diff options
| -rw-r--r-- | src/arch/x86/boot/acpigen.c | 49 |
1 files changed, 30 insertions, 19 deletions
diff --git a/src/arch/x86/boot/acpigen.c b/src/arch/x86/boot/acpigen.c index 4b12a76cde..58e783ed41 100644 --- a/src/arch/x86/boot/acpigen.c +++ b/src/arch/x86/boot/acpigen.c @@ -17,11 +17,13 @@ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ -/* how many nesting we support */ +/* How much nesting do we support? */ #define ACPIGEN_LENSTACK_SIZE 10 -/* if you need to change this, change the acpigen_write_f and - acpigen_patch_len */ +/* + * If you need to change this, change acpigen_write_f and + * acpigen_patch_len + */ #define ACPIGEN_MAXLEN 0xfff @@ -38,7 +40,7 @@ int ltop = 0; int acpigen_write_len_f(void) { ASSERT(ltop < (ACPIGEN_LENSTACK_SIZE - 1)) - len_stack[ltop++] = gencurrent; + len_stack[ltop++] = gencurrent; acpigen_emit_byte(0); acpigen_emit_byte(0); return 2; @@ -47,7 +49,7 @@ int acpigen_write_len_f(void) void acpigen_patch_len(int len) { ASSERT(len <= ACPIGEN_MAXLEN) - ASSERT(ltop > 0) + ASSERT(ltop > 0) char *p = len_stack[--ltop]; /* generate store length for 0xfff max */ p[0] = (0x40 | (len & 0xf)); @@ -148,10 +150,14 @@ int acpigen_emit_stream(const char *data, int size) return size; } -/* The NameString are bit tricky, each element can be 4 chars, if - less its padded with underscore. Check 18.2.2 and 18.4 - and 5.3 of ACPI specs 3.0 for details -*/ +/* + * The naming conventions for ACPI namespace names are a bit tricky as + * each element has to be 4 chars wide (»All names are a fixed 32 bits.«) + * and »By convention, when an ASL compiler pads a name shorter than 4 + * characters, it is done so with trailing underscores (‘_’).«. + * + * Check sections 5.3, 18.2.2 and 18.4 of ACPI spec 3.0 for details. + */ static int acpigen_emit_simple_namestring(const char *name) { int i, len = 0; @@ -205,13 +211,13 @@ int acpigen_emit_namestring(const char *namepath) { int dotpos = 0; int len = 0; - /* we can start with a \ */ + /* We can start with a »\«. */ if (namepath[0] == '\\') { len += acpigen_emit_byte('\\'); namepath++; } - /* and there can be any number of ^ */ + /* And there can be any number of »^«. */ while (namepath[0] == '^') { len += acpigen_emit_byte('^'); namepath++; @@ -370,7 +376,9 @@ int acpigen_write_empty_PTC(void) return len + nlen; } -/* generates a func with max supported P states */ +/* + * Generates a func with max supported P-states. + */ int acpigen_write_PPC(u8 nr) { /* @@ -396,7 +404,10 @@ int acpigen_write_PPC(u8 nr) return len; } -/* generates a func with max supported P states */ +/* + * Generates a func with max supported P-states saved + * in the variable PPCM. + */ int acpigen_write_PPC_NVS(void) { /* @@ -621,7 +632,7 @@ int acpigen_write_io16(u16 min, u16 max, u8 align, u8 len, u8 decode16) * Bit2-0: 111 (0x7) => 7 Bytes long */ acpigen_emit_byte(0x47); - /* does the device decode all 16 or just 10 bits? */ + /* Does the device decode all 16 or just 10 bits? */ /* bit1-7 are ignored */ acpigen_emit_byte(decode16 ? 0x01 : 0x00); /* minimum base address the device may be configured for */ @@ -642,12 +653,12 @@ int acpigen_write_resourcetemplate_header(void) /* * A ResourceTemplate() is a Buffer() with a * (Byte|Word|DWord) containing the length, followed by one or more - * resource items, terminated by the end tag + * resource items, terminated by the end tag. * (small item 0xf, len 1) */ - len = acpigen_emit_byte(0x11); /* Buffer opcode */ + len = acpigen_emit_byte(0x11); /* Buffer opcode */ len += acpigen_write_len_f(); - len += acpigen_emit_byte(0x0b); /* Word opcode */ + len += acpigen_emit_byte(0x0b); /* Word opcode */ len_stack[ltop++] = acpigen_get_current(); len += acpigen_emit_byte(0x00); len += acpigen_emit_byte(0x00); @@ -700,13 +711,13 @@ int acpigen_write_mainboard_resource_template(void) len = acpigen_write_resourcetemplate_header(); start = acpigen_get_current(); - /* Add reserved memory ranges */ + /* Add reserved memory ranges. */ search_global_resources( IORESOURCE_MEM | IORESOURCE_RESERVE, IORESOURCE_MEM | IORESOURCE_RESERVE, acpigen_add_mainboard_rsvd_mem32, 0); - /* Add reserved io ranges */ + /* Add reserved io ranges. */ search_global_resources( IORESOURCE_IO | IORESOURCE_RESERVE, IORESOURCE_IO | IORESOURCE_RESERVE, |