diff options
Diffstat (limited to 'arch/alpha/boot/bootpz.c')
| -rw-r--r-- | arch/alpha/boot/bootpz.c | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/arch/alpha/boot/bootpz.c b/arch/alpha/boot/bootpz.c new file mode 100644 index 000000000..43af71835 --- /dev/null +++ b/arch/alpha/boot/bootpz.c @@ -0,0 +1,475 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * arch/alpha/boot/bootpz.c + * + * Copyright (C) 1997 Jay Estabrook + * + * This file is used for creating a compressed BOOTP file for the + * Linux/AXP kernel + * + * based significantly on the arch/alpha/boot/main.c of Linus Torvalds + * and the decompression code from MILO. + */ +#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 <asm/io.h> + +#include <stdarg.h> + +#include "kzsize.h" + +/* FIXME FIXME FIXME */ +#define MALLOC_AREA_SIZE 0x200000 /* 2MB for now */ +/* FIXME FIXME FIXME */ + + +/* + WARNING NOTE + + It is very possible that turning on additional messages may cause + kernel image corruption due to stack usage to do the printing. + +*/ + +#undef DEBUG_CHECK_RANGE +#undef DEBUG_ADDRESSES +#undef DEBUG_LAST_STEPS + +extern unsigned long switch_to_osf_pal(unsigned long nr, + struct pcb_struct * pcb_va, struct pcb_struct * pcb_pa, + unsigned long *vptb); + +extern int decompress_kernel(void* destination, void *source, + size_t ksize, size_t kzsize); + +extern void move_stack(unsigned long new_stack); + +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. + */ +#define VPTB ((unsigned long *) 0x200000000) + +static inline unsigned long +find_pa(unsigned long address) +{ + unsigned long result; + + result = VPTB[address >> 13]; + result >>= 32; + result <<= 13; + result |= address & 0x1fff; + return result; +} + +int +check_range(unsigned long vstart, unsigned long vend, + unsigned long kstart, unsigned long kend) +{ + unsigned long vaddr, kaddr; + +#ifdef DEBUG_CHECK_RANGE + srm_printk("check_range: V[0x%lx:0x%lx] K[0x%lx:0x%lx]\n", + vstart, vend, kstart, kend); +#endif + /* do some range checking for detecting an overlap... */ + for (vaddr = vstart; vaddr <= vend; vaddr += PAGE_SIZE) + { + kaddr = (find_pa(vaddr) | PAGE_OFFSET); + if (kaddr >= kstart && kaddr <= kend) + { +#ifdef DEBUG_CHECK_RANGE + srm_printk("OVERLAP: vaddr 0x%lx kaddr 0x%lx" + " [0x%lx:0x%lx]\n", + vaddr, kaddr, kstart, kend); +#endif + return 1; + } + } + return 0; +} + +/* + * 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 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 = (struct pcb_struct *)find_pa((unsigned long)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 */ +} + +/* + * Start the kernel. + */ +static inline void +runkernel(void) +{ + __asm__ __volatile__( + "bis %0,%0,$27\n\t" + "jmp ($27)" + : /* no outputs: it doesn't even return */ + : "r" (START_ADDR)); +} + +/* Must record the SP (it is virtual) on entry, so we can make sure + not to overwrite it during movement or decompression. */ +unsigned long SP_on_entry; + +/* Calculate the kernel image address based on the end of the BOOTP + bootstrapper (ie this program). +*/ +extern char _end; +#define KERNEL_ORIGIN \ + ((((unsigned long)&_end) + 511) & ~511) + +/* Round address to next higher page boundary. */ +#define NEXT_PAGE(a) (((a) | (PAGE_SIZE - 1)) + 1) + +#ifdef INITRD_IMAGE_SIZE +# define REAL_INITRD_SIZE INITRD_IMAGE_SIZE +#else +# define REAL_INITRD_SIZE 0 +#endif + +/* Defines from include/asm-alpha/system.h + + BOOT_ADDR Virtual address at which the consoles loads + the BOOTP image. + + KERNEL_START KSEG address at which the kernel is built to run, + which includes some initial data pages before the + code. + + START_ADDR KSEG address of the entry point of kernel code. + + ZERO_PGE KSEG address of page full of zeroes, but + upon entry to kerne cvan be expected + to hold the parameter list and possible + INTRD information. + + These are used in the local defines below. +*/ + + +/* Virtual addresses for the BOOTP image. Note that this includes the + bootstrapper code as well as the compressed kernel image, and + possibly the INITRD image. + + Oh, and do NOT forget the STACK, which appears to be placed virtually + beyond the end of the loaded image. +*/ +#define V_BOOT_IMAGE_START BOOT_ADDR +#define V_BOOT_IMAGE_END SP_on_entry + +/* Virtual addresses for just the bootstrapper part of the BOOTP image. */ +#define V_BOOTSTRAPPER_START BOOT_ADDR +#define V_BOOTSTRAPPER_END KERNEL_ORIGIN + +/* Virtual addresses for just the data part of the BOOTP + image. This may also include the INITRD image, but always + includes the STACK. +*/ +#define V_DATA_START KERNEL_ORIGIN +#define V_INITRD_START (KERNEL_ORIGIN + KERNEL_Z_SIZE) +#define V_INTRD_END (V_INITRD_START + REAL_INITRD_SIZE) +#define V_DATA_END V_BOOT_IMAGE_END + +/* KSEG addresses for the uncompressed kernel. + + Note that the end address includes workspace for the decompression. + Note also that the DATA_START address is ZERO_PGE, to which we write + just before jumping to the kernel image at START_ADDR. + */ +#define K_KERNEL_DATA_START ZERO_PGE +#define K_KERNEL_IMAGE_START START_ADDR +#define K_KERNEL_IMAGE_END (START_ADDR + KERNEL_SIZE) + +/* Define to where we may have to decompress the kernel image, before + we move it to the final position, in case of overlap. This will be + above the final position of the kernel. + + Regardless of overlap, we move the INITRD image to the end of this + copy area, because there needs to be a buffer area after the kernel + for "bootmem" anyway. +*/ +#define K_COPY_IMAGE_START NEXT_PAGE(K_KERNEL_IMAGE_END) +/* Reserve one page below INITRD for the new stack. */ +#define K_INITRD_START \ + NEXT_PAGE(K_COPY_IMAGE_START + KERNEL_SIZE + PAGE_SIZE) +#define K_COPY_IMAGE_END \ + (K_INITRD_START + REAL_INITRD_SIZE + MALLOC_AREA_SIZE) +#define K_COPY_IMAGE_SIZE \ + NEXT_PAGE(K_COPY_IMAGE_END - K_COPY_IMAGE_START) + +void +start_kernel(void) +{ + int must_move = 0; + + /* Initialize these for the decompression-in-place situation, + which is the smallest amount of work and most likely to + occur when using the normal START_ADDR of the kernel + (currently set to 16MB, to clear all console code. + */ + unsigned long uncompressed_image_start = K_KERNEL_IMAGE_START; + unsigned long uncompressed_image_end = K_KERNEL_IMAGE_END; + + unsigned long initrd_image_start = K_INITRD_START; + + /* + * Note that this crufty stuff with static and envval + * and envbuf is because: + * + * 1. Frequently, the stack is short, and we don't want to overrun; + * 2. Frequently the stack is where we are going to copy the kernel to; + * 3. A certain SRM console required the GET_ENV output to stack. + * ??? A comment in the aboot sources indicates that the GET_ENV + * destination must be quadword aligned. Might this explain the + * behaviour, rather than requiring output to the stack, which + * seems rather far-fetched. + */ + static long nbytes; + static char envval[256] __attribute__((aligned(8))); + register unsigned long asm_sp asm("30"); + + SP_on_entry = asm_sp; + + srm_printk("Linux/Alpha BOOTPZ Loader for Linux " UTS_RELEASE "\n"); + + /* Validity check the HWRPB. */ + if (INIT_HWRPB->pagesize != 8192) { + srm_printk("Expected 8kB pages, got %ldkB\n", + INIT_HWRPB->pagesize >> 10); + return; + } + if (INIT_HWRPB->vptb != (unsigned long) VPTB) { + srm_printk("Expected vptb at %p, got %p\n", + VPTB, (void *)INIT_HWRPB->vptb); + return; + } + + /* PALcode (re)initialization. */ + pal_init(); + + /* Get the parameter list from the console environment variable. */ + nbytes = callback_getenv(ENV_BOOTED_OSFLAGS, envval, sizeof(envval)); + if (nbytes < 0 || nbytes >= sizeof(envval)) { + nbytes = 0; + } + envval[nbytes] = '\0'; + +#ifdef DEBUG_ADDRESSES + srm_printk("START_ADDR 0x%lx\n", START_ADDR); + srm_printk("KERNEL_ORIGIN 0x%lx\n", KERNEL_ORIGIN); + srm_printk("KERNEL_SIZE 0x%x\n", KERNEL_SIZE); + srm_printk("KERNEL_Z_SIZE 0x%x\n", KERNEL_Z_SIZE); +#endif + + /* Since all the SRM consoles load the BOOTP image at virtual + * 0x20000000, we have to ensure that the physical memory + * pages occupied by that image do NOT overlap the physical + * address range where the kernel wants to be run. This + * causes real problems when attempting to cdecompress the + * former into the latter... :-( + * + * So, we may have to decompress/move the kernel/INITRD image + * virtual-to-physical someplace else first before moving + * kernel /INITRD to their final resting places... ;-} + * + * Sigh... + */ + + /* First, check to see if the range of addresses occupied by + the bootstrapper part of the BOOTP image include any of the + physical pages into which the kernel will be placed for + execution. + + We only need check on the final kernel image range, since we + will put the INITRD someplace that we can be sure is not + in conflict. + */ + if (check_range(V_BOOTSTRAPPER_START, V_BOOTSTRAPPER_END, + K_KERNEL_DATA_START, K_KERNEL_IMAGE_END)) + { + srm_printk("FATAL ERROR: overlap of bootstrapper code\n"); + __halt(); + } + + /* Next, check to see if the range of addresses occupied by + the compressed kernel/INITRD/stack portion of the BOOTP + image include any of the physical pages into which the + decompressed kernel or the INITRD will be placed for + execution. + */ + if (check_range(V_DATA_START, V_DATA_END, + K_KERNEL_IMAGE_START, K_COPY_IMAGE_END)) + { +#ifdef DEBUG_ADDRESSES + srm_printk("OVERLAP: cannot decompress in place\n"); +#endif + uncompressed_image_start = K_COPY_IMAGE_START; + uncompressed_image_end = K_COPY_IMAGE_END; + must_move = 1; + + /* Finally, check to see if the range of addresses + occupied by the compressed kernel/INITRD part of + the BOOTP image include any of the physical pages + into which that part is to be copied for + decompression. + */ + while (check_range(V_DATA_START, V_DATA_END, + uncompressed_image_start, + uncompressed_image_end)) + { +#if 0 + uncompressed_image_start += K_COPY_IMAGE_SIZE; + uncompressed_image_end += K_COPY_IMAGE_SIZE; + initrd_image_start += K_COPY_IMAGE_SIZE; +#else + /* Keep as close as possible to end of BOOTP image. */ + uncompressed_image_start += PAGE_SIZE; + uncompressed_image_end += PAGE_SIZE; + initrd_image_start += PAGE_SIZE; +#endif + } + } + + srm_printk("Starting to load the kernel with args '%s'\n", envval); + +#ifdef DEBUG_ADDRESSES + srm_printk("Decompressing the kernel...\n" + "...from 0x%lx to 0x%lx size 0x%x\n", + V_DATA_START, + uncompressed_image_start, + KERNEL_SIZE); +#endif + decompress_kernel((void *)uncompressed_image_start, + (void *)V_DATA_START, + KERNEL_SIZE, KERNEL_Z_SIZE); + + /* + * Now, move things to their final positions, if/as required. + */ + +#ifdef INITRD_IMAGE_SIZE + + /* First, we always move the INITRD image, if present. */ +#ifdef DEBUG_ADDRESSES + srm_printk("Moving the INITRD image...\n" + " from 0x%lx to 0x%lx size 0x%x\n", + V_INITRD_START, + initrd_image_start, + INITRD_IMAGE_SIZE); +#endif + memcpy((void *)initrd_image_start, (void *)V_INITRD_START, + INITRD_IMAGE_SIZE); + +#endif /* INITRD_IMAGE_SIZE */ + + /* Next, we may have to move the uncompressed kernel to the + final destination. + */ + if (must_move) { +#ifdef DEBUG_ADDRESSES + srm_printk("Moving the uncompressed kernel...\n" + "...from 0x%lx to 0x%lx size 0x%x\n", + uncompressed_image_start, + K_KERNEL_IMAGE_START, + (unsigned)KERNEL_SIZE); +#endif + /* + * Move the stack to a safe place to ensure it won't be + * overwritten by kernel image. + */ + move_stack(initrd_image_start - PAGE_SIZE); + + memcpy((void *)K_KERNEL_IMAGE_START, + (void *)uncompressed_image_start, KERNEL_SIZE); + } + + /* Clear the zero page, then move the argument list in. */ +#ifdef DEBUG_LAST_STEPS + srm_printk("Preparing ZERO_PGE...\n"); +#endif + memset((char*)ZERO_PGE, 0, PAGE_SIZE); + strcpy((char*)ZERO_PGE, envval); + +#ifdef INITRD_IMAGE_SIZE + +#ifdef DEBUG_LAST_STEPS + srm_printk("Preparing INITRD info...\n"); +#endif + /* Finally, set the INITRD paramenters for the kernel. */ + ((long *)(ZERO_PGE+256))[0] = initrd_image_start; + ((long *)(ZERO_PGE+256))[1] = INITRD_IMAGE_SIZE; + +#endif /* INITRD_IMAGE_SIZE */ + +#ifdef DEBUG_LAST_STEPS + srm_printk("Doing 'runkernel()'...\n"); +#endif + runkernel(); +} + + /* dummy function, should never be called. */ +void *__kmalloc(size_t size, gfp_t flags) +{ + return (void *)NULL; +} |