xref: /openbmc/linux/arch/s390/boot/startup.c (revision 805bc0bc)

// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/elf.h>
#include <asm/setup.h>
#include <asm/kexec.h>
#include <asm/sclp.h>
#include <asm/uv.h>
#include "compressed/decompressor.h"
#include "boot.h"

extern char __boot_data_start[], __boot_data_end[];
extern char __boot_data_preserved_start[], __boot_data_preserved_end[];

void error(char *x)
{
	sclp_early_printk("\n\n");
	sclp_early_printk(x);
	sclp_early_printk("\n\n -- System halted");

	disabled_wait(0xdeadbeef);
}

#ifdef CONFIG_KERNEL_UNCOMPRESSED
unsigned long mem_safe_offset(void)
{
	return vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size;
}
#endif

static void rescue_initrd(unsigned long addr)
{
	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
		return;
	if (!INITRD_START || !INITRD_SIZE)
		return;
	if (addr <= INITRD_START)
		return;
	memmove((void *)addr, (void *)INITRD_START, INITRD_SIZE);
	INITRD_START = addr;
}

static void copy_bootdata(void)
{
	if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size)
		error(".boot.data section size mismatch");
	memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size);
	if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size)
		error(".boot.preserved.data section size mismatch");
	memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size);
}

static void handle_relocs(unsigned long offset)
{
	Elf64_Rela *rela_start, *rela_end, *rela;
	int r_type, r_sym, rc;
	Elf64_Addr loc, val;
	Elf64_Sym *dynsym;

	rela_start = (Elf64_Rela *) vmlinux.rela_dyn_start;
	rela_end = (Elf64_Rela *) vmlinux.rela_dyn_end;
	dynsym = (Elf64_Sym *) vmlinux.dynsym_start;
	for (rela = rela_start; rela < rela_end; rela++) {
		loc = rela->r_offset + offset;
		val = rela->r_addend + offset;
		r_sym = ELF64_R_SYM(rela->r_info);
		if (r_sym)
			val += dynsym[r_sym].st_value;
		r_type = ELF64_R_TYPE(rela->r_info);
		rc = arch_kexec_do_relocs(r_type, (void *) loc, val, 0);
		if (rc)
			error("Unknown relocation type");
	}
}

void startup_kernel(void)
{
	unsigned long safe_addr;
	void *img;

	store_ipl_parmblock();
	safe_addr = mem_safe_offset();
	safe_addr = read_ipl_report(safe_addr);
	uv_query_info();
	rescue_initrd(safe_addr);
	sclp_early_read_info();
	setup_boot_command_line();
	parse_boot_command_line();
	setup_memory_end();
	detect_memory();
	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
		img = decompress_kernel();
		memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);
	}
	copy_bootdata();
	if (IS_ENABLED(CONFIG_RELOCATABLE))
		handle_relocs(0);
	vmlinux.entry();
}