Imported a bunch of C code from KarlOS + bootboot

This commit is contained in:
Thomas Oltmann 2025-07-07 02:38:36 +02:00
parent 94919ad0c7
commit fcdea29944
4 changed files with 489 additions and 5 deletions

View file

@ -19,5 +19,5 @@ boot.elf: lboot.o loader.o fernlader.ld
lboot.o: lboot.S lboot.o: lboot.S
$(CC) $(CFLAGS) -c -o $@ $(@:.o=.S) $(CC) $(CFLAGS) -c -o $@ $(@:.o=.S)
loader.o: loader.c loader.o: loader.c bootboot.h fs.h
$(CC) $(CFLAGS) -m64 -Os -c -o $@ $(@:.o=.c) $(CC) $(CFLAGS) -m64 -Os -c -o $@ $(@:.o=.c)

358
fs.h Normal file
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@ -0,0 +1,358 @@
/*
* x86_64-cb/fs.h
*
* Copyright (C) 2017 - 2021 bzt (bztsrc@gitlab)
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* This file is part of the BOOTBOOT Protocol package.
* @brief Filesystem drivers for initial ramdisk.
*
*/
#define DBG(...) do {} while (0)
#if 0
/**
* FS/Z initrd (OS/Z's native file system)
*/
file_t fsz_initrd(unsigned char *initrd_p, char *kernel)
{
file_t ret = { NULL, 0 };
if(initrd_p==NULL || memcmp(initrd_p + 512,"FS/Z",4) || kernel==NULL){
return ret;
}
unsigned char passphrase[256],chk[32],iv[32];
unsigned int i,j,k,l,ss=1<<(initrd_p[518]+11);
unsigned char *ent, *in=(initrd_p+*((uint64_t*)(initrd_p+560))*ss);
SHA256_CTX ctx;
DBG(" * FS/Z %s\n",kernel);
//decrypt initrd
if(*((uint32_t*)(initrd_p+520))!=0 && (initrd_p[519]&&0xF0)!=0) {
printf("BOOTBOOT-PANIC: Unsupported cipher\n");
return ret;
}
while(*((uint32_t*)(initrd_p+520))!=0) {
printf(" * Passphrase? ");
l=ReadLine(passphrase,sizeof(passphrase));
if(!l) {
printf("\n");
return ret;
}
if(*((uint32_t*)(initrd_p+520))!=crc32_calc((char*)passphrase,l)) {
printf("\rBOOTBOOT-ERROR: Bad passphrase\n");
continue;
}
printf("\r * Decrypting...\r");
SHA256_Init(&ctx);
SHA256_Update(&ctx,passphrase,l);
SHA256_Update(&ctx,initrd_p+512,6);
SHA256_Final(chk,&ctx);
for(i=0;i<32;i++) initrd_p[i+680]^=chk[i];
SHA256_Init(&ctx);
SHA256_Update(&ctx,initrd_p+680,32);
SHA256_Final(iv,&ctx);
// FSZ_SB_EALG_SHACBC
for(k=ss,j=1;j<*((uint32_t*)(initrd_p+528));j++) {
memcpy(chk,iv,32);
for(i=0;i<ss;i++) {
if(i%32==0) {
SHA256_Init(&ctx);
SHA256_Update(&ctx,&chk,32);
SHA256_Update(&ctx,&j,4);
SHA256_Final(chk,&ctx);
}
initrd_p[k++]^=chk[i%32]^iv[i%32];
}
}
memset(initrd_p+680,0,32); *((uint32_t*)(initrd_p+520)) = 0;
*((uint32_t*)(initrd_p+1020))=crc32_calc((char *)initrd_p+512,508);
printf(" \r");
}
// Get the inode
char *s,*e;
s=e=kernel;
i=0;
again:
while(*e!='/'&&*e!=0){e++;}
if(*e=='/'){e++;}
if(!memcmp(in,"FSIN",4)){
//is it inlined?
if(!memcmp(initrd_p[520]&1? in + 2048 : in + 1024,"FSDR",4)){
ent=(initrd_p[520]&1? in + 2048 : in + 1024);
} else if(!memcmp(initrd_p+*((uint64_t*)(in+448))*ss,"FSDR",4)){
// go, get the sector pointed
ent=(initrd_p+*((uint64_t*)(in+448))*ss);
} else {
return ret;
}
//skip header
unsigned char *hdr=ent; ent+=128;
//iterate on directory entries
int j=*((uint64_t*)(hdr+16));
while(j-->0){
if(!memcmp(ent + 16,s,e-s)) {
if(*e==0) {
i=*((uint64_t*)(ent+0));
break;
} else {
s=e;
in=(initrd_p+*((uint64_t*)(ent+0))*ss);
goto again;
}
}
ent+=128;
}
} else {
i=0;
}
if(i!=0) {
// fid -> inode ptr -> data ptr
unsigned char *in=(initrd_p+i*ss);
if(!memcmp(in,"FSIN",4)){
ret.size=*((uint64_t*)(in+464));
if(*((uint64_t*)(in+448)) == i) {
if(!(in[488]&31)) {
// inline data
ret.ptr=(uint8_t*)(initrd_p+i*ss+(initrd_p[520]&1? 2048 : 1024));
} else {
// sector directory or list inlined
ret.ptr=(uint8_t*)(initrd_p + *((uint64_t*)(initrd_p[520]&1? in + 2048 : in + 1024))*ss);
}
} else
if(*((uint64_t*)(in+448))) {
switch((in[488]&15) + (in[488]&16 ? 1 : 0)) {
case 0: // direct data
ret.ptr=(uint8_t*)(initrd_p + *((uint64_t*)(in+448)) * ss);
break;
case 1: // sector directory or list (only one level supported here, and no holes in files)
ret.ptr=(uint8_t*)(initrd_p + *((uint64_t*)(initrd_p + *((uint64_t*)(in+448))*ss)) * ss);
break;
}
} else ret.size=0;
}
}
return ret;
}
#endif
/**
* Minix3 file system
* directories only checked for their first block, and kernel must be defragmented
*/
file_t mfs_initrd(unsigned char *initrd_p, char *kernel)
{
uint32_t o, bs, ino_tbl;
uint8_t *ino, *d;
char *s = kernel, *e;
file_t ret = { NULL, 0 };
if(initrd_p[1048] != 'Z' || initrd_p[1049] != 'M') return ret;
DBG(" * MFS %s\n",kernel);
bs = *((uint16_t*)(initrd_p + 1052));
ino_tbl = (2 + *((uint16_t*)(initrd_p + 1030)) + *((uint16_t*)(initrd_p + 1032))) * bs;
ino = initrd_p + ino_tbl;
again:
for(e = s; *e && *e != '/'; e++);
d = initrd_p + *((uint32_t*)(ino + 24)) * bs;
for(o = 0; o < *((uint32_t*)(ino + 8)) && o < bs; o += 64, d += 64) {
if(*((uint32_t*)d) && !memcmp(s, d + 4, e - s) && !d[e - s]) {
ino = initrd_p + ino_tbl + (*((uint32_t*)d) - 1) * 64;
d = initrd_p + *((uint32_t*)(ino + 24)) * bs;
if(!*e) { ret.ptr = d; ret.size = *((uint32_t*)(ino + 8)); return ret; }
s = e + 1; goto again;
}
}
return ret;
}
/**
* cpio archive
*/
file_t cpio_initrd(unsigned char *initrd_p, char *kernel)
{
unsigned char *ptr=initrd_p;
int k;
file_t ret = { NULL, 0 };
if(initrd_p==NULL || kernel==NULL ||
(memcmp(initrd_p,"070701",6) && memcmp(initrd_p,"070702",6) && memcmp(initrd_p,"070707",6)))
return ret;
DBG(" * cpio %s\n",kernel);
k=strlen(kernel);
// hpodc archive
while(!memcmp(ptr,"070707",6)){
int ns=octbin(ptr+8*6+11,6);
int fs=octbin(ptr+8*6+11+6,11);
if(!memcmp(ptr+9*6+2*11,kernel,k+1) ||
(ptr[9*6+2*11] == '.' && ptr[9*6+2*11+1] == '/' && !memcmp(ptr+9*6+2*11+2,kernel,k+1))) {
ret.size=fs;
ret.ptr=(uint8_t*)(ptr+9*6+2*11+ns);
return ret;
}
ptr+=(76+ns+fs);
}
// newc and crc archive
while(!memcmp(ptr,"07070",5)){
int fs=hexbin(ptr+8*6+6,8);
int ns=hexbin(ptr+8*11+6,8);
if(!memcmp(ptr+110,kernel,k+1) || (ptr[110] == '.' && ptr[111] == '/' && !memcmp(ptr+112,kernel,k+1))) {
ret.size=fs;
ret.ptr=(uint8_t*)(ptr+((110+ns+3)/4)*4);
return ret;
}
ptr+=((110+ns+3)/4)*4 + ((fs+3)/4)*4;
}
return ret;
}
/**
* ustar tarball archive
*/
file_t tar_initrd(unsigned char *initrd_p, char *kernel)
{
unsigned char *ptr=initrd_p;
int k;
file_t ret = { NULL, 0 };
if(initrd_p==NULL || kernel==NULL || memcmp(initrd_p+257,"ustar",5))
return ret;
DBG(" * tar %s\n",kernel);
k=strlen(kernel);
while(!memcmp(ptr+257,"ustar",5)){
int fs=octbin(ptr+0x7c,11);
if(!memcmp(ptr,kernel,k+1) || (ptr[0] == '.' && ptr[1] == '/' && !memcmp(ptr+2,kernel,k+1))) {
ret.size=fs;
ret.ptr=(uint8_t*)(ptr+512);
return ret;
}
ptr+=(((fs+511)/512)+1)*512;
}
return ret;
}
/**
* Simple File System
*/
file_t sfs_initrd(unsigned char *initrd_p, char *kernel)
{
unsigned char *ptr, *end;
int k,bs,ver;
file_t ret = { NULL, 0 };
if(initrd_p==NULL || kernel==NULL || (memcmp(initrd_p+0x1AC,"SFS",3) && memcmp(initrd_p+0x1A6,"SFS",3)))
return ret;
// 1.0 Brendan's version, 1.10 BenLunt's version
ver=!memcmp(initrd_p+0x1A6,"SFS",3)?10:0;
bs=1<<(7+(uint8_t)initrd_p[ver?0x1B6:0x1BC]);
end=initrd_p + *((uint64_t *)&initrd_p[ver?0x1AA:0x1B0]) * bs; // base + total_number_of_blocks * blocksize
// get index area
ptr=end - *((uint64_t *)&initrd_p[ver?0x19E:0x1A4]); // end - size of index area
// got a Starting Marker Entry?
if(ptr[0]!=2)
return ret;
DBG(" * SFS 1.%s %s\n", ver?"10":"0",kernel);
k=strlen(kernel);
// iterate on index until we reach the end or Volume Identifier
while(ptr<end && ptr[0]!=0x01){
ptr+=64;
// file entry?
if(ptr[0]!=0x12)
continue;
// filename match?
if(!memcmp(ptr+(ver?0x23:0x22),kernel,k+1)){
ret.size=*((uint64_t*)&ptr[ver?0x1B:0x1A]); // file_length
ret.ptr=initrd_p + *((uint64_t*)&ptr[ver?0x0B:0x0A]) * bs; // base + start_block * blocksize
break;
}
}
return ret;
}
/**
* James Molloy's initrd (for some reason it's popular among hobby OS developers)
* http://www.jamesmolloy.co.uk/tutorial_html
*/
file_t jamesm_initrd(unsigned char *initrd_p, char *kernel)
{
unsigned char *ptr=initrd_p+4;
int i,k,nf=*((int*)initrd_p);
file_t ret = { NULL, 0 };
// no real magic, so we assume initrd contains at least one file...
if(initrd_p==NULL || kernel==NULL || initrd_p[2]!=0 || initrd_p[3]!=0 || initrd_p[4]!=0xBF)
return ret;
DBG(" * JamesM %s\n",kernel);
k=strlen(kernel);
for(i=0;i<nf && ptr[0]==0xBF;i++) {
if(!memcmp(ptr+1,kernel,k+1)){
ret.ptr=*((uint32_t*)(ptr+65)) + initrd_p;
ret.size=*((uint32_t*)(ptr+69));
}
ptr+=73;
}
return ret;
}
/**
* EchFS
* http://github.com/echfs/echfs
*/
file_t ech_initrd(unsigned char *initrd_p, char *kernel)
{
uint64_t parent = 0xffffffffffffffffUL, n;
unsigned char *ptr;
char *end, *fn;
int k = 0;
file_t ret = { NULL, 0 };
if(initrd_p==NULL || kernel==NULL || memcmp(initrd_p+4,"_ECH_FS_",8))
return ret;
DBG(" * EchFS %s\n",kernel);
memcpy(&k, initrd_p + 28, 4);
memcpy(&n, initrd_p + 12, 8);
ptr = initrd_p + (((n * 8 + k - 1) / k) + 16) * k;
for(end = fn = kernel; *end && *end != '/'; end++);
while(*((uint64_t*)ptr)) {
if(*((uint64_t*)ptr) == parent && !memcmp(ptr + 9, fn, end - fn) && !ptr[9 + end - fn]) {
parent = *((uint64_t*)(ptr + 240));
if(!*end) {
ret.size=*((uint64_t*)(ptr + 248));
ret.ptr=(uint8_t*)(initrd_p + parent * k);
break;
}
end++;
for(fn = end; *end && *end != '/'; end++);
}
ptr += 256;
}
return ret;
}
/**
* Static file system drivers registry
*/
file_t (*fsdrivers[]) (unsigned char *, char *) = {
//fsz_initrd,
mfs_initrd,
cpio_initrd,
tar_initrd,
sfs_initrd,
jamesm_initrd,
ech_initrd,
NULL
};
#undef DBG

11
lboot.S
View file

@ -1,9 +1,12 @@
// vim: et:sw=12:ts=12:sts=12 // vim: et:sw=12:ts=12:sts=12
// lboot.S: boot code for legacy BIOS boot over PXE.
.global _start .global _start
.text .text
.code16 .code16
.set PACKET_SIZE, 1024
.macro pxe_call, opcode .macro pxe_call, opcode
mov %sp, %bx mov %sp, %bx
push %ss push %ss
@ -66,7 +69,7 @@ _start: cli
push $0 push $0
push %cs push %cs
push $tx_buf push $tx_buf
push $1024 push $PACKET_SIZE
push $2 push $2
push $0 push $0
pxe_call PXE_GET_CACHED_INFO pxe_call PXE_GET_CACHED_INFO
@ -254,8 +257,8 @@ _aerr: mov $msg_aerr, %si
read_file: read_file:
.set PXE_TFTP_OPEN, 0x0020 .set PXE_TFTP_OPEN, 0x0020
push $1024 push $PACKET_SIZE
push $0x4500 push $69<<8
sub $128, %sp sub $128, %sp
mov $fn_config, %esi mov $fn_config, %esi
@ -424,7 +427,7 @@ pml4_ptr: .long 0
// Points to the end of the memory map // Points to the end of the memory map
memmap_end: .word 0 memmap_end: .word 0
tx_buf: .space 1024 tx_buf: .space PACKET_SIZE
.code64 .code64
// trampo64: Trampoline function to load long-mode segments // trampo64: Trampoline function to load long-mode segments

123
loader.c
View file

@ -1,3 +1,126 @@
#include <stdint.h>
#include <stddef.h>
// minimal set of string routines, copied from KarlOS
void *memset(void *ptr, int value, size_t num)
{
__asm__ ("rep stosb"
: "+D"(ptr), "+c"(num)
: "a"(value)
: "memory");
return ptr;
}
void *memcpy(void *restrict dest, const void *restrict src, size_t num)
{
__asm__ ("rep movsb"
: "+D"(dest), "+S"(src), "+c"(num)
:
: "memory");
return dest;
}
int memcmp(const void *ptr, const void *ptr2, size_t num)
{
unsigned char *d = (unsigned char *)ptr;
unsigned char *b = (unsigned char *)ptr2;
for (size_t i = 0; i < num; i++) {
if (d[i] != b[i]) {
return (d[i] - b[i]);
}
}
return 0;
}
size_t strlen(const char *s)
{
size_t len = 0;
while (*s != '\0') {
s++;
len++;
}
return len;
}
// Helpers from bztsrc's bootboot codebase
/**
* convert ascii octal number to binary number
*/
int octbin(unsigned char *str,int size)
{
int s=0;
unsigned char *c=str;
while(size-->0){
s*=8;
s+=*c-'0';
c++;
}
return s;
}
/**
* convert ascii hex number to binary number
*/
int hexbin(unsigned char *str, int size)
{
int v=0;
while(size-->0){
v <<= 4;
if(*str>='0' && *str<='9')
v += (int)((unsigned char)(*str)-'0');
else if(*str >= 'A' && *str <= 'F')
v += (int)((unsigned char)(*str)-'A'+10);
str++;
}
return v;
}
typedef struct {
uint8_t *ptr;
uint64_t size;
} file_t;
#include "bootboot.h"
#include "fs.h"
// ELF64
#define EI_NIDENT 16
#define EI_MAG0 0x7F
#define EI_MAG1 'E'
#define EI_MAG2 'L'
#define EI_MAG3 'F'
typedef struct {
unsigned char e_ident[EI_NIDENT];
uint16_t e_type;
uint16_t e_machine;
uint32_t e_version;
uint64_t e_entry;
uint64_t e_phoff;
uint64_t e_shoff;
uint32_t e_flags;
uint16_t e_ehsize;
uint16_t e_phentsize;
uint16_t e_phnum;
uint16_t e_shentsize;
uint16_t e_shnum;
uint16_t e_shstrndx;
} Elf64_Ehdr;
typedef struct {
uint32_t p_type;
uint32_t p_flags;
uint64_t p_offset;
uint64_t p_vaddr;
uint64_t p_paddr;
uint64_t p_filesz;
uint64_t p_memsz;
uint64_t p_align;
} Elf64_Phdr;
void void
loader_main(void) loader_main(void)
{ {