DRAM_TYPE_LPDDR4);
imx8mm_load_and_start_image_via_tfa();
}
/*
* Power-on execution flow of start_prt_prt8mm() might not be
* obvious for a very first read, so here's, hopefully helpful,
* summary:
*
* 1. MaskROM uploads PBL into OCRAM and that's where this function is
* executed for the first time. At entry the exception level is EL3.
*
* 2. DDR is initialized and the image is loaded from storage into DRAM. The PBL
* part is copied from OCRAM to the TF-A return address in DRAM.
*
* 3. TF-A is executed and exits into the PBL code in DRAM. TF-A has taken us
* from EL3 to EL2.
*
* 4. Standard barebox boot flow continues
*/
static __noreturn noinline void prt_prt8mm_start(void)
{
setup_uart();
start_atf();
/*
* Standard entry we hit once we initialized both DDR and ATF
*/
imx8mm_barebox_entry(__dtb_z_imx8mm_prt8mm_start);
}
ENTRY_FUNCTION(start_prt_prt8mm, r0, r1, r2)
{
imx8mm_cpu_lowlevel_init();
relocate_to_current_adr();
setup_c();
IMD_USED_OF(imx8mm_prt8mm);
prt_prt8mm_start();
}
|
