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Diffstat (limited to 'arch/i386/boot/edd.c')
-rw-r--r--arch/i386/boot/edd.c60
1 files changed, 15 insertions, 45 deletions
diff --git a/arch/i386/boot/edd.c b/arch/i386/boot/edd.c
index 658834d..bd138e4 100644
--- a/arch/i386/boot/edd.c
+++ b/arch/i386/boot/edd.c
@@ -19,57 +19,28 @@
#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
-struct edd_dapa {
- u8 pkt_size;
- u8 rsvd;
- u16 sector_cnt;
- u16 buf_off, buf_seg;
- u64 lba;
- u64 buf_lin_addr;
-};
-
/*
* Read the MBR (first sector) from a specific device.
*/
static int read_mbr(u8 devno, void *buf)
{
- struct edd_dapa dapa;
- u16 ax, bx, cx, dx, si;
-
- memset(&dapa, 0, sizeof dapa);
- dapa.pkt_size = sizeof(dapa);
- dapa.sector_cnt = 1;
- dapa.buf_off = (size_t)buf;
- dapa.buf_seg = ds();
- /* dapa.lba = 0; */
-
- ax = 0x4200; /* Extended Read */
- si = (size_t)&dapa;
- dx = devno;
- asm("pushfl; stc; int $0x13; setc %%al; popfl"
- : "+a" (ax), "+S" (si), "+d" (dx)
- : "m" (dapa)
- : "ebx", "ecx", "edi", "memory");
-
- if (!(u8)ax)
- return 0; /* OK */
+ u16 ax, bx, cx, dx;
ax = 0x0201; /* Legacy Read, one sector */
cx = 0x0001; /* Sector 0-0-1 */
dx = devno;
bx = (size_t)buf;
- asm("pushfl; stc; int $0x13; setc %%al; popfl"
- : "+a" (ax), "+c" (cx), "+d" (dx), "+b" (bx)
- : : "esi", "edi", "memory");
+ asm volatile("pushfl; stc; int $0x13; setc %%al; popfl"
+ : "+a" (ax), "+c" (cx), "+d" (dx), "+b" (bx)
+ : : "esi", "edi", "memory");
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[];
@@ -85,15 +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)
@@ -160,6 +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"))
@@ -168,7 +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;
@@ -186,11 +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;
}
}
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