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| author | Michael Brown <mcb30@ipxe.org> | 2022-09-18 13:35:58 +0100 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2022-09-18 13:35:58 +0100 |
| commit | 9448ac544574dc11e1af204de39fcfddbbccb2af (patch) | |
| tree | 89b97be0d8b8e395b0e94613fb81fa1eebfad144 | |
| parent | be667ba94822877036f6c80992554ed32314a1f2 (diff) | |
| download | ipxe-9448ac544574dc11e1af204de39fcfddbbccb2af.zip ipxe-9448ac544574dc11e1af204de39fcfddbbccb2af.tar.gz ipxe-9448ac544574dc11e1af204de39fcfddbbccb2af.tar.bz2 | |
[bios] Allow pcibios_discover() to return an empty range
Allow pcibios_discover() to return an empty range if the INT 1A,B101
PCI BIOS installation check call fails.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
| -rw-r--r-- | src/arch/x86/interface/pcbios/pcibios.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/arch/x86/interface/pcbios/pcibios.c b/src/arch/x86/interface/pcbios/pcibios.c index cf81863..6f31ce9 100644 --- a/src/arch/x86/interface/pcbios/pcibios.c +++ b/src/arch/x86/interface/pcbios/pcibios.c @@ -42,7 +42,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); static void pcibios_discover ( uint32_t busdevfn __unused, struct pci_range *range ) { int discard_a, discard_D; - uint8_t max_bus; + uint16_t num_bus; /* We issue this call using flat real mode, to work around a * bug in some HP BIOSes. @@ -50,10 +50,12 @@ static void pcibios_discover ( uint32_t busdevfn __unused, __asm__ __volatile__ ( REAL_CODE ( "call flatten_real_mode\n\t" "stc\n\t" "int $0x1a\n\t" + "movzbw %%cl, %%cx\n\t" + "incw %%cx\n\t" "jnc 1f\n\t" "xorw %%cx, %%cx\n\t" "\n1:\n\t" ) - : "=c" ( max_bus ), "=a" ( discard_a ), + : "=c" ( num_bus ), "=a" ( discard_a ), "=D" ( discard_D ) : "a" ( PCIBIOS_INSTALLATION_CHECK >> 16 ), "D" ( 0 ) @@ -61,7 +63,7 @@ static void pcibios_discover ( uint32_t busdevfn __unused, /* Populate range */ range->start = PCI_BUSDEVFN ( 0, 0, 0, 0 ); - range->count = PCI_BUSDEVFN ( 0, ( max_bus + 1 ), 0, 0 ); + range->count = PCI_BUSDEVFN ( 0, num_bus, 0, 0 ); } /** |