[LinuxBIOS] Complete and generic 32bit/64bit support
Jordan Crouse
jordan.crouse at amd.com
Thu Nov 22 00:14:38 CET 2007
On 21/11/07 13:37 -0800, yhlu wrote:
> On Nov 21, 2007 12:03 PM, Myles Watson <myles at pel.cs.byu.edu> wrote:
> > >
> > > On Wed, Nov 21, 2007 at 12:13:23PM -0700, Myles Watson wrote:
> > > > It makes the same changes as mentioned before, but it also uses the
> > > > correct kernel image depending on the architecture. mkelfimage
> > > > doesn't work with an x86_64 vmlinux, and with an i386 bzImage it
> > > > generates a _much_ larger elf.
>
> for x86_64 support
> there is a patch i posted several months ago.
Excellent! This should fit into buildrom very nicely.
Thanks.
Jordan
> [PATCH] mkelfImage: Take elf64 vmlinux and produce elf32
>
> change to use e_entry instead of hardcode for vmlinux
> if e_entry is not equal to paddr of fist phdr, will use paddr instead, and not switch to 64bit in convert
> otherwise will use e_entry and switch to 64bit in convert
>
> also fix the bss_size calculation.
>
> Signed-off-By: Yinghai Lu <yinghai.lu at amd.com>
>
> diff -uNr mkelfImage-2.7/linux-i386/convert.h mkelfImage-2.7.new/linux-i386/convert.h
> --- mkelfImage-2.7/linux-i386/convert.h 2006-03-17 06:08:21.000000000 -0800
> +++ mkelfImage-2.7.new/linux-i386/convert.h 2006-11-08 12:32:15.000000000 -0800
> @@ -3,6 +3,8 @@
> #define CONVERTLOC 0x10000
> #define REAL_MODE_DATA_LOC 0x20000
> #define GDTLOC 0x21000
> +#define GDT64LOC 0x22000
> +#define PGTLOC 0x23000
>
> #define DEFAULT_ROOT_DEV ((0x3<<8)| 0)
>
> @@ -18,10 +20,13 @@
> struct image_parameters {
> uint32_t convert_magic; /* a signature to verify mkelfImage was built properly */
> uint32_t gdt_size;
> + uint32_t gdt64_size;
> + uint32_t pgt_size;
> uint32_t bss_size;
> uint16_t ramdisk_flags;
> uint16_t root_dev;
> uint32_t entry;
> + uint32_t switch_64;
> uint32_t initrd_start;
> uint32_t initrd_size;
> uint8_t cmdline[CMDLINE_MAX];
> diff -uNr mkelfImage-2.7/linux-i386/convert.lds mkelfImage-2.7.new/linux-i386/convert.lds
> --- mkelfImage-2.7/linux-i386/convert.lds 2003-01-16 13:41:14.000000000 -0800
> +++ mkelfImage-2.7.new/linux-i386/convert.lds 2006-11-08 12:19:12.000000000 -0800
> @@ -27,7 +27,7 @@
> *(.bss)
> }
> _end = . ;
> - bss_size = _end - _bss;
> + bss_sizex = _end - _bss;
>
> /DISCARD/ : {
> *(.comment)
> diff -uNr mkelfImage-2.7/linux-i386/head.S mkelfImage-2.7.new/linux-i386/head.S
> --- mkelfImage-2.7/linux-i386/head.S 2003-01-24 14:48:03.000000000 -0800
> +++ mkelfImage-2.7.new/linux-i386/head.S 2006-11-08 12:19:32.000000000 -0800
> @@ -59,7 +59,7 @@
> movl $GDTLOC, %edi
> movl $(gdt_end - gdt), %ecx
> rep movsb
> -
> +
> # Linux makes stupid assumptions about the segments
> # that are already setup, so setup a new gdt & ldt
> # and then reload the segment registers.
> @@ -95,22 +95,113 @@
> # Flag to indicate we are the bootstrap processor
> xorl %ebx, %ebx
>
> + movl switch_64, %eax
> + cmp $1, %eax
> + jz switch_to_64
> +
> # Clear the unspecified registers for good measure
> xorl %eax, %eax
> xorl %ecx, %ecx
> xorl %edx, %edx
> xorl %edi, %edi
> - xorl %esp, %esp
> xorl %ebp, %ebp
> +
> + # do not clear esp, we still need to use lret later
> +
> + pushl $PROT_CODE_SEG
> + movl entry, %eax
> + pushl %eax
> +
> + lret
> +
> +switch_to_64:
> +
> + /* We need to switch to 64bit before use startup_64 entry go to kernel */
> + /*
> + * Prepare for entering 64 bit mode
> + */
> + # Move the gdt64 where Linux will not smash it during decompression
> + movl %esi, %eax # save the real mode pointer
> + movl $gdt64, %esi
> + movl $GDT64LOC, %edi
> + movl $(gdt64_end - gdt64), %ecx
> + rep movsb
> + movl %eax, %esi
> +
> + /* Load new GDT with the 64bit segments using 32bit descriptor */
> + lgdt gdt64
> +
> + /* Enable PAE mode */
> + xorl %eax, %eax
> + btsl $5, %eax
> + movl %eax, %cr4
> +
> + /*
> + * Build early 4G boot pagetable
> + */
> + /* Initialize Page tables to 0*/
> + movl $PGTLOC, %edi
> + xorl %eax, %eax
> + movl $((4096*6)/4), %ecx
> + rep stosl
> +
> + /* Build Level 4 */
> + movl $(PGTLOC + 0), %edi
> + leal 0x1007 (%edi), %eax
> + movl %eax, 0(%edi)
> +
> + /* Build Level 3 */
> + movl $(PGTLOC + 0x1000), %edi
> + leal 0x1007(%edi), %eax
> + movl $4, %ecx
> +1: movl %eax, 0x00(%edi)
> + addl $0x00001000, %eax
> + addl $8, %edi
> + decl %ecx
> + jnz 1b
> +
> + /* Build Level 2 */
> + movl $(PGTLOC + 0x2000), %edi
> + movl $0x00000183, %eax
> + movl $2048, %ecx
> +1: movl %eax, 0(%edi)
> + addl $0x00200000, %eax
> + addl $8, %edi
> + decl %ecx
> + jnz 1b
> +
> + /* Enable the boot page tables */
> + movl $PGTLOC, %eax
> + movl %eax, %cr3
> +
> + /* Enable Long mode in EFER (Extended Feature Enable Register) */
> + movl $0xc0000080, %ecx
> + rdmsr
> + btsl $8, %eax
> + wrmsr
> +
> + /* Preparing for 64bit jmp */
> + pushl $PROT_CODE_SEG
> + movl entry, %eax
> + pushl %eax
> +
> + /* Enter paged protected Mode, activating Long Mode */
> + xorl %eax, %eax
> + btsl $31, %eax
> + btsl $0, %eax
> + movl %eax, %cr0
> +
> + /*
> + * At this point we're in long mode but in 32bit compatibility mode
> + * with EFER.LME = 1, CS.L = 0, CS.D = 1 (and in turn
> + * EFER.LMA = 1). Now we want to jump in 64bit mode, to do that we use
> + * the new gdt/idt that has __KERNEL_CS with CS.L = 1.
> + */
>
> -
> - # Jump to the linux kernel
> - ljmp $ PROT_CODE_SEG , $ 0x100000
> + lret
>
>
> /* Routines to query the BIOS... */
> -
> -
> /**************************************************************************
> E820_MEMSIZE - Get a listing of memory regions
> **************************************************************************/
> @@ -409,6 +500,7 @@
> .word 0x9200 # data read/write
> .word 0x00CF # granularity = 4096, 386
> # (+5th nibble of limit)
> +
> /*
> * The layout of the per-CPU GDT under Linux:
> *
> @@ -446,7 +538,14 @@
> */
> gdt_end:
>
> -
> +gdt64:
> + .word gdt64_end - gdt64
> + .long GDT64LOC
> + .word 0
> + .quad 0x0000000000000000 /* NULL descriptor */
> + .quad 0x00af9a000000ffff /* __KERNEL_CS */
> + .quad 0x00cf92000000ffff /* __KERNEL_DS */
> +gdt64_end:
>
> .section ".trailer", "a"
> /* Constants set at build time, these are at the very end of my image */
> @@ -458,14 +557,20 @@
> .long CONVERT_MAGIC
> gdt_size:
> .long gdt_end - gdt
> +gdt64_size:
> + .long gdt64_end - gdt64
> +pgt_size:
> + .long 4096*6
> bss_size:
> - .long bss_size
> + .long bss_sizex
> ramdisk_flags:
> .word 0
> root_dev:
> .word DEFAULT_ROOT_DEV
> entry:
> .long 0
> +switch_64:
> + .long 0
> initrd_start:
> .long 0
> initrd_size:
> diff -uNr mkelfImage-2.7/linux-i386/mkelf-linux-i386.c mkelfImage-2.7.new/linux-i386/mkelf-linux-i386.c
> --- mkelfImage-2.7/linux-i386/mkelf-linux-i386.c 2006-03-17 06:08:22.000000000 -0800
> +++ mkelfImage-2.7.new/linux-i386/mkelf-linux-i386.c 2006-11-08 09:54:58.000000000 -0800
> @@ -19,13 +19,16 @@
> static void (*parse_kernel_type)(struct kernel_info *info, char *kernel_buf, size_t kernel_size);
> static void parse_bzImage_kernel(struct kernel_info *info, char *kernel_buf, size_t kernel_size);
> static void parse_elf32_kernel(struct kernel_info *info, char *kernel_buf, size_t kernel_size);
> +static void parse_elf64_kernel(struct kernel_info *info, char *kernel_buf, size_t kernel_size);
> +
> +char *vmlinux_x86_64_probe(char *kernel_buf, off_t kernel_size);
>
> char *vmlinux_i386_probe(char *kernel_buf, off_t kernel_size)
> {
> Elf32_Ehdr *ehdr;
> Elf32_Phdr *phdr;
> int i;
> - int hdr1, hdr2;
> + int phdrs;
> ehdr = (Elf32_Ehdr *)kernel_buf;
> if (
> (ehdr->e_ident[EI_MAG0] != ELFMAG0) ||
> @@ -35,7 +38,8 @@
> return "No ELF signature found on kernel\n";
> }
> if (ehdr->e_ident[EI_CLASS] != ELFCLASS32) {
> - return "Not a 32bit ELF kernel\n";
> + return vmlinux_x86_64_probe(kernel_buf, kernel_size);
> +// return "Not a 32bit ELF kernel\n";
> }
> if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
> return "Not a little endian ELF kernel\n";
> @@ -54,27 +58,64 @@
> return "Kernel uses bad program header size.\n";
> }
> phdr = (Elf32_Phdr *)(kernel_buf + le32_to_cpu(ehdr->e_phoff));
> - hdr1 = hdr2 = -1;
> - for(i = 0; i < le32_to_cpu(ehdr->e_phnum); i++) {
> + phdrs = 0;
> + for(i = 0; i < le16_to_cpu(ehdr->e_phnum); i++) {
> if (le32_to_cpu(phdr[i].p_type) != PT_LOAD)
> continue;
> - if (((hdr1 != -1) &&
> - ((le32_to_cpu(phdr[hdr1].p_paddr) & 0xfffffff) != 0x100000)) ||
> - (hdr2 != -1)) {
> - return "Too many PT_LOAD segments to be a linux kernel\n";
> - }
> - if (hdr1 == -1) {
> - hdr1 = i;
> - } else {
> - hdr2 = i;
> - }
> + phdrs++;
> }
> - if (hdr1 == -1) {
> + if (phdrs == 0) {
> return "No PT_LOAD segments!\n";
> }
> parse_kernel_type = parse_elf32_kernel;
> return 0;
> }
> +char *vmlinux_x86_64_probe(char *kernel_buf, off_t kernel_size)
> +{
> + Elf64_Ehdr *ehdr;
> + Elf64_Phdr *phdr;
> + int i;
> + int phdrs = 0;
> + ehdr = (Elf64_Ehdr *)kernel_buf;
> + if (
> + (ehdr->e_ident[EI_MAG0] != ELFMAG0) ||
> + (ehdr->e_ident[EI_MAG1] != ELFMAG1) ||
> + (ehdr->e_ident[EI_MAG2] != ELFMAG2) ||
> + (ehdr->e_ident[EI_MAG3] != ELFMAG3)) {
> + return "No ELF signature found on kernel\n";
> + }
> + if (ehdr->e_ident[EI_CLASS] != ELFCLASS64) {
> + return "Not a 64bit ELF kernel\n";
> + }
> + if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
> + return "Not a little endian ELF kernel\n";
> + }
> + if (le16_to_cpu(ehdr->e_type) != ET_EXEC) {
> + return "Not an executable kernel\n";
> + }
> + if (le16_to_cpu(ehdr->e_machine) != EM_X86_64) {
> + return "Not an x86_64 kernel\n";
> + }
> + if ( (ehdr->e_ident[EI_VERSION] != EV_CURRENT) ||
> + (le32_to_cpu(ehdr->e_version) != EV_CURRENT)) {
> + return "Kernel not using ELF version 1.\n";
> + }
> + if (le16_to_cpu(ehdr->e_phentsize) != sizeof(*phdr)) {
> + return "Kernel uses bad program header size.\n";
> + }
> + phdr = (Elf64_Phdr *)(kernel_buf + le64_to_cpu(ehdr->e_phoff));
> + phdrs = 0;
> + for(i = 0; i < le16_to_cpu(ehdr->e_phnum); i++) {
> + if (le32_to_cpu(phdr[i].p_type) != PT_LOAD)
> + continue;
> + phdrs++;
> + }
> + if (phdrs == 0) {
> + return "No PT_LOAD segments!\n";
> + }
> + parse_kernel_type = parse_elf64_kernel;
> + return 0;
> +}
>
> char *bzImage_i386_probe(char *kernel_buf, off_t kernel_size)
> {
> @@ -118,17 +159,14 @@
>
> struct kernel_info
> {
> - void *kernel;
> - size_t filesz;
> - size_t memsz;
> - size_t paddr;
> - size_t vaddr;
> - void *kernel2;
> - size_t filesz2;
> - size_t memsz2;
> - size_t paddr2;
> - size_t vaddr2;
> + int phdrs;
> + void *kernel[4];
> + size_t filesz[4];
> + size_t memsz[4];
> + size_t paddr[4];
> + size_t vaddr[4];
> size_t entry;
> + size_t switch_64;
> char *version;
> };
>
> @@ -137,43 +175,68 @@
> Elf32_Ehdr *ehdr;
> Elf32_Phdr *phdr;
> int i;
> - int hdr1, hdr2;
> + int phdrs;
> ehdr = (Elf32_Ehdr *)kernel_buf;
> phdr = (Elf32_Phdr *)(kernel_buf + ehdr->e_phoff);
> - hdr1 = hdr2 = -1;
> + phdrs = 0;
> for(i = 0; i < le16_to_cpu(ehdr->e_phnum); i++) {
> if (le32_to_cpu(phdr[i].p_type) != PT_LOAD)
> continue;
> - if (hdr2 != -1) {
> - die("Too many PT_LOAD segments to be a linux kernel\n");
> - }
> - if (hdr1 == -1) {
> - hdr1 = i;
> - } else {
> - hdr2 = i;
> - }
> - }
> - if (hdr1 == -1) {
> - die("No PT_LOAD segments!\n");
> + info->kernel[phdrs] = kernel_buf + le32_to_cpu(phdr[i].p_offset);
> + info->filesz[phdrs] = le32_to_cpu(phdr[i].p_filesz);
> + info->memsz[phdrs] = le32_to_cpu(phdr[i].p_memsz);
> + info->paddr[phdrs] = le32_to_cpu(phdr[i].p_paddr) & 0xfffffff;
> + info->vaddr[phdrs] = le32_to_cpu(phdr[i].p_vaddr);
> + phdrs++;
> }
> - info->kernel = kernel_buf + le32_to_cpu(phdr[hdr1].p_offset);
> - info->filesz = le32_to_cpu(phdr[hdr1].p_filesz);
> - info->memsz = le32_to_cpu(phdr[hdr1].p_memsz);
> - info->paddr = le32_to_cpu(phdr[hdr1].p_paddr) & 0xfffffff;
> - info->vaddr = le32_to_cpu(phdr[hdr1].p_vaddr);
> -
> - if (hdr2 != -1) {
> - info->kernel2 = kernel_buf + le32_to_cpu(phdr[hdr2].p_offset);
> - info->filesz2 = le32_to_cpu(phdr[hdr2].p_filesz);
> - info->memsz2 = le32_to_cpu(phdr[hdr2].p_memsz);
> - info->paddr2 = le32_to_cpu(phdr[hdr2].p_paddr) & 0xfffffff;
> - info->vaddr2 = le32_to_cpu(phdr[hdr2].p_vaddr);
> +
> + if(!phdrs)
> + die("We need at least one phdr\n");
> +
> + info->phdrs = phdrs;
> + info->entry = le32_to_cpu(ehdr->e_entry);
> + info->switch_64 = 0; //not convert from elf64
> + info->version = "unknown";
> +}
> +
> +static void parse_elf64_kernel(struct kernel_info *info, char *kernel_buf, size_t kernel_size)
> +{
> + Elf64_Ehdr *ehdr;
> + Elf64_Phdr *phdr;
> + int i;
> + int phdrs;
> + ehdr = (Elf64_Ehdr *)kernel_buf;
> + phdr = (Elf64_Phdr *)(kernel_buf + le64_to_cpu(ehdr->e_phoff));
> +
> + phdrs = 0;
> + for(i = 0; i < le16_to_cpu(ehdr->e_phnum); i++) {
> + if (le32_to_cpu(phdr[i].p_type) != PT_LOAD)
> + continue;
> + info->kernel[phdrs] = kernel_buf + le64_to_cpu(phdr[i].p_offset);
> + info->filesz[phdrs] = le64_to_cpu(phdr[i].p_filesz);
> + info->memsz[phdrs] = le64_to_cpu(phdr[i].p_memsz);
> + info->paddr[phdrs] = le64_to_cpu(phdr[i].p_paddr) & 0xffffff;
> + info->vaddr[phdrs] = le64_to_cpu(phdr[i].p_vaddr);
> + phdrs++;
> }
> +
> + if(!phdrs)
> + die("We need at least one phdr\n");
>
> - info->entry = 0x100000;
> - info->version = "unknown";
> + info->phdrs = phdrs;
> + info->entry = le64_to_cpu(ehdr->e_entry);
> +#if 0
> + if (info->entry != info->paddr[0]) {
> + info->entry = info->paddr[0]; // we still have startup_32 there
> + info->switch_64 = 0; //not convert from elf64
> + } else
> +#endif
> + info->switch_64 = 1; //convert from elf64
> +
> + info->version = "unknown";
> }
>
> +
> static void parse_bzImage_kernel(struct kernel_info *info, char *kernel_buf, size_t kernel_size)
> {
> struct x86_linux_header *hdr;
> @@ -186,12 +249,14 @@
> }
> offset = 512 + (512 *setup_sects);
>
> - info->kernel = kernel_buf + offset;
> - info->filesz = kernel_size - offset;
> - info->memsz = 0x700000;
> - info->paddr = 0x100000;
> - info->vaddr = 0x100000;
> - info->entry = info->paddr;
> + info->kernel[0] = kernel_buf + offset;
> + info->filesz[0] = kernel_size - offset;
> + info->memsz[0] = 0x700000;
> + info->paddr[0] = 0x100000;
> + info->vaddr[0] = 0x100000;
> + info->phdrs = 1;
> + info->entry = info->paddr[0];
> + info->switch_64 = 0; //not convert from elf64, even later bzImage become elf64, it still includes startup_32
> info->version = kernel_buf + 512 + le16_to_cpu(hdr->kver_addr);
> }
>
> @@ -237,6 +302,7 @@
> struct kernel_info kinfo;
> struct image_parameters *params;
> int index;
> + int i;
>
> int opt;
> static const struct option options[] = {
> @@ -310,7 +376,7 @@
>
> /* Add a program header for the note section */
> index = 4;
> - index += kinfo.kernel2 ? 1:0;
> + index += (kinfo.phdrs - 1);
> index += ramdisk_size ? 1:0;
> phdr = add_program_headers(ehdr, index);
>
> @@ -328,23 +394,24 @@
> phdr[2].p_paddr = REAL_MODE_DATA_LOC;
> phdr[2].p_vaddr = REAL_MODE_DATA_LOC;
> phdr[2].p_filesz = 0;
> - phdr[2].p_memsz = (GDTLOC - REAL_MODE_DATA_LOC) + params->gdt_size;
> + if(!kinfo.switch_64)
> + phdr[2].p_memsz = (GDTLOC - REAL_MODE_DATA_LOC) + params->gdt_size;
> + else
> + phdr[2].p_memsz = (PGTLOC - REAL_MODE_DATA_LOC) + params->pgt_size;
> phdr[2].p_data = 0;
>
> - phdr[3].p_paddr = kinfo.paddr;
> - phdr[3].p_vaddr = kinfo.vaddr;
> - phdr[3].p_filesz = kinfo.filesz;
> - phdr[3].p_memsz = kinfo.memsz;
> - phdr[3].p_data = kinfo.kernel;
> + if( (phdr[1].p_paddr + phdr[1].p_memsz) > phdr[2].p_paddr) {
> + die("Internal error: need to increase REAL_MODE_DATA_LOC !\n");
> + }
>
> - index = 4;
> + index = 3;
> /* Put the second kernel frament if present */
> - if (kinfo.kernel2) {
> - phdr[index].p_paddr = kinfo.paddr2;
> - phdr[index].p_vaddr = kinfo.vaddr2;
> - phdr[index].p_filesz = kinfo.filesz2;
> - phdr[index].p_memsz = kinfo.memsz2;
> - phdr[index].p_data = kinfo.kernel2;
> + for(i=0;i<kinfo.phdrs;i++) {
> + phdr[index].p_paddr = kinfo.paddr[i];
> + phdr[index].p_vaddr = kinfo.vaddr[i];
> + phdr[index].p_filesz = kinfo.filesz[i];
> + phdr[index].p_memsz = kinfo.memsz[i];
> + phdr[index].p_data = kinfo.kernel[i];
> index++;
> }
>
> @@ -352,6 +419,10 @@
> */
> params->initrd_start = params->initrd_size = 0;
> if (ramdisk_size) {
> + if( (phdr[index-1].p_paddr + phdr[index-1].p_memsz) > ramdisk_base) {
> + die("need to increase increase ramdisk_base !\n");
> + }
> +
> phdr[index].p_paddr = ramdisk_base;
> phdr[index].p_vaddr = ramdisk_base;
> phdr[index].p_filesz = ramdisk_size;
> @@ -364,6 +435,7 @@
>
> /* Set the start location */
> params->entry = kinfo.entry;
> + params->switch_64 = kinfo.switch_64;
> ehdr->e_entry = phdr[1].p_paddr;
>
> /* Setup the elf notes */
> diff -uNr mkelfImage-2.7/linux-ia64/mkelf-linux-ia64.c mkelfImage-2.7.new/linux-ia64/mkelf-linux-ia64.c
> --- mkelfImage-2.7/linux-ia64/mkelf-linux-ia64.c 2006-03-17 10:09:16.000000000 -0800
> +++ mkelfImage-2.7.new/linux-ia64/mkelf-linux-ia64.c 2006-11-07 18:14:27.000000000 -0800
> @@ -81,7 +81,7 @@
> phdr = (Elf64_Phdr *)(kernel_buf + le64_to_cpu(ehdr->e_phoff));
> phdrs = 0;
> for(i = 0; i < le16_to_cpu(ehdr->e_phnum); i++) {
> - if (le16_to_cpu(phdr[i].p_type) != PT_LOAD)
> + if (le32_to_cpu(phdr[i].p_type) != PT_LOAD)
> continue;
> phdrs++;
> }
> --
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--
Jordan Crouse
Systems Software Development Engineer
Advanced Micro Devices, Inc.
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