diff options
Diffstat (limited to 'sys/dev/acpi/dsdt.c')
| -rw-r--r-- | sys/dev/acpi/dsdt.c | 45 |
1 files changed, 24 insertions, 21 deletions
diff --git a/sys/dev/acpi/dsdt.c b/sys/dev/acpi/dsdt.c index 5b3a16d4e01..021670f4d18 100644 --- a/sys/dev/acpi/dsdt.c +++ b/sys/dev/acpi/dsdt.c @@ -1,4 +1,4 @@ -/* $OpenBSD: dsdt.c,v 1.90 2007/10/08 04:15:15 krw Exp $ */ +/* $OpenBSD: dsdt.c,v 1.91 2007/11/03 17:23:25 jordan Exp $ */ /* * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org> * @@ -2203,30 +2203,33 @@ aml_parsename(struct aml_scope *scope) return name; } -/* Decode AML Length field */ +/* Decode AML Length field + * AML Length field is encoded: + * byte0 byte1 byte2 byte3 + * 00xxxxxx : if upper bits == 00, length = xxxxxx + * 01--xxxx yyyyyyyy : if upper bits == 01, length = yyyyyyyyxxxx + * 10--xxxx yyyyyyyy zzzzzzzz : if upper bits == 10, length = zzzzzzzzyyyyyyyyxxxx + * 11--xxxx yyyyyyyy zzzzzzzz wwwwwwww : if upper bits == 11, length = wwwwwwwwzzzzzzzzyyyyyyyyxxxx + */ int aml_parselength(struct aml_scope *scope) { - int len = (*scope->pos & 0xF); + int len; + uint8_t lcode; - switch (*scope->pos >> 6) { - case 0x00: - len = scope->pos[0] & 0x3F; - scope->pos += 1; - break; - case 0x01: - len += (scope->pos[1]<<4L); - scope->pos += 2; - break; - case 0x02: - len += (scope->pos[1]<<4L) + (scope->pos[2]<<12L); - scope->pos += 3; - break; - case 0x03: - len += (scope->pos[1]<<4L) + (scope->pos[2]<<12L) + - (scope->pos[3]<<20L); - scope->pos += 4; - break; + lcode = *(scope->pos++); + if (lcode <= 0x3F) { + return lcode; + } + + /* lcode >= 0x40, multibyte length, get first byte of extended length */ + len = lcode & 0xF; + len += *(scope->pos++) << 4L; + if (lcode >= 0x80) { + len += *(scope->pos++) << 12L; + } + if (lcode >= 0xC0) { + len += *(scope->pos++) << 20L; } return len; } |