android_kernel_xiaomi_sm8350/arch/powerpc/boot/ops.h
David Gibson cd197ffcf1 [POWERPC] zImage: Cleanup and improve zImage entry point
This patch re-organises the way the zImage wrapper code is entered, to
allow more flexibility on platforms with unusual entry conditions.
After this patch, a platform .o file has two options:

1) It can define a _zimage_start, in which case the platform code gets
   control from the very beginning of execution.  In this case the
   platform code is responsible for relocating the zImage if necessary,
   clearing the BSS, performing any platform specific initialization, and
   finally calling start() to load and enter the kernel.

2) It can define platform_init().  In this case the generic crt0.S
   handles initial entry, and calls platform_init() before calling
   start().  The signature of platform_init() is changed, however, to
   take up to 5 parameters (in r3..r7) as they come from the platform's
   initial loader, instead of a fixed set of parameters based on OF's
   usage.

   When using the generic crt0.S, the platform .o can optionally
   supply a custom stack to use, using the BSS_STACK() macro.  If this
   is not supplied, the crt0.S will assume that the loader has
   supplied a usable stack.

In either case, the platform code communicates information to the
generic code (specifically, a PROM pointer for OF systems, and/or an
initrd image address supplied by the bootloader) via a global
structure "loader_info".

In addition the wrapper script is rearranged to ensure that the
platform .o is always linked first.  This means that platforms where
the zImage entry point is at a fixed address or offset, rather than
being encoded in the binary header can be supported using option (1).

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-13 13:35:03 +11:00

114 lines
2.8 KiB
C

/*
* Global definition of all the bootwrapper operations.
*
* Author: Mark A. Greer <mgreer@mvista.com>
*
* 2006 (c) MontaVista Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#ifndef _PPC_BOOT_OPS_H_
#define _PPC_BOOT_OPS_H_
#include "types.h"
#define COMMAND_LINE_SIZE 512
#define MAX_PATH_LEN 256
#define MAX_PROP_LEN 256 /* What should this be? */
/* Platform specific operations */
struct platform_ops {
void (*fixups)(void);
void (*image_hdr)(const void *);
void * (*malloc)(u32 size);
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;
/* Device Tree operations */
struct dt_ops {
void * (*finddevice)(const char *name);
int (*getprop)(const void *phandle, const char *name, void *buf,
const int buflen);
int (*setprop)(const void *phandle, const char *name,
const void *buf, const int buflen);
unsigned long (*finalize)(void);
};
extern struct dt_ops dt_ops;
/* Console operations */
struct console_ops {
int (*open)(void);
void (*write)(char *buf, int len);
void (*edit_cmdline)(char *buf, int len);
void (*close)(void);
void *data;
};
extern struct console_ops console_ops;
/* Serial console operations */
struct serial_console_data {
int (*open)(void);
void (*putc)(unsigned char c);
unsigned char (*getc)(void);
u8 (*tstc)(void);
void (*close)(void);
};
struct loader_info {
void *promptr;
unsigned long initrd_addr, initrd_size;
};
extern struct loader_info loader_info;
void start(void *sp);
int ft_init(void *dt_blob, unsigned int max_size, unsigned int max_find_device);
int serial_console_init(void);
int ns16550_console_init(void *devp, struct serial_console_data *scdp);
void *simple_alloc_init(char *base, u32 heap_size, u32 granularity,
u32 max_allocs);
static inline void *finddevice(const char *name)
{
return (dt_ops.finddevice) ? dt_ops.finddevice(name) : NULL;
}
static inline int getprop(void *devp, const char *name, void *buf, int buflen)
{
return (dt_ops.getprop) ? dt_ops.getprop(devp, name, buf, buflen) : -1;
}
static inline int setprop(void *devp, const char *name, void *buf, int buflen)
{
return (dt_ops.setprop) ? dt_ops.setprop(devp, name, buf, buflen) : -1;
}
static inline void *malloc(u32 size)
{
return (platform_ops.malloc) ? platform_ops.malloc(size) : NULL;
}
static inline void free(void *ptr)
{
if (platform_ops.free)
platform_ops.free(ptr);
}
static inline void exit(void)
{
if (platform_ops.exit)
platform_ops.exit();
for(;;);
}
#define BSS_STACK(size) \
static char _bss_stack[size]; \
void *_platform_stack_top = _bss_stack + sizeof(_bss_stack);
#endif /* _PPC_BOOT_OPS_H_ */