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2785dc7b SG |
1 | /* |
2 | * PVH Option ROM for fw_cfg DMA | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | * | |
17 | * Copyright (c) 2019 Red Hat Inc. | |
18 | * Authors: | |
19 | * Stefano Garzarella <sgarzare@redhat.com> | |
20 | */ | |
21 | ||
22 | asm (".code32"); /* this code will be executed in protected mode */ | |
23 | ||
24 | #include <stddef.h> | |
25 | #include <stdint.h> | |
26 | #include "optrom.h" | |
27 | #include "optrom_fw_cfg.h" | |
28 | #include "../../include/hw/xen/start_info.h" | |
29 | ||
30 | #define RSDP_SIGNATURE 0x2052545020445352LL /* "RSD PTR " */ | |
31 | #define RSDP_AREA_ADDR 0x000E0000 | |
32 | #define RSDP_AREA_SIZE 2048 | |
33 | #define EBDA_BASE_ADDR 0x0000040E | |
34 | #define EBDA_SIZE 1024 | |
35 | ||
36 | #define E820_MAXENTRIES 128 | |
37 | #define CMDLINE_BUFSIZE 4096 | |
38 | ||
39 | /* e820 table filled in pvh.S using int 0x15 */ | |
40 | struct pvh_e820_table { | |
41 | uint32_t entries; | |
42 | uint32_t reserved; | |
43 | struct hvm_memmap_table_entry table[E820_MAXENTRIES]; | |
44 | }; | |
45 | ||
46 | struct pvh_e820_table pvh_e820 asm("pvh_e820") __attribute__ ((aligned)); | |
47 | ||
48 | static struct hvm_start_info start_info; | |
b1b876ca | 49 | static struct hvm_modlist_entry ramdisk_mod; |
2785dc7b SG |
50 | static uint8_t cmdline_buffer[CMDLINE_BUFSIZE]; |
51 | ||
52 | ||
53 | /* Search RSDP signature. */ | |
54 | static uintptr_t search_rsdp(uint32_t start_addr, uint32_t end_addr) | |
55 | { | |
56 | uint64_t *rsdp_p; | |
57 | ||
58 | /* RSDP signature is always on a 16 byte boundary */ | |
59 | for (rsdp_p = (uint64_t *)start_addr; rsdp_p < (uint64_t *)end_addr; | |
60 | rsdp_p += 2) { | |
61 | if (*rsdp_p == RSDP_SIGNATURE) { | |
62 | return (uintptr_t)rsdp_p; | |
63 | } | |
64 | } | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | /* Force the asm name without leading underscore, even on Win32. */ | |
70 | extern void pvh_load_kernel(void) asm("pvh_load_kernel"); | |
71 | ||
72 | void pvh_load_kernel(void) | |
73 | { | |
74 | void *cmdline_addr = &cmdline_buffer; | |
b1b876ca SG |
75 | void *kernel_entry, *initrd_addr; |
76 | uint32_t cmdline_size, initrd_size, fw_cfg_version = bios_cfg_version(); | |
2785dc7b SG |
77 | |
78 | start_info.magic = XEN_HVM_START_MAGIC_VALUE; | |
79 | start_info.version = 1; | |
80 | ||
81 | /* | |
82 | * pvh_e820 is filled in the pvh.S before to switch in protected mode, | |
83 | * because we can use int 0x15 only in real mode. | |
84 | */ | |
85 | start_info.memmap_entries = pvh_e820.entries; | |
86 | start_info.memmap_paddr = (uintptr_t)pvh_e820.table; | |
87 | ||
88 | /* | |
89 | * Search RSDP in the main BIOS area below 1 MB. | |
90 | * SeaBIOS store the RSDP in this area, so we try it first. | |
91 | */ | |
92 | start_info.rsdp_paddr = search_rsdp(RSDP_AREA_ADDR, | |
93 | RSDP_AREA_ADDR + RSDP_AREA_SIZE); | |
94 | ||
95 | /* Search RSDP in the EBDA if it is not found */ | |
96 | if (!start_info.rsdp_paddr) { | |
97 | /* | |
98 | * Th EBDA address is stored at EBDA_BASE_ADDR. It contains 2 bytes | |
99 | * segment pointer to EBDA, so we must convert it to a linear address. | |
100 | */ | |
101 | uint32_t ebda_paddr = ((uint32_t)*((uint16_t *)EBDA_BASE_ADDR)) << 4; | |
102 | if (ebda_paddr > 0x400) { | |
103 | uint32_t *ebda = (uint32_t *)ebda_paddr; | |
104 | ||
105 | start_info.rsdp_paddr = search_rsdp(*ebda, *ebda + EBDA_SIZE); | |
106 | } | |
107 | } | |
108 | ||
109 | bios_cfg_read_entry(&cmdline_size, FW_CFG_CMDLINE_SIZE, 4, fw_cfg_version); | |
110 | bios_cfg_read_entry(cmdline_addr, FW_CFG_CMDLINE_DATA, cmdline_size, | |
111 | fw_cfg_version); | |
112 | start_info.cmdline_paddr = (uintptr_t)cmdline_addr; | |
113 | ||
b1b876ca SG |
114 | /* Check if we have the initrd to load */ |
115 | bios_cfg_read_entry(&initrd_size, FW_CFG_INITRD_SIZE, 4, fw_cfg_version); | |
116 | if (initrd_size) { | |
117 | bios_cfg_read_entry(&initrd_addr, FW_CFG_INITRD_ADDR, 4, | |
118 | fw_cfg_version); | |
119 | bios_cfg_read_entry(initrd_addr, FW_CFG_INITRD_DATA, initrd_size, | |
120 | fw_cfg_version); | |
121 | ||
122 | ramdisk_mod.paddr = (uintptr_t)initrd_addr; | |
123 | ramdisk_mod.size = initrd_size; | |
124 | ||
125 | /* The first module is always ramdisk. */ | |
126 | start_info.modlist_paddr = (uintptr_t)&ramdisk_mod; | |
127 | start_info.nr_modules = 1; | |
128 | } | |
129 | ||
2785dc7b SG |
130 | bios_cfg_read_entry(&kernel_entry, FW_CFG_KERNEL_ENTRY, 4, fw_cfg_version); |
131 | ||
132 | asm volatile("jmp *%1" : : "b"(&start_info), "c"(kernel_entry)); | |
133 | } |