cmdline_early.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2#include <linux/types.h>
 3#include <linux/init.h>
 4#include <linux/libfdt.h>
 5#include <linux/string.h>
 6#include <asm/pgtable.h>
 7#include <asm/setup.h>
 8
 9#include "pi.h"
10
11static char early_cmdline[COMMAND_LINE_SIZE];
12
13static char *get_early_cmdline(uintptr_t dtb_pa)
14{
15	const char *fdt_cmdline = NULL;
16	unsigned int fdt_cmdline_size = 0;
17	int chosen_node;
18
19	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
20		chosen_node = fdt_path_offset((void *)dtb_pa, "/chosen");
21		if (chosen_node >= 0) {
22			fdt_cmdline = fdt_getprop((void *)dtb_pa, chosen_node,
23						  "bootargs", NULL);
24			if (fdt_cmdline) {
25				fdt_cmdline_size = strlen(fdt_cmdline);
26				strscpy(early_cmdline, fdt_cmdline,
27					COMMAND_LINE_SIZE);
28			}
29		}
30	}
31
32	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
33	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
34	    fdt_cmdline_size == 0 /* CONFIG_CMDLINE_FALLBACK */) {
35		strlcat(early_cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
36	}
37
38	return early_cmdline;
39}
40
41static u64 match_noXlvl(char *cmdline)
42{
43	if (strstr(cmdline, "no4lvl"))
44		return SATP_MODE_39;
45	else if (strstr(cmdline, "no5lvl"))
46		return SATP_MODE_48;
47
48	return 0;
49}
50
51u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa)
52{
53	char *cmdline = get_early_cmdline(dtb_pa);
54
55	return match_noXlvl(cmdline);
56}
57
58static bool match_nokaslr(char *cmdline)
59{
60	return strstr(cmdline, "nokaslr");
61}
62
63bool set_nokaslr_from_cmdline(uintptr_t dtb_pa)
64{
65	char *cmdline = get_early_cmdline(dtb_pa);
66
67	return match_nokaslr(cmdline);
68}