[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: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/i386/boot/edd.c b/arch/i386/boot/edd.c
index d65dd21..82b5c84 100644
--- a/arch/i386/boot/edd.c
+++ b/arch/i386/boot/edd.c
@@ -37,11 +37,10 @@
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 @@
/* 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 @@
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 @@
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 @@
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;
}
}