narenas
/
opengnsys_ipxe
mirror of https://github.com/ipxe/ipxe.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

[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>
pull/583/merge
Michael Brown 2022-09-18 13:35:58 +01:00
parent be667ba948
commit 9448ac5445
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/arch/x86/interface/pcbios/pcibios.c
View File

@ -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 );
}
/**