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Commit 9a5f35d4 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

[x86 setup] edd.c: make sure MBR signatures actually get reported 



When filling in the MBR signature array, the setup code failed to advance
boot_params.edd_mbr_sig_buf_entries, which resulted in the valid data
being ignored.

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent c1a6e2b0

arch/i386/boot/edd.c

+11 −13
Original line number Diff line number Diff line
@@ -37,11 +37,10 @@ static int read_mbr(u8 devno, void *buf) 
	return -(u8)ax;		/* 0 or -1 */

}



static u32 read_mbr_sig(u8 devno, struct edd_info *ei)

static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)

{

	int sector_size;

	char *mbrbuf_ptr, *mbrbuf_end;

	u32 mbrsig;

	u32 buf_base, mbr_base;

	extern char _end[];
@@ -57,15 +56,15 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei) 


	/* Make sure we actually have space on the heap... */

	if (!(boot_params.hdr.loadflags & CAN_USE_HEAP))

		return 0;

		return -1;

	if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr)

		return 0;

		return -1;



	if (read_mbr(devno, mbrbuf_ptr))

		return 0;

		return -1;



	mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET];

	return mbrsig;

	*mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET];

	return 0;

}



static int get_edd_info(u8 devno, struct edd_info *ei)
@@ -132,6 +131,7 @@ void query_edd(void) 
	int do_edd = 1;

	int devno;

	struct edd_info ei, *edp;

	u32 *mbrptr;



	if (cmdline_find_option("edd", eddarg, sizeof eddarg) > 0) {

		if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip"))
@@ -140,7 +140,8 @@ void query_edd(void) 
			do_edd = 0;

	}



	edp = (struct edd_info *)boot_params.eddbuf;

	edp    = boot_params.eddbuf;

	mbrptr = boot_params.edd_mbr_sig_buffer;



	if (!do_edd)

		return;
@@ -158,11 +159,8 @@ void query_edd(void) 
			boot_params.eddbuf_entries++;

		}



		if (do_mbr) {

			u32 mbr_sig;

			mbr_sig = read_mbr_sig(devno, &ei);

			boot_params.edd_mbr_sig_buffer[devno-0x80] = mbr_sig;

		}

		if (do_mbr && !read_mbr_sig(devno, &ei, mbrptr++))

			boot_params.edd_mbr_sig_buf_entries = devno-0x80+1;

	}

}