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mirror of https://git.FreeBSD.org/src.git synced 2024-12-14 10:09:48 +00:00

[PowerPC] kernel ifunc support for powerpc*, fix ppc64 relocation oddities.

This is a general cleanup of the relocatable kernel support on powerpc,
needed to enable kernel ifuncs.

 * Fix some relocatable issues in the kernel linker, and change to using
   a RELOCATABLE_KERNEL #define instead of #ifdef __powerpc__ for parts that
   other platforms can use in the future if they wish to have ET_DYN kernels.

 * Get rid of the DB_STOFFS hack now that the kernel is relocated to the DMAP
   properly across the board on powerpc64.

 * Add powerpc64 and powerpc32 ifunc functionality.

 * Allow AIM64 virtual mode OF kernels to run from the DMAP like other AIM64
   by implementing a virtual mode restart. This fixes the runtime address on
   PowerMac G5.

 * Fix symbol relocation problems on post-relocation kernels by relocating
   the symbol table.

 * Add an undocumented method for supplying kernel symbols on powernv and
   other powerpc machines using linux-style kernel/initrd loading -- If
   you pass the kernel in as the initrd as well, the copy resident in initrd
   will be used as a source for symbols when initializing the debugger.
   This method is subject to removal once we have a better way of doing this.

Approved by:	jhibbits
Relnotes:	yes
Sponsored by:	Tag1 Consulting, Inc.
Differential Revision:	https://reviews.freebsd.org/D23156
This commit is contained in:
Brandon Bergren 2020-05-07 19:32:49 +00:00
parent f8519228d1
commit 9411e24df3
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=360794
13 changed files with 367 additions and 35 deletions

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@ -161,9 +161,9 @@ LDFLAGS+= --build-id=sha1
.endif
.if (${MACHINE_CPUARCH} == "aarch64" || ${MACHINE_CPUARCH} == "amd64" || \
${MACHINE_CPUARCH} == "i386") && \
${MACHINE_CPUARCH} == "i386" || ${MACHINE} == "powerpc") && \
defined(LINKER_FEATURES) && ${LINKER_FEATURES:Mifunc} == ""
.error amd64/arm64/i386 kernel requires linker ifunc support
.error amd64/arm64/i386/ppc* kernel requires linker ifunc support
.endif
.if ${MACHINE_CPUARCH} == "amd64"
LDFLAGS+= -z max-page-size=2097152

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@ -6,6 +6,11 @@ OUTPUT_ARCH(powerpc)
ENTRY(__start)
SEARCH_DIR(/usr/lib);
PROVIDE (__stack = 0);
PHDRS
{
kernel PT_LOAD;
dynamic PT_DYNAMIC;
}
SECTIONS
{
/* Read-only sections, merged into text segment: */
@ -21,7 +26,7 @@ SECTIONS
/* .gnu.warning sections are handled specially by elf32.em. */
*(.gnu.warning)
*(.gnu.linkonce.t*)
} =0
} :kernel =0
_etext = .;
PROVIDE (etext = .);
@ -77,7 +82,7 @@ SECTIONS
.got.plt : { *(.got.plt) }
.dynamic : { *(.dynamic) }
.dynamic : { *(.dynamic) } :kernel :dynamic
/* Put .ctors and .dtors next to the .got2 section, so that the pointers
get relocated with -mrelocatable. Also put in the .fixup pointers.
The current compiler no longer needs this, but keep it around for 2.7.2 */
@ -96,7 +101,7 @@ SECTIONS
/* We want the small data sections together, so single-instruction offsets
can access them all, and initialized data all before uninitialized, so
we can shorten the on-disk segment size. */
.sdata : { *(.sdata) }
.sdata : { *(.sdata) } :kernel
_edata = .;
PROVIDE (edata = .);
.sbss :

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@ -8,15 +8,15 @@ SEARCH_DIR(/usr/lib);
PROVIDE (__stack = 0);
PHDRS
{
text PT_LOAD ;
dynamic PT_DYNAMIC ;
kernel PT_LOAD;
dynamic PT_DYNAMIC;
}
SECTIONS
{
/* Low-address wrapper for bootloaders (kexec/kboot) that can't parse ELF */
. = kernbase - 0x100;
.kboot : { *(.text.kboot) } :text
.kboot : { *(.text.kboot) } :kernel
/* Read-only sections, merged into text segment: */
. = kernbase;
@ -106,7 +106,7 @@ SECTIONS
.got : ALIGN(8) { __tocbase = .; *(.got) }
.toc : ALIGN(8) { *(.toc) }
.dynamic : { *(.dynamic) } :text :dynamic
.dynamic : { *(.dynamic) } :kernel :dynamic
/* Put .ctors and .dtors next to the .got2 section, so that the pointers
get relocated with -mrelocatable. Also put in the .fixup pointers.
The current compiler no longer needs this, but keep it around for 2.7.2 */
@ -125,7 +125,7 @@ SECTIONS
/* We want the small data sections together, so single-instruction offsets
can access them all, and initialized data all before uninitialized, so
we can shorten the on-disk segment size. */
.sdata : { *(.sdata) }
.sdata : { *(.sdata) } :kernel
_edata = .;
PROVIDE (edata = .);
.sbss :

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@ -6,6 +6,11 @@ OUTPUT_ARCH(powerpc)
ENTRY(__start)
SEARCH_DIR(/usr/lib);
PROVIDE (__stack = 0);
PHDRS
{
kernel PT_LOAD;
dynamic PT_DYNAMIC;
}
SECTIONS
{
/* Read-only sections, merged into text segment: */
@ -21,7 +26,7 @@ SECTIONS
/* .gnu.warning sections are handled specially by elf32.em. */
*(.gnu.warning)
*(.gnu.linkonce.t*)
} =0
} :kernel =0
_etext = .;
PROVIDE (etext = .);
@ -78,7 +83,7 @@ SECTIONS
.got.plt : { *(.got.plt) }
.dynamic : { *(.dynamic) }
.dynamic : { *(.dynamic) } :kernel :dynamic
/* Put .ctors and .dtors next to the .got2 section, so that the pointers
get relocated with -mrelocatable. Also put in the .fixup pointers.
The current compiler no longer needs this, but keep it around for 2.7.2 */
@ -97,7 +102,7 @@ SECTIONS
/* We want the small data sections together, so single-instruction offsets
can access them all, and initialized data all before uninitialized, so
we can shorten the on-disk segment size. */
.sdata : { *(.sdata) }
.sdata : { *(.sdata) } :kernel
_edata = .;
PROVIDE (edata = .);
.sbss :

View File

@ -388,7 +388,9 @@ link_elf_link_common_finish(linker_file_t lf)
return (0);
}
#ifdef RELOCATABLE_KERNEL
extern vm_offset_t __startkernel, __endkernel;
#endif
static unsigned long kern_relbase = KERNBASE;
@ -424,7 +426,7 @@ link_elf_init(void* arg)
ef = (elf_file_t) linker_kernel_file;
ef->preloaded = 1;
#ifdef __powerpc__
#ifdef RELOCATABLE_KERNEL
ef->address = (caddr_t) (__startkernel - KERNBASE);
#else
ef->address = 0;
@ -436,7 +438,7 @@ link_elf_init(void* arg)
if (dp != NULL)
parse_dynamic(ef);
#ifdef __powerpc__
#ifdef RELOCATABLE_KERNEL
linker_kernel_file->address = (caddr_t)__startkernel;
linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel);
kern_relbase = (unsigned long)__startkernel;
@ -1860,7 +1862,7 @@ link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
return (ef->ddbstrcnt);
}
#if defined(__i386__) || defined(__amd64__) || defined(__aarch64__)
#if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) || defined(__powerpc__)
/*
* Use this lookup routine when performing relocations early during boot.
* The generic lookup routine depends on kobj, which is not initialized
@ -1896,8 +1898,14 @@ link_elf_ireloc(caddr_t kmdp)
ef->modptr = kmdp;
ef->dynamic = (Elf_Dyn *)&_DYNAMIC;
parse_dynamic(ef);
#ifdef RELOCATABLE_KERNEL
ef->address = (caddr_t) (__startkernel - KERNBASE);
#else
ef->address = 0;
#endif
parse_dynamic(ef);
link_elf_preload_parse_symbols(ef);
relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true);
}

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@ -161,6 +161,7 @@ extern void *dsmisstrap, *dsmisssize;
extern void *ap_pcpu;
extern void __restartkernel(vm_offset_t, vm_offset_t, vm_offset_t, void *, uint32_t, register_t offset, register_t msr);
extern void __restartkernel_virtual(vm_offset_t, vm_offset_t, vm_offset_t, void *, uint32_t, register_t offset, register_t msr);
void aim_early_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry,
void *mdp, uint32_t mdp_cookie);
@ -184,13 +185,22 @@ aim_early_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
#ifdef __powerpc64__
/*
* If in real mode, relocate to high memory so that the kernel
* Relocate to high memory so that the kernel
* can execute from the direct map.
*
* If we are in virtual mode already, use a special entry point
* that sets up a temporary DMAP to execute from until we can
* properly set up the MMU.
*/
if (!(mfmsr() & PSL_DR) &&
(vm_offset_t)&aim_early_init < DMAP_BASE_ADDRESS)
__restartkernel(fdt, 0, ofentry, mdp, mdp_cookie,
DMAP_BASE_ADDRESS, mfmsr());
if ((vm_offset_t)&aim_early_init < DMAP_BASE_ADDRESS) {
if (mfmsr() & PSL_DR) {
__restartkernel_virtual(fdt, 0, ofentry, mdp,
mdp_cookie, DMAP_BASE_ADDRESS, mfmsr());
} else {
__restartkernel(fdt, 0, ofentry, mdp, mdp_cookie,
DMAP_BASE_ADDRESS, mfmsr());
}
}
#endif
/* Various very early CPU fix ups */

View File

@ -200,6 +200,57 @@ ASENTRY_NOPROF(__start)
/* Unreachable */
b .
ASENTRY_NOPROF(__restartkernel_virtual)
/*
* When coming in via this entry point, we need to alter the SLB to
* shadow the segment register emulation entries in DMAP space.
* We need to do this dance because we are running with virtual-mode
* OpenFirmware and have not yet taken over the MMU.
*
* Assumptions:
* 1) The kernel is currently identity-mapped.
* 2) We are currently executing at an address compatible with
* real mode.
* 3) The first 16 SLB entries are emulating SRs.
* 4) The rest of the SLB is not in use.
* 5) OpenFirmware is not manipulating the SLB at runtime.
* 6) We are running on 64-bit AIM.
*
* Tested on a G5.
*/
mfmsr %r14
/* Switch to real mode because we are about to mess with the SLB. */
andi. %r14, %r14, ~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l
mtmsr %r14
isync
/* Prepare variables for later use. */
li %r14, 0
li %r18, 0
oris %r18, %r18, 0xc000
sldi %r18, %r18, 32 /* r18: 0xc000000000000000 */
1:
/*
* Loop over the first 16 SLB entries.
* Offset the SLBE into the DMAP, add 16 to the index, and write
* it back to the SLB.
*/
/* XXX add more safety checks */
slbmfev %r15, %r14
slbmfee %r16, %r14
or %r16, %r16, %r14 /* index is 0-15 */
ori %r16, %r16, 0x10 /* add 16 to index. */
or %r16, %r16, %r18 /* SLBE DMAP offset */
rldicr %r17, %r16, 0, 37 /* Invalidation SLBE */
isync
slbie %r17
/* isync */
slbmte %r15, %r16
isync
addi %r14, %r14, 1
cmpdi %r14, 16
blt 1b
ASENTRY_NOPROF(__restartkernel)
/*
* r3-r7: arguments to go to __start

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@ -85,8 +85,4 @@ typedef intptr_t db_expr_t; /* expression - signed */
#define inst_load(ins) 0
#define inst_store(ins) 0
#ifdef __powerpc64__
#define DB_STOFFS(offs) ((offs) & ~DMAP_BASE_ADDRESS)
#endif
#endif /* _POWERPC_DB_MACHDEP_H_ */

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@ -109,6 +109,8 @@
#define MAXPAGESIZES 1 /* maximum number of supported page sizes */
#define RELOCATABLE_KERNEL 1 /* kernel may relocate during startup */
#ifndef KSTACK_PAGES
#ifdef __powerpc64__
#define KSTACK_PAGES 8 /* includes pcb */

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@ -36,6 +36,8 @@ __FBSDID("$FreeBSD$");
#include <vm/pmap.h>
#include <machine/bus.h>
#include <machine/elf.h>
#include <machine/param.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
@ -58,6 +60,8 @@ ofw_initrd_probe_and_attach(void *junk)
vm_paddr_t start, end;
pcell_t cell[2];
ssize_t size;
u_char *taste;
Elf_Ehdr ehdr;
if (!hw_direct_map)
return;
@ -91,7 +95,15 @@ ofw_initrd_probe_and_attach(void *junk)
}
if (end - start > 0) {
mfs_root = (u_char *) PHYS_TO_DMAP(start);
taste = (u_char*) PHYS_TO_DMAP(start);
memcpy(&ehdr, taste, sizeof(ehdr));
if (IS_ELF(ehdr)) {
printf("ofw_initrd: initrd is kernel image!\n");
return;
}
mfs_root = taste;
mfs_root_size = end - start;
printf("ofw_initrd: initrd loaded at 0x%08lx-0x%08lx\n",
start, end);

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@ -221,10 +221,10 @@ elf32_dump_thread(struct thread *td, void *dst, size_t *off)
#ifndef __powerpc64__
bool
elf_is_ifunc_reloc(Elf_Size r_info __unused)
elf_is_ifunc_reloc(Elf_Size r_info)
{
return (false);
return (ELF_R_TYPE(r_info) == R_PPC_IRELATIVE);
}
/* Process one elf relocation with addend. */
@ -235,7 +235,7 @@ elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
Elf_Addr *where;
Elf_Half *hwhere;
Elf_Addr addr;
Elf_Addr addend;
Elf_Addr addend, val;
Elf_Word rtype, symidx;
const Elf_Rela *rela;
int error;
@ -317,6 +317,13 @@ elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
*where = elf_relocaddr(lf, addr + addend);
break;
case R_PPC_IRELATIVE:
addr = relocbase + addend;
val = ((Elf32_Addr (*)(void))addr)();
if (*where != val)
*where = val;
break;
default:
printf("kldload: unexpected relocation type %d\n",
(int) rtype);

View File

@ -282,10 +282,10 @@ elf64_dump_thread(struct thread *td, void *dst, size_t *off)
}
bool
elf_is_ifunc_reloc(Elf_Size r_info __unused)
elf_is_ifunc_reloc(Elf_Size r_info)
{
return (false);
return (ELF_R_TYPE(r_info) == R_PPC_IRELATIVE);
}
/* Process one elf relocation with addend. */
@ -295,7 +295,7 @@ elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
{
Elf_Addr *where;
Elf_Addr addr;
Elf_Addr addend;
Elf_Addr addend, val;
Elf_Word rtype, symidx;
const Elf_Rela *rela;
int error;
@ -342,6 +342,13 @@ elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
__asm __volatile("dcbst 0,%0; sync" :: "r"(where) : "memory");
break;
case R_PPC_IRELATIVE:
addr = relocbase + addend;
val = ((Elf64_Addr (*)(void))addr)();
if (*where != val)
*where = val;
break;
default:
printf("kldload: unexpected relocation type %d\n",
(int) rtype);

View File

@ -113,6 +113,7 @@ __FBSDID("$FreeBSD$");
#include <machine/elf.h>
#include <machine/fpu.h>
#include <machine/hid.h>
#include <machine/ifunc.h>
#include <machine/kdb.h>
#include <machine/md_var.h>
#include <machine/metadata.h>
@ -161,6 +162,8 @@ SYSCTL_INT(_machdep, CPU_CACHELINE, cacheline_size,
uintptr_t powerpc_init(vm_offset_t, vm_offset_t, vm_offset_t, void *,
uint32_t);
static void fake_preload_metadata(void);
long Maxmem = 0;
long realmem = 0;
@ -246,6 +249,11 @@ void aim_early_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry,
void aim_cpu_init(vm_offset_t toc);
void booke_cpu_init(void);
#ifdef DDB
static void load_external_symtab(void);
static void displace_symbol_table(vm_offset_t, vm_offset_t, vm_offset_t);
#endif
uintptr_t
powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
uint32_t mdp_cookie)
@ -254,10 +262,13 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
struct cpuref bsp;
vm_offset_t startkernel, endkernel;
char *env;
void *kmdp = NULL;
bool ofw_bootargs = false;
bool symbols_provided = false;
#ifdef DDB
vm_offset_t ksym_start;
vm_offset_t ksym_end;
vm_offset_t ksym_sz;
#endif
/* First guess at start/end kernel positions */
@ -286,16 +297,30 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
aim_early_init(fdt, toc, ofentry, mdp, mdp_cookie);
#endif
/*
* At this point, we are executing in our correct memory space.
* Book-E started there, and AIM has done an rfi and restarted
* execution from _start.
*
* We may still be in real mode, however. If we are running out of
* the direct map on 64 bit, this is possible to do.
*/
/*
* Parse metadata if present and fetch parameters. Must be done
* before console is inited so cninit gets the right value of
* boothowto.
*/
if (mdp != NULL) {
void *kmdp = NULL;
/*
* Starting up from loader.
*
* Full metadata has been provided, but we need to figure
* out the correct address to relocate it to.
*/
char *envp = NULL;
uintptr_t md_offset = 0;
vm_paddr_t kernelendphys;
vm_paddr_t kernelstartphys, kernelendphys;
#ifdef AIM
if ((uintptr_t)&powerpc_init > DMAP_BASE_ADDRESS)
@ -306,6 +331,7 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
preload_metadata = mdp;
if (md_offset > 0) {
/* Translate phys offset into DMAP offset. */
preload_metadata += md_offset;
preload_bootstrap_relocate(md_offset);
}
@ -321,6 +347,9 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
if (fdt != 0)
fdt += md_offset;
}
kernelstartphys = MD_FETCH(kmdp, MODINFO_ADDR,
vm_offset_t);
/* kernelstartphys is already relocated. */
kernelendphys = MD_FETCH(kmdp, MODINFOMD_KERNEND,
vm_offset_t);
if (kernelendphys != 0)
@ -329,13 +358,35 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
#ifdef DDB
ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
ksym_sz = *(Elf_Size*)ksym_start;
/*
* Loader already handled displacing to the load
* address, but we still need to displace it to the
* DMAP.
*/
displace_symbol_table(
(vm_offset_t)(ksym_start + sizeof(Elf_Size)),
ksym_sz, md_offset);
db_fetch_ksymtab(ksym_start, ksym_end);
symbols_provided = true;
#endif
}
} else {
/*
* Self-loading kernel, we have to fake up metadata.
*
* Since we are creating the metadata from the final
* memory space, we don't need to call
* preload_boostrap_relocate().
*/
fake_preload_metadata();
kmdp = preload_search_by_type("elf kernel");
init_static_kenv(init_kenv, sizeof(init_kenv));
ofw_bootargs = true;
}
/* Store boot environment state */
OF_initial_setup((void *)fdt, NULL, (int (*)(void *))ofentry);
@ -365,6 +416,11 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
*/
OF_bootstrap();
#ifdef DDB
if (!symbols_provided && hw_direct_map)
load_external_symtab();
#endif
if (ofw_bootargs)
ofw_parse_bootargs();
@ -412,6 +468,7 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
*/
pmap_bootstrap(startkernel, endkernel);
mtmsr(psl_kernset & ~PSL_EE);
link_elf_ireloc(kmdp);
/*
* Initialize params/tunables that are derived from memsize
@ -449,6 +506,178 @@ powerpc_init(vm_offset_t fdt, vm_offset_t toc, vm_offset_t ofentry, void *mdp,
(sizeof(struct callframe) - 3*sizeof(register_t))) & ~15UL);
}
#ifdef DDB
/*
* XXX Figure out where to move this.
*/
static void
displace_symbol_table(vm_offset_t ksym_start,
vm_offset_t ksym_sz, vm_offset_t displacement) {
Elf_Sym *sym;
/*
* Relocate the symbol table to our final load address.
*/
for (sym = (Elf_Sym *)ksym_start;
(vm_paddr_t)sym < (ksym_start + ksym_sz);
sym++) {
if (sym->st_name == 0 ||
sym->st_shndx == SHN_UNDEF ||
sym->st_value == 0)
continue;
if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT &&
ELF_ST_TYPE(sym->st_info) != STT_FUNC &&
ELF_ST_TYPE(sym->st_info) != STT_NOTYPE)
continue;
/* Skip relocating any implausible symbols */
if (sym->st_value > KERNBASE)
sym->st_value += displacement;
}
}
/*
* On powernv, we might not have symbols loaded via loader. However, if the
* user passed the kernel in as the initrd as well, we can manually load it
* via reinterpreting the initrd copy of the kernel.
*/
static void
load_external_symtab(void) {
phandle_t chosen;
vm_paddr_t start, end;
pcell_t cell[2];
ssize_t size;
u_char *kernelimg;
int i;
Elf_Ehdr *ehdr;
Elf_Phdr *phdr;
Elf_Shdr *shdr;
vm_offset_t ksym_start, ksym_sz, kstr_start, kstr_sz;
if (!hw_direct_map)
return;
chosen = OF_finddevice("/chosen");
if (chosen <= 0)
return;
if (!OF_hasprop(chosen, "linux,initrd-start") ||
!OF_hasprop(chosen, "linux,initrd-end"))
return;
size = OF_getencprop(chosen, "linux,initrd-start", cell, sizeof(cell));
if (size == 4)
start = cell[0];
else if (size == 8)
start = (uint64_t)cell[0] << 32 | cell[1];
else
return;
size = OF_getencprop(chosen, "linux,initrd-end", cell, sizeof(cell));
if (size == 4)
end = cell[0];
else if (size == 8)
end = (uint64_t)cell[0] << 32 | cell[1];
else
return;
if (!(end - start > 0))
return;
kernelimg = (u_char *) PHYS_TO_DMAP(start);
ehdr = (Elf_Ehdr *)kernelimg;
if (!IS_ELF(*ehdr))
return;
phdr = (Elf_Phdr *)(kernelimg + ehdr->e_phoff);
shdr = (Elf_Shdr *)(kernelimg + ehdr->e_shoff);
ksym_start = 0;
ksym_sz = 0;
kstr_start = 0;
kstr_sz = 0;
for (i = 0; i < ehdr->e_shnum; i++) {
if (shdr[i].sh_type == SHT_SYMTAB) {
ksym_start = (vm_offset_t)(kernelimg +
shdr[i].sh_offset);
ksym_sz = (vm_offset_t)(shdr[i].sh_size);
kstr_start = (vm_offset_t)(kernelimg +
shdr[shdr[i].sh_link].sh_offset);
kstr_sz = (vm_offset_t)
(shdr[shdr[i].sh_link].sh_size);
}
}
if (ksym_start != 0 && kstr_start != 0 && ksym_sz != 0 &&
kstr_sz != 0 && ksym_start < kstr_start) {
displace_symbol_table(ksym_start, ksym_sz,
(__startkernel - KERNBASE));
ksymtab = ksym_start;
ksymtab_size = ksym_sz;
kstrtab = kstr_start;
}
};
#endif
/*
* When not being loaded from loader, we need to create our own metadata
* so we can interact with the kernel linker.
*/
static void
fake_preload_metadata(void) {
/* We depend on dword alignment here. */
static uint32_t fake_preload[36] __aligned(8);
int i = 0;
fake_preload[i++] = MODINFO_NAME;
fake_preload[i++] = strlen("kernel") + 1;
strcpy((char*)&fake_preload[i], "kernel");
/* ['k' 'e' 'r' 'n'] ['e' 'l' '\0' ..] */
i += 2;
fake_preload[i++] = MODINFO_TYPE;
fake_preload[i++] = strlen("elf kernel") + 1;
strcpy((char*)&fake_preload[i], "elf kernel");
/* ['e' 'l' 'f' ' '] ['k' 'e' 'r' 'n'] ['e' 'l' '\0' ..] */
i += 3;
#ifdef __powerpc64__
/* Padding -- Fields start on u_long boundaries */
fake_preload[i++] = 0;
#endif
fake_preload[i++] = MODINFO_ADDR;
fake_preload[i++] = sizeof(vm_offset_t);
*(vm_offset_t *)&fake_preload[i] =
(vm_offset_t)(__startkernel);
i += (sizeof(vm_offset_t) / 4);
fake_preload[i++] = MODINFO_SIZE;
fake_preload[i++] = sizeof(vm_offset_t);
*(vm_offset_t *)&fake_preload[i] =
(vm_offset_t)(__endkernel) - (vm_offset_t)(__startkernel);
i += (sizeof(vm_offset_t) / 4);
/*
* MODINFOMD_SSYM and MODINFOMD_ESYM cannot be provided here,
* as the memory comes from outside the loaded ELF sections.
*
* If the symbols are being provided by other means (MFS), the
* tables will be loaded into the debugger directly.
*/
/* Null field at end to mark end of data. */
fake_preload[i++] = 0;
fake_preload[i] = 0;
preload_metadata = (void*)fake_preload;
}
/*
* Flush the D-cache for non-DMA I/O so that the I-cache can
* be made coherent later.