xref: /openbmc/linux/arch/s390/boot/startup.c (revision 58f9d806)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/string.h>
3 #include <asm/setup.h>
4 #include <asm/sclp.h>
5 #include "compressed/decompressor.h"
6 #include "boot.h"
7 
8 extern char __boot_data_start[], __boot_data_end[];
9 
10 void error(char *x)
11 {
12 	sclp_early_printk("\n\n");
13 	sclp_early_printk(x);
14 	sclp_early_printk("\n\n -- System halted");
15 
16 	disabled_wait(0xdeadbeef);
17 }
18 
19 #ifdef CONFIG_KERNEL_UNCOMPRESSED
20 unsigned long mem_safe_offset(void)
21 {
22 	return vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size;
23 }
24 #endif
25 
26 static void rescue_initrd(void)
27 {
28 	unsigned long min_initrd_addr;
29 
30 	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
31 		return;
32 	if (!INITRD_START || !INITRD_SIZE)
33 		return;
34 	min_initrd_addr = mem_safe_offset();
35 	if (min_initrd_addr <= INITRD_START)
36 		return;
37 	memmove((void *)min_initrd_addr, (void *)INITRD_START, INITRD_SIZE);
38 	INITRD_START = min_initrd_addr;
39 }
40 
41 static void copy_bootdata(void)
42 {
43 	if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size)
44 		error(".boot.data section size mismatch");
45 	memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size);
46 }
47 
48 void startup_kernel(void)
49 {
50 	void *img;
51 
52 	rescue_initrd();
53 	sclp_early_read_info();
54 	store_ipl_parmblock();
55 	setup_boot_command_line();
56 	setup_memory_end();
57 	detect_memory();
58 	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
59 		img = decompress_kernel();
60 		memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);
61 	}
62 	copy_bootdata();
63 	vmlinux.entry();
64 }
65