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| author | Shao Miller | 2010-01-24 04:12:27 +0100 |
|---|---|---|
| committer | Marty Connor | 2010-01-24 13:54:42 +0100 |
| commit | 112a3f2de281a2afb23ced2082d555720de7c9b0 (patch) | |
| tree | 50f91813ae58ed102fa4b7a47bd9f90f9d99732c /src/arch/i386/include | |
| parent | [dhcp] Keep multiple DHCP offers received, and use them intelligently (diff) | |
| download | ipxe-112a3f2de281a2afb23ced2082d555720de7c9b0.tar.gz ipxe-112a3f2de281a2afb23ced2082d555720de7c9b0.tar.xz ipxe-112a3f2de281a2afb23ced2082d555720de7c9b0.zip | |
[pxe] Introduce PXE exit hook for NBP chaining
It might be the case that we wish to chain to an NBP without
being "in the way". We now implement a hook in our exit path
for gPXE *.*pxe build targets. The hook is a pointer to a
SEG16:OFF16 which we try to jump to during exit. By default,
this pointer results in the usual exit path.
We also implement the "pxenv_file_exit_hook" PXE API routine
to allow the user to specify an alternate SEG16:OFF16 to jump
to during exit.
Unfortunately, this additional PXE extension has a cost
in code size. Fortunately, a look at the size difference
for a gPXE .rom build target shows zero size difference
after compression.
The routine is documented in doc/pxe_extensions as follows:
FILE EXIT HOOK
Op-Code: PXENV_FILE_EXIT_HOOK (00e7h)
Input: Far pointer to a t_PXENV_FILE_EXIT_HOOK parameter
structure that has been initialized by the caller.
Output: PXENV_EXIT_SUCCESS or PXENV_EXIT_FAILURE must be
returned in AX. The Status field in the parameter
structure must be set to one of the values represented
by the PXENV_STATUS_xxx constants.
Description:Modify the exit path to jump to the specified code.
Only valid for pxeprefix-based builds.
typedef struct s_PXENV_FILE_EXIT_HOOK {
PXENV_STATUS_t Status;
SEGOFF16_t Hook;
} t_PXENV_FILE_EXIT_HOOK;
Set before calling API service:
Hook: The SEG16:OFF16 of the code to jump to.
Returned from API service:
Status: See PXENV_STATUS_xxx constants.
Requested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Shao Miller <shao.miller@yrdsb.edu.on.ca>
Signed-off-by: Marty Connor <mdc@etherboot.org>
Diffstat (limited to 'src/arch/i386/include')
| -rw-r--r-- | src/arch/i386/include/pxe.h | 1 | ||||
| -rw-r--r-- | src/arch/i386/include/pxe_api.h | 22 |
2 files changed, 23 insertions, 0 deletions
diff --git a/src/arch/i386/include/pxe.h b/src/arch/i386/include/pxe.h index b0cabef0d..041ee7bab 100644 --- a/src/arch/i386/include/pxe.h +++ b/src/arch/i386/include/pxe.h @@ -67,6 +67,7 @@ union u_PXENV_ANY { struct s_PXENV_GET_FILE_SIZE get_file_size; struct s_PXENV_FILE_EXEC file_exec; struct s_PXENV_FILE_API_CHECK file_api_check; + struct s_PXENV_FILE_EXIT_HOOK file_exit_hook; }; typedef union u_PXENV_ANY PXENV_ANY_t; diff --git a/src/arch/i386/include/pxe_api.h b/src/arch/i386/include/pxe_api.h index ba0dbdc0a..92f046f79 100644 --- a/src/arch/i386/include/pxe_api.h +++ b/src/arch/i386/include/pxe_api.h @@ -1778,6 +1778,28 @@ extern PXENV_EXIT_t pxenv_file_api_check ( struct s_PXENV_FILE_API_CHECK *file_a /** @} */ /* pxenv_file_api_check */ +/** @defgroup pxenv_file_exit_hook PXENV_FILE_EXIT_HOOK + * + * FILE EXIT HOOK + * + * @{ + */ + +/** PXE API function code for pxenv_file_exit_hook() */ +#define PXENV_FILE_EXIT_HOOK 0x00e7 + +/** Parameter block for pxenv_file_exit_hook() */ +struct s_PXENV_FILE_EXIT_HOOK { + PXENV_STATUS_t Status; /**< PXE status code */ + SEGOFF16_t Hook; /**< SEG16:OFF16 to jump to */ +} PACKED; + +typedef struct s_PXENV_FILE_EXIT_HOOK PXENV_FILE_EXIT_HOOK_t; + +extern PXENV_EXIT_t pxenv_file_exit_hook ( struct s_PXENV_FILE_EXIT_HOOK *file_exit_hook ); + +/** @} */ /* pxenv_file_exit_hook */ + /** @} */ /* pxe_file_api */ /** @defgroup pxe_loader_api PXE Loader API |