Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * arch/alpha/boot/main.c
 *
 * Copyright (C) 1994, 1995 Linus Torvalds
 *
 * This file is the bootloader for the Linux/AXP kernel
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <generated/utsrelease.h>
#include <linux/mm.h>
 
#include <asm/console.h>
#include <asm/hwrpb.h>
 
#include <stdarg.h>
 
#include "ksize.h"
 
extern unsigned long switch_to_osf_pal(unsigned long nr,
<------>struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa,
<------>unsigned long *vptb);
struct hwrpb_struct *hwrpb = INIT_HWRPB;
static struct pcb_struct pcb_va[1];
 
/*
 * Find a physical address of a virtual object..
 *
 * This is easy using the virtual page table address.
 */
 
static inline void *
find_pa(unsigned long *vptb, void *ptr)
{
<------>unsigned long address = (unsigned long) ptr;
<------>unsigned long result;
 
<------>result = vptb[address >> 13];
<------>result >>= 32;
<------>result <<= 13;
<------>result |= address & 0x1fff;
<------>return (void *) result;
}	
 
/*
 * This function moves into OSF/1 pal-code, and has a temporary
 * PCB for that. The kernel proper should replace this PCB with
 * the real one as soon as possible.
 *
 * The page table muckery in here depends on the fact that the boot
 * code has the L1 page table identity-map itself in the second PTE
 * in the L1 page table. Thus the L1-page is virtually addressable
 * itself (through three levels) at virtual address 0x200802000.
 */
 
#define VPTB	((unsigned long *) 0x200000000)
#define L1	((unsigned long *) 0x200802000)
 
void
pal_init(void)
{
<------>unsigned long i, rev;
<------>struct percpu_struct * percpu;
<------>struct pcb_struct * pcb_pa;
 
<------>/* Create the dummy PCB.  */
<------>pcb_va->ksp = 0;
<------>pcb_va->usp = 0;
<------>pcb_va->ptbr = L1[1] >> 32;
<------>pcb_va->asn = 0;
<------>pcb_va->pcc = 0;
<------>pcb_va->unique = 0;
<------>pcb_va->flags = 1;
<------>pcb_va->res1 = 0;
<------>pcb_va->res2 = 0;
<------>pcb_pa = find_pa(VPTB, pcb_va);
 
<------>/*
<------> * a0 = 2 (OSF)
<------> * a1 = return address, but we give the asm the vaddr of the PCB
<------> * a2 = physical addr of PCB
<------> * a3 = new virtual page table pointer
<------> * a4 = KSP (but the asm sets it)
<------> */
<------>srm_printk("Switching to OSF PAL-code .. ");
 
<------>i = switch_to_osf_pal(2, pcb_va, pcb_pa, VPTB);
<------>if (i) {
<------><------>srm_printk("failed, code %ld\n", i);
<------><------>__halt();
<------>}
 
<------>percpu = (struct percpu_struct *)
<------><------>(INIT_HWRPB->processor_offset + (unsigned long) INIT_HWRPB);
<------>rev = percpu->pal_revision = percpu->palcode_avail[2];
 
<------>srm_printk("Ok (rev %lx)\n", rev);
 
<------>tbia(); /* do it directly in case we are SMP */
}
 
static inline long openboot(void)
{
<------>char bootdev[256];
<------>long result;
 
<------>result = callback_getenv(ENV_BOOTED_DEV, bootdev, 255);
<------>if (result < 0)
<------><------>return result;
<------>return callback_open(bootdev, result & 255);
}
 
static inline long close(long dev)
{
<------>return callback_close(dev);
}
 
static inline long load(long dev, unsigned long addr, unsigned long count)
{
<------>char bootfile[256];
<------>extern char _end;
<------>long result, boot_size = &_end - (char *) BOOT_ADDR;
 
<------>result = callback_getenv(ENV_BOOTED_FILE, bootfile, 255);
<------>if (result < 0)
<------><------>return result;
<------>result &= 255;
<------>bootfile[result] = '\0';
<------>if (result)
<------><------>srm_printk("Boot file specification (%s) not implemented\n",
<------><------>       bootfile);
<------>return callback_read(dev, count, (void *)addr, boot_size/512 + 1);
}
 
/*
 * Start the kernel.
 */
static void runkernel(void)
{
<------>__asm__ __volatile__(
<------><------>"bis %1,%1,$30\n\t"
<------><------>"bis %0,%0,$26\n\t"
<------><------>"ret ($26)"
<------><------>: /* no outputs: it doesn't even return */
<------><------>: "r" (START_ADDR),
<------><------>  "r" (PAGE_SIZE + INIT_STACK));
}
 
void start_kernel(void)
{
<------>long i;
<------>long dev;
<------>int nbytes;
<------>char envval[256];
 
<------>srm_printk("Linux/AXP bootloader for Linux " UTS_RELEASE "\n");
<------>if (INIT_HWRPB->pagesize != 8192) {
<------><------>srm_printk("Expected 8kB pages, got %ldkB\n", INIT_HWRPB->pagesize >> 10);
<------><------>return;
<------>}
<------>pal_init();
<------>dev = openboot();
<------>if (dev < 0) {
<------><------>srm_printk("Unable to open boot device: %016lx\n", dev);
<------><------>return;
<------>}
<------>dev &= 0xffffffff;
<------>srm_printk("Loading vmlinux ...");
<------>i = load(dev, START_ADDR, KERNEL_SIZE);
<------>close(dev);
<------>if (i != KERNEL_SIZE) {
<------><------>srm_printk("Failed (%lx)\n", i);
<------><------>return;
<------>}
 
<------>nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval));
<------>if (nbytes < 0) {
<------><------>nbytes = 0;
<------>}
<------>envval[nbytes] = '\0';
<------>strcpy((char*)ZERO_PGE, envval);
 
<------>srm_printk(" Ok\nNow booting the kernel\n");
<------>runkernel();
<------>for (i = 0 ; i < 0x100000000 ; i++)
<------><------>/* nothing */;
<------>__halt();
}