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[POWERPC] zImage: Cleanup and improve prep_kernel()

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This patch rewrites prep_kernel() in the zImage wrapper code to be
clearer and more flexible.  Notable changes:

	- Handling of the initrd image from prep_kernel() has moved
into a new prep_initrd() function.
	- The address of the initrd image is now added as device tree
properties, as the kernel expects.
	- We only copy a packaged initrd image to a new location if it
is in danger of being clobbered when the kernel moves to its final
location, instead of always.
	- By default we decompress the kernel directly to address 0,
instead of requiring it to relocate itself.  Platforms (such as OF)
where doing this could clobber still-live firmware data structures can
override the vmlinux_alloc hook to provide an alternate place to
decompress the kernel.
	- We no longer pass lots of information between functions in
global variables.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
David Gibson 2007-03-05 14:24:52 +11:00 committed by Paul Mackerras
parent ad9d2716cf
commit 79c8541924
3 changed files with 120 additions and 72 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

179
arch/powerpc/boot/main.c
View File

@ -33,24 +33,21 @@ extern char _dtb_end[];
static struct gunzip_state gzstate;
struct addr_range {
unsigned long addr;
void *addr;
unsigned long size;
unsigned long memsize;
};
static struct addr_range vmlinux;
static struct addr_range vmlinuz;
static struct addr_range initrd;
static unsigned long elfoffset;
static int is_64bit;
static char elfheader[256];
struct elf_info {
unsigned long loadsize;
unsigned long memsize;
unsigned long elfoffset;
};
typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
#undef DEBUG
static int is_elf64(void *hdr)
static int parse_elf64(void *hdr, struct elf_info *info)
{
Elf64_Ehdr *elf64 = hdr;
Elf64_Phdr *elf64ph;
@ -74,15 +71,14 @@ static int is_elf64(void *hdr)
if (i >= (unsigned int)elf64->e_phnum)
return 0;
elfoffset = (unsigned long)elf64ph->p_offset;
vmlinux.size = (unsigned long)elf64ph->p_filesz;
vmlinux.memsize = (unsigned long)elf64ph->p_memsz;
info->loadsize = (unsigned long)elf64ph->p_filesz;
info->memsize = (unsigned long)elf64ph->p_memsz;
info->elfoffset = (unsigned long)elf64ph->p_offset;
is_64bit = 1;
return 1;
}
static int is_elf32(void *hdr)
static int parse_elf32(void *hdr, struct elf_info *info)
{
Elf32_Ehdr *elf32 = hdr;
Elf32_Phdr *elf32ph;
@ -98,7 +94,6 @@ static int is_elf32(void *hdr)
elf32->e_machine == EM_PPC))
return 0;
elf32 = (Elf32_Ehdr *)elfheader;
elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
if (elf32ph->p_type == PT_LOAD)
@ -106,24 +101,26 @@ static int is_elf32(void *hdr)
if (i >= elf32->e_phnum)
return 0;
elfoffset = elf32ph->p_offset;
vmlinux.size = elf32ph->p_filesz;
vmlinux.memsize = elf32ph->p_memsz;
info->loadsize = elf32ph->p_filesz;
info->memsize = elf32ph->p_memsz;
info->elfoffset = elf32ph->p_offset;
return 1;
}
static void prep_kernel(unsigned long a1, unsigned long a2)
static struct addr_range prep_kernel(void)
{
char elfheader[256];
void *vmlinuz_addr = _vmlinux_start;
unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
void *addr = 0;
struct elf_info ei;
int len;
vmlinuz.addr = (unsigned long)_vmlinux_start;
vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
/* gunzip the ELF header of the kernel */
gunzip_start(&gzstate, (void *)vmlinuz.addr, vmlinuz.size);
gunzip_start(&gzstate, vmlinuz_addr, vmlinuz_size);
gunzip_exactly(&gzstate, elfheader, sizeof(elfheader));
if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei)) {
printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
exit();
}
@ -135,55 +132,92 @@ static void prep_kernel(unsigned long a1, unsigned long a2)
* the kernel bss must be claimed (it will be zero'd by the
* kernel itself)
*/
printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
vmlinux.addr = (unsigned long)malloc(vmlinux.memsize);
if (vmlinux.addr == 0) {
printf("Can't allocate memory for kernel image !\n\r");
printf("Allocating 0x%lx bytes for kernel ...\n\r", ei.memsize);
if (platform_ops.vmlinux_alloc) {
addr = platform_ops.vmlinux_alloc(ei.memsize);
} else {
if ((unsigned long)_start < ei.memsize) {
printf("Insufficient memory for kernel at address 0!"
" (_start=%lx)\n\r", _start);
exit();
}
}
/* Finally, gunzip the kernel */
printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
/* discard up to the actual load data */
gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
len = gunzip_finish(&gzstate, addr, ei.memsize);
printf("done 0x%lx bytes\n\r", len);
flush_cache(addr, ei.loadsize);
return (struct addr_range){addr, ei.memsize};
}
static struct addr_range prep_initrd(struct addr_range vmlinux,
unsigned long initrd_addr,
unsigned long initrd_size)
{
void *devp;
u32 initrd_start, initrd_end;
/* If we have an image attached to us, it overrides anything
* supplied by the loader. */
if (_initrd_end > _initrd_start) {
printf("Attached initrd image at 0x%p-0x%p\n\r",
_initrd_start, _initrd_end);
initrd_addr = (unsigned long)_initrd_start;
initrd_size = _initrd_end - _initrd_start;
} else if (initrd_size > 0) {
printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
initrd_addr, initrd_addr + initrd_size);
}
/* If there's no initrd at all, we're done */
if (! initrd_size)
return (struct addr_range){0, 0};
/*
* If the initrd is too low it will be clobbered when the
* kernel relocates to its final location. In this case,
* allocate a safer place and move it.
*/
if (initrd_addr < vmlinux.size) {
void *old_addr = (void *)initrd_addr;
printf("Allocating 0x%lx bytes for initrd ...\n\r",
initrd_size);
initrd_addr = (unsigned long)malloc(initrd_size);
if (! initrd_addr) {
printf("Can't allocate memory for initial "
"ramdisk !\n\r");
exit();
}
printf("Relocating initrd 0x%p <- 0x%p (0x%lx bytes)\n\r",
initrd_addr, old_addr, initrd_size);
memmove((void *)initrd_addr, old_addr, initrd_size);
}
printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
/* Tell the kernel initrd address via device tree */
devp = finddevice("/chosen");
if (! devp) {
printf("Device tree has no chosen node!\n\r");
exit();
}
/*
* Now find the initrd
*
* First see if we have an image attached to us. If so
* allocate memory for it and copy it there.
*/
initrd.size = (unsigned long)(_initrd_end - _initrd_start);
initrd.memsize = initrd.size;
if (initrd.size > 0) {
printf("Allocating 0x%lx bytes for initrd ...\n\r",
initrd.size);
initrd.addr = (unsigned long)malloc((u32)initrd.size);
if (initrd.addr == 0) {
printf("Can't allocate memory for initial "
"ramdisk !\n\r");
exit();
}
printf("initial ramdisk moving 0x%lx <- 0x%lx "
"(0x%lx bytes)\n\r", initrd.addr,
(unsigned long)_initrd_start, initrd.size);
memmove((void *)initrd.addr, (void *)_initrd_start,
initrd.size);
printf("initrd head: 0x%lx\n\r",
*((unsigned long *)initrd.addr));
} else if (a2 != 0) {
/* Otherwise, see if yaboot or another loader gave us an initrd */
initrd.addr = a1;
initrd.memsize = initrd.size = a2;
printf("Using loader supplied initrd at 0x%lx (0x%lx bytes)\n\r",
initrd.addr, initrd.size);
}
initrd_start = (u32)initrd_addr;
initrd_end = (u32)initrd_addr + initrd_size;
/* Eventually gunzip the kernel */
printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
/* discard up to the actual load data */
gunzip_discard(&gzstate, elfoffset - sizeof(elfheader));
len = gunzip_finish(&gzstate, (void *)vmlinux.addr,
vmlinux.memsize);
printf("done 0x%lx bytes\n\r", len);
setprop(devp, "linux,initrd-start", &initrd_start,
sizeof(initrd_start));
setprop(devp, "linux,initrd-end", &initrd_end, sizeof(initrd_end));
flush_cache((void *)vmlinux.addr, vmlinux.size);
return (struct addr_range){(void *)initrd_addr, initrd_size};
}
/* A buffer that may be edited by tools operating on a zImage binary so as to
@ -223,6 +257,7 @@ struct console_ops console_ops;
void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
{
struct addr_range vmlinux, initrd;
kernel_entry_t kentry;
char cmdline[COMMAND_LINE_SIZE];
unsigned long ft_addr = 0;
@ -242,7 +277,8 @@ void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
_start, sp);
prep_kernel(a1, a2);
vmlinux = prep_kernel();
initrd = prep_initrd(vmlinux, a1, a2);
/* If cmdline came from zimage wrapper or if we can edit the one
* in the dt, print it out and edit it, if possible.
@ -271,8 +307,7 @@ void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
if (ft_addr)
kentry(ft_addr, 0, NULL);
else
/* XXX initrd addr/size should be passed in properties */
kentry(initrd.addr, initrd.size, promptr);
kentry((unsigned long)initrd.addr, initrd.size, promptr);
/* console closed so printf below may not work */
printf("Error: Linux kernel returned to zImage boot wrapper!\n\r");

12
arch/powerpc/boot/of.c
View File

@ -208,6 +208,17 @@ static void of_image_hdr(const void *hdr)
}
}
static void *of_vmlinux_alloc(unsigned long size)
{
void *p = malloc(size);
if (!p) {
printf("Can't allocate memory for kernel image!\n\r");
exit();
}
return p;
}
static void of_exit(void)
{
call_prom("exit", 0, 0);
@ -261,6 +272,7 @@ int platform_init(void *promptr, char *dt_blob_start, char *dt_blob_end)
platform_ops.image_hdr = of_image_hdr;
platform_ops.malloc = of_try_claim;
platform_ops.exit = of_exit;
platform_ops.vmlinux_alloc = of_vmlinux_alloc;
dt_ops.finddevice = of_finddevice;
dt_ops.getprop = of_getprop;

1
arch/powerpc/boot/ops.h
View File

@ -25,6 +25,7 @@ struct platform_ops {
void (*free)(void *ptr);
void * (*realloc)(void *ptr, unsigned long size);
void (*exit)(void);
void * (*vmlinux_alloc)(unsigned long size);
};
extern struct platform_ops platform_ops;