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| author | Michael Brown | 2009-02-23 09:43:27 +0100 |
|---|---|---|
| committer | Michael Brown | 2009-02-23 09:43:27 +0100 |
| commit | 784d3f336eced5db53a02b272e77927ce20c2236 (patch) | |
| tree | 08a7a00cc511367f660ebd4557f4ce9552ca57b2 | |
| parent | [pxeprefix] Search for the PXE entry points through all methods (diff) | |
| download | ipxe-784d3f336eced5db53a02b272e77927ce20c2236.tar.gz ipxe-784d3f336eced5db53a02b272e77927ce20c2236.tar.xz ipxe-784d3f336eced5db53a02b272e77927ce20c2236.zip | |
[pxe] Set %ax to zero on entry to PXE NBP
This is not strictly an entry requirement, but it does mean that a PXE
NBP returning without setting %ax will appear to have returned
success.
| -rw-r--r-- | src/arch/i386/interface/pxe/pxe_call.c | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/src/arch/i386/interface/pxe/pxe_call.c b/src/arch/i386/interface/pxe/pxe_call.c index 320ae125..06dee25c 100644 --- a/src/arch/i386/interface/pxe/pxe_call.c +++ b/src/arch/i386/interface/pxe/pxe_call.c @@ -433,23 +433,24 @@ void pxe_init_structures ( void ) { * @ret rc Return status code */ int pxe_start_nbp ( void ) { - int discard_b, discard_c, discard_d; + int discard_b, discard_c, discard_d, discard_D; uint16_t rc; /* Far call to PXE NBP */ - __asm__ __volatile__ ( REAL_CODE ( "pushw %%cx\n\t" - "pushw %%ax\n\t" - "movw %%cx, %%es\n\t" + __asm__ __volatile__ ( REAL_CODE ( "movw %%cx, %%es\n\t" + "pushw %%es\n\t" + "pushw %%di\n\t" "sti\n\t" "lcall $0, $0x7c00\n\t" "addw $4, %%sp\n\t" ) : "=a" ( rc ), "=b" ( discard_b ), - "=c" ( discard_c ), "=d" ( discard_d ) - : "a" ( __from_text16 ( &ppxe ) ), - "b" ( __from_text16 ( &pxenv ) ), + "=c" ( discard_c ), "=d" ( discard_d ), + "=D" ( discard_D ) + : "a" ( 0 ), "b" ( __from_text16 ( &pxenv ) ), "c" ( rm_cs ), - "d" ( virt_to_phys ( &pxenv ) ) - : "esi", "edi", "ebp", "memory" ); + "d" ( virt_to_phys ( &pxenv ) ), + "D" ( __from_text16 ( &ppxe ) ) + : "esi", "ebp", "memory" ); return rc; } |