/*
* Linux/i386 loader
* Supports bzImage, zImage and Image format.
*
* Based on work by Steve Gehlbach.
* Portions are taken from mkelfImage.
*
* 2003-09 by SONE Takeshi
*/
#include "config.h"
#include "kernel/kernel.h"
#include "libopenbios/bindings.h"
#include "libopenbios/sys_info.h"
#include "context.h"
#include "segment.h"
#include "loadfs.h"
#define printf printk
#define debug printk
#define strtoull_with_suffix strtol
#define LINUX_PARAM_LOC 0x90000
#define COMMAND_LINE_LOC 0x91000
#define GDT_LOC 0x92000
#define STACK_LOC 0x93000
#define E820MAX 32 /* number of entries in E820MAP */
struct e820entry {
unsigned long long addr; /* start of memory segment */
unsigned long long size; /* size of memory segment */
unsigned long type; /* type of memory segment */
#define E820_RAM 1
#define E820_RESERVED 2
#define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */
#define E820_NVS 4
};
/* The header of Linux/i386 kernel */
struct linux_header {
uint8_t reserved1[0x1f1]; /* 0x000 */
uint8_t setup_sects; /* 0x1f1 */
uint16_t root_flags; /* 0x1f2 */
uint8_t reserved2[6]; /* 0x1f4 */
uint16_t vid_mode; /* 0x1fa */
uint16_t root_dev; /* 0x1fc */
uint16_t boot_sector_magic; /* 0x1fe */
/* 2.00+ */
uint8_t reserved3[2]; /* 0x200 */
uint8_t header_magic[4]; /* 0x202 */
uint16_t protocol_version; /* 0x206 */
uint32_t realmode_swtch; /* 0x208 */
uint16_t start_sys; /* 0x20c */
uint16_t kver_addr; /* 0x20e */
uint8_t type_of_loader; /* 0x210 */
uint8_t loadflags; /* 0x211 */
uint16_t setup_move_size; /* 0x212 */
uint32_t code32_start; /* 0x214 */
uint32_t ramdisk_image; /* 0x218 */
uint32_t ramdisk_size; /* 0x21c */
uint8_t reserved4[4]; /* 0x220 */
/* 2.01+ */
uint16_t heap_end_ptr; /* 0x224 */
uint8_t reserved5[2]; /* 0x226 */
/* 2.02+ */
uint32_t cmd_line_ptr; /* 0x228 */
/* 2.03+ */
uint32_t initrd_addr_max; /* 0x22c */
} __attribute__ ((packed));
/* Paramters passed to 32-bit part of Linux
* This is another view of the structure above.. */
struct linux_params {
uint8_t orig_x; /* 0x00 */
uint8_t orig_y; /* 0x01 */
uint16_t ext_mem_k; /* 0x02 -- EXT_MEM_K sits here */
uint16_t orig_video_page; /* 0x04 */
uint8_t orig_video_mode; /* 0x06 */
uint8_t orig_video_cols; /* 0x07 */
uint16_t unused2; /* 0x08 */
uint16_t orig_video_ega_bx; /* 0x0a */
uint16_t unused3; /* 0x0c */
uint8_t orig_video_lines; /* 0x0e */
uint8_t orig_video_isVGA; /* 0x0f */
uint16_t orig_video_points; /* 0x10 */
/* VESA graphic mode -- linear frame buffer */
uint16_t lfb_width; /* 0x12 */
uint16_t lfb_height; /* 0x14 */
uint16_t lfb_depth; /* 0x16 */
uint32_t lfb_base; /* 0x18 */
uint32_t lfb_size; /* 0x1c */
uint16_t cl_magic; /* 0x20 */
#define CL_MAGIC_VALUE 0xA33F
uint16_t cl_offset; /* 0x22 */
uint16_t lfb_linelength; /* 0x24 */
uint8_t red_size; /* 0x26 */
uint8_t red_pos; /* 0x27 */
uint8_t green_size; /* 0x28 */
uint8_t green_pos; /* 0x29 */
uint8_t blue_size; /* 0x2a */
uint8_t blue_pos; /* 0x2b */
uint8_t rsvd_size; /* 0x2c */
uint8_t rsvd_pos; /* 0x2d */
uint16_t vesapm_seg; /* 0x2e */
uint16_t vesapm_off; /* 0x30 */
uint16_t pages; /* 0x32 */
uint8_t reserved4[12]; /* 0x34 -- 0x3f reserved for future expansion */
//struct apm_bios_info apm_bios_info; /* 0x40 */
uint8_t apm_bios_info[0x40];
//struct drive_info_struct drive_info; /* 0x80 */
uint8_t drive_info[0x20];
//struct sys_desc_table sys_desc_table; /* 0xa0 */
uint8_t sys_desc_table[0x140];
uint32_t alt_mem_k; /* 0x1e0 */
uint8_t reserved5[4]; /* 0x1e4 */
uint8_t e820_map_nr; /* 0x1e8 */
uint8_t reserved6[9]; /* 0x1e9 */
uint16_t mount_root_rdonly; /* 0x1f2 */
uint8_t reserved7[4]; /* 0x1f4 */
uint16_t ramdisk_flags; /* 0x1f8 */
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000
uint8_t reserved8[2]; /* 0x1fa */
uint16_t orig_root_dev; /* 0x1fc */
uint8_t reserved9[1]; /* 0x1fe */
uint8_t aux_device_info; /* 0x1ff */
uint8_t reserved10[2]; /* 0x200 */
uint8_t param_block_signature[4]; /* 0x202 */
uint16_t param_block_version; /* 0x206 */
uint8_t reserved11[8]; /* 0x208 */
uint8_t loader_type; /* 0x210 */
#define LOADER_TYPE_LOADLIN 1
#define LOADER_TYPE_BOOTSECT_LOADER 2
#define LOADER_TYPE_SYSLINUX 3
#define LOADER_TYPE_ETHERBOOT 4
#define LOADER_TYPE_KERNEL 5
uint8_t loader_flags; /* 0x211 */
uint8_t reserved12[2]; /* 0x212 */
uint32_t kernel_start; /* 0x214 */
uint32_t initrd_start; /* 0x218 */
uint32_t initrd_size; /* 0x21c */
uint8_t reserved12_5[8]; /* 0x220 */
uint32_t cmd_line_ptr; /* 0x228 */
uint8_t reserved13[164]; /* 0x22c */
struct e820entry e820_map[E820MAX]; /* 0x2d0 */
uint8_t reserved16[688]; /* 0x550 */
#define COMMAND_LINE_SIZE 256
/* Command line is copied here by 32-bit i386/kernel/head.S.
* So I will follow the boot protocol, rather than putting it
* directly here. --ts1 */
uint8_t command_line[COMMAND_LINE_SIZE]; /* 0x800 */
uint8_t reserved17[1792]; /* 0x900 - 0x1000 */
};
uint64_t forced_memsize;
/* Load the first part the file and check if it's Linux */
static uint32_t load_linux_header(struct linux_header *hdr)
{
int load_high;
uint32_t kern_addr;
if (lfile_read(hdr, sizeof *hdr) != sizeof *hdr) {
debug("Can't read Linux header\n");
return 0;
}
if (hdr->boot_sector_magic != 0xaa55) {
debug("Not a Linux kernel image\n");
return 0;
}
/* Linux is found. Print some information */
if (memcmp(hdr->header_magic, "HdrS", 4) != 0) {
/* This may be floppy disk image or something.
* Perform a simple (incomplete) sanity check. */
if (hdr->setup_sects >= 16
|| file_size() - (hdr->setup_sects<<9) >= 512<<10) {
debug("This looks like a bootdisk image but not like Linux...\n");
return 0;
}
printf("Possible very old Linux");
/* This kernel does not even have a protocol version.
* Force the value. */
hdr->protocol_version = 0; /* pre-2.00 */
} else
printf("Found Linux");
if (hdr->protocol_version >= 0x200 && hdr->kver_addr) {
char kver[256];
file_seek(hdr->kver_addr + 0x200);
if (lfile_read(kver, sizeof kver) != 0) {
kver[255] = 0;
printf(" version %s", kver);
}
}
debug(" (protocol %#x)", hdr->protocol_version);
load_high = 0;
if (hdr->protocol_version >= 0x200) {
debug(" (loadflags %#x)", hdr->loadflags);
load_high = hdr->loadflags & 1;
}
if (load_high) {
printf(" bzImage");
kern_addr = 0x100000;
} else {
printf(" zImage or Image");
kern_addr = 0x1000;
}
printf(".\n");
return kern_addr;
}
/* Set up parameters for 32-bit kernel */
static void
init_linux_params(struct linux_params *params, struct linux_header *hdr)
{
debug("Setting up paramters at %#lx\n", virt_to_phys(params));
memset(params, 0, sizeof *params);
/* Copy some useful values from header */
params->mount_root_rdonly = hdr->root_flags;
params->orig_root_dev = hdr->root_dev;
/* Video parameters.
* This assumes we have VGA in standard 80x25 text mode,
* just like our vga.c does.
* Cursor position is filled later to allow some more printf's. */
params->orig_video_mode = 3;
params->orig_video_cols = 80;
params->orig_video_lines = 25;
params->orig_video_isVGA = 1;
params->orig_video_points = 16;
params->loader_type = 0xff; /* Unregistered Linux loader */
}
/* Memory map */
static void
set_memory_size(struct linux_params *params, struct sys_info *info)
{
int i;
uint64_t end;
uint32_t ramtop = 0;
struct e820entry *linux_map;
struct memrange *filo_map;
linux_map = params->e820_map;
filo_map = info->memrange;
for (i = 0; i < info->n_memranges; i++, linux_map++, filo_map++) {
if (i < E820MAX) {
/* Convert to BIOS e820 style */
linux_map->addr = filo_map->base;
linux_map->size = filo_map->size;
linux_map->type = E820_RAM;
debug("%016Lx - %016Lx\n", linux_map->addr,
linux_map->addr + linux_map->size);
params->e820_map_nr = i+1;
}
/* Find out top of RAM. XXX This ignores hole above 1MB */
end = filo_map->base + filo_map->size;
if (end < (1ULL << 32)) { /* don't count memory above 4GB */
if (end > ramtop)
ramtop = (uint32_t) end;
}
}
debug("ramtop=%#x\n", ramtop);
/* Size of memory above 1MB in KB */
params->alt_mem_k = (ramtop - (1<<20)) >> 10;
/* old style, 64MB max */
if (ramtop >= (64<<20))
params->ext_mem_k = (63<<10);
else
params->ext_mem_k = params->alt_mem_k;
debug("ext_mem_k=%d, alt_mem_k=%d\n", params->ext_mem_k, params->alt_mem_k);
}
/*
* Parse command line
* Some parameters, like initrd=<file>, are not passed to kernel,
* we are responsible to process them.
* Parameters for kernel are copied to kern_cmdline. Returns name of initrd.
*/
static char *parse_command_line(const char *orig_cmdline, char *kern_cmdline)
{
const char *start, *sep, *end, *val;
char name[64];
int len;
int k_len;
int to_kern;
char *initrd = 0;
int toolong = 0;
forced_memsize = 0;
if (!orig_cmdline) {
*kern_cmdline = 0;
return 0;
}
k_len = 0;
debug("original command line: \"%s\"\n", orig_cmdline);
debug("kernel command line at %#lx\n", virt_to_phys(kern_cmdline));
start = orig_cmdline;
while (*start == ' ')
start++;
while (*start) {
end = strchr(start, ' ');
if (!end)
end = start + strlen(start);
sep = strchr(start, '=');
if (!sep || sep > end)
sep = end;
len = sep - start;
if (len >= sizeof(name))
len = sizeof(name) - 1;
memcpy(name, start, len);
name[len] = 0;
if (*sep == '=') {
val = sep + 1;
len = end - val;
} else {
val = 0;
len = 0;
}
/* Only initrd= and mem= are handled here. vga= is not,
* which I believe is a paramter to the realmode part of Linux,
* which we don't execute. */
if (strcmp(name, "initrd") == 0) {
if (!val)
printf("Missing filename to initrd parameter\n");
else {
initrd = malloc(len + 1);
memcpy(initrd, val, len);
initrd[len] = 0;
debug("initrd=%s\n", initrd);
}
/* Don't pass this to kernel */
to_kern = 0;
} else if (strcmp(name, "mem") == 0) {
if (!val)
printf("Missing value for mem parameter\n");
else {
forced_memsize = strtoull_with_suffix(val, (char**)&val, 0);
if (forced_memsize == 0)
printf("Invalid mem option, ignored\n");
if (val != end) {
printf("Garbage after mem=<size>, ignored\n");
forced_memsize = 0;
}
debug("mem=%Lu\n", forced_memsize);
}
/* mem= is for both loader and kernel */
to_kern = 1;
} else
to_kern = 1;
if (to_kern) {
/* Copy to kernel command line buffer */
if (k_len != 0)
kern_cmdline[k_len++] = ' '; /* put separator */
len = end - start;
if (k_len + len >= COMMAND_LINE_SIZE) {
len = COMMAND_LINE_SIZE - k_len - 1;
if (!toolong) {
printf("Kernel command line is too long; truncated to "
"%d bytes\n", COMMAND_LINE_SIZE-1);
toolong = 1;
}
}
memcpy(kern_cmdline + k_len, start, len);
k_len += len;
}
start = end;
while (*start == ' ')
start++;
}
kern_cmdline[k_len] = 0;
debug("kernel command line (%d bytes): \"%s\"\n", k_len, kern_cmdline);
return initrd;
}
/* Set command line location */
static void set_command_line_loc(struct linux_params *params,
struct linux_header *hdr)
{
if (hdr->protocol_version >= 0x202) {
/* new style */
params->cmd_line_ptr = COMMAND_LINE_LOC;
} else {
/* old style */
params->cl_magic = CL_MAGIC_VALUE;
params->cl_offset = COMMAND_LINE_LOC - LINUX_PARAM_LOC;
}
}
/* Load 32-bit part of kernel */
static int load_linux_kernel(struct linux_header *hdr, uint32_t kern_addr)
{
uint32_t kern_offset, kern_size;
if (hdr->setup_sects == 0)
hdr->setup_sects = 4;
kern_offset = (hdr->setup_sects + 1) * 512;
file_seek(kern_offset);
kern_size = file_size() - kern_offset;
debug("offset=%#x addr=%#x size=%#x\n", kern_offset, kern_addr, kern_size);
#if 0
if (using_devsize) {
printf("Attempt to load up to end of device as kernel; "
"specify the image size\n");
return 0;
}
#endif
printf("Loading kernel... ");
if (lfile_read(phys_to_virt(kern_addr), kern_size) != kern_size) {
printf("Can't read kernel\n");
return 0;
}
printf("ok\n");
return kern_size;
}
static int load_initrd(struct linux_header *hdr, struct sys_info *info,
uint32_t kern_end, struct linux_params *params, const char *initrd_file)
{
uint32_t max;
uint32_t start, end, size;
uint64_t forced;
extern char _start[], _end[];
if (!file_open(initrd_file)) {
printf("Can't open initrd: %s\n", initrd_file);
return -1;
}
#if 0
if (using_devsize) {
printf("Attempt to load up to end of device as initrd; "
"specify the image size\n");
return -1;
}
#endif
size = file_size();
/* Find out the kernel's restriction on how high the initrd can be
* placed */
if (hdr->protocol_version >= 0x203)
max = hdr->initrd_addr_max;
else
max = 0x38000000; /* Hardcoded value for older kernels */
/* FILO itself is at the top of RAM. (relocated)
* So, try putting initrd just below us. */
end = virt_to_phys(_start);
if (end > max)
end = max;
/* If "mem=" option is given, we have to put the initrd within
* the specified range. */
if (forced_memsize) {
forced = forced_memsize;
if (forced > max)
forced = max;
/* If the "mem=" is lower, it's easy */
if (forced <= end)
end = forced;
else {
/* Otherwise, see if we can put it above us */
if (virt_to_phys(_end) + size <= forced)
end = forced; /* Ok */
}
}
start = end - size;
start &= ~0xfff; /* page align */
end = start + size;
debug("start=%#x end=%#x\n", start, end);
if (start < kern_end) {
printf("Initrd is too big to fit in memory\n");
return -1;
}
printf("Loading initrd... ");
if (lfile_read(phys_to_virt(start), size) != size) {
printf("Can't read initrd\n");
return -1;
}
printf("ok\n");
params->initrd_start = start;
params->initrd_size = size;
return 0;
}
static void hardware_setup(void)
{
/* Disable nmi */
outb(0x80, 0x70);
/* Make sure any coprocessor is properly reset.. */
outb(0, 0xf0);
outb(0, 0xf1);
/* we're getting screwed again and again by this problem of the 8259.
* so we're going to leave this lying around for inclusion into
* crt0.S on an as-needed basis.
*
* well, that went ok, I hope. Now we have to reprogram the interrupts :-(
* we put them right after the intel-reserved hardware interrupts, at
* int 0x20-0x2F. There they won't mess up anything. Sadly IBM really
* messed this up with the original PC, and they haven't been able to
* rectify it afterwards. Thus the bios puts interrupts at 0x08-0x0f,
* which is used for the internal hardware interrupts as well. We just
* have to reprogram the 8259's, and it isn't fun.
*/
outb(0x11, 0x20); /* initialization sequence to 8259A-1 */
outb(0x11, 0xA0); /* and to 8259A-2 */
outb(0x20, 0x21); /* start of hardware int's (0x20) */
outb(0x28, 0xA1); /* start of hardware int's 2 (0x28) */
outb(0x04, 0x21); /* 8259-1 is master */
outb(0x02, 0xA1); /* 8259-2 is slave */
outb(0x01, 0x21); /* 8086 mode for both */
outb(0x01, 0xA1);
outb(0xFF, 0xA1); /* mask off all interrupts for now */
outb(0xFB, 0x21); /* mask all irq's but irq2 which is cascaded */
}
/* Start Linux */
static int start_linux(uint32_t kern_addr, struct linux_params *params)
{
struct segment_desc *linux_gdt;
struct context *ctx;
//extern int cursor_x, cursor_y;
ctx = init_context(phys_to_virt(STACK_LOC), 4096, 0);
/* Linux expects GDT being in low memory */
linux_gdt = phys_to_virt(GDT_LOC);
memset(linux_gdt, 0, 13*sizeof(struct segment_desc));
/* Normal kernel code/data segments */
linux_gdt[2] = gdt[FLAT_CODE];
linux_gdt[3] = gdt[FLAT_DATA];
/* 2.6 kernel uses 12 and 13, but head.S uses backward-compatible
* segments (2 and 3), so it SHOULD not be a problem.
* However, some distro kernels (eg. RH9) with backported threading
* patch use 12 and 13 also when booting... */
linux_gdt[12] = gdt[FLAT_CODE];
linux_gdt[13] = gdt[FLAT_DATA];
ctx->gdt_base = GDT_LOC;
ctx->gdt_limit = 14*8-1;
ctx->cs = 0x10;
ctx->ds = 0x18;
ctx->es = 0x18;
ctx->fs = 0x18;
ctx->gs = 0x18;
ctx->ss = 0x18;
/* Parameter location */
ctx->esi = virt_to_phys(params);
/* Entry point */
ctx->eip = kern_addr;
debug("eip=%#x\n", kern_addr);
printf("Jumping to entry point...\n");
#ifdef VGA_CONSOLE
/* Update VGA cursor position.
* This must be here because the printf changes the value! */
params->orig_x = cursor_x;
params->orig_y = cursor_y;
#endif
/* Go... */
ctx = switch_to(ctx);
/* It's impossible but... */
printf("Returned with eax=%#x\n", ctx->eax);
return ctx->eax;
}
int linux_load(struct sys_info *info, const char *file, const char *cmdline)
{
struct linux_header hdr;
struct linux_params *params;
uint32_t kern_addr, kern_size;
char *initrd_file = 0;
if (!file_open(file))
return -1;
kern_addr = load_linux_header(&hdr);
if (kern_addr == 0)
return LOADER_NOT_SUPPORT;
params = phys_to_virt(LINUX_PARAM_LOC);
init_linux_params(params, &hdr);
set_memory_size(params, info);
initrd_file = parse_command_line(cmdline, phys_to_virt(COMMAND_LINE_LOC));
set_command_line_loc(params, &hdr);
kern_size = load_linux_kernel(&hdr, kern_addr);
if (kern_size == 0) {
if (initrd_file)
free(initrd_file);
return -1;
}
if (initrd_file) {
if (load_initrd(&hdr, info, kern_addr+kern_size, params, initrd_file)
!= 0) {
free(initrd_file);
return -1;
}
free(initrd_file);
}
hardware_setup();
start_linux(kern_addr, params);
return 0;
}