load ACPI tables from fw_cfg

1 files changed, 160 insertions, 0 deletions

diff --git a/tables.c b/tables.c
new file mode 100644
index 0000000..3f59b3e
--- /dev/null
+++ b/tables.c
@@ -0,0 +1,160 @@
+#include "bios.h"
+#include "stdio.h"
+#include "fw_cfg.h"
+#include "string.h"
+
+struct loader_cmd {
+	uint32_t cmd;
+	union {
+#define CMD_QUIT 0
+#define CMD_ALLOC 1
+		struct {
+			char file[56];
+			uint32_t align;
+			uint8_t zone;
+		} alloc;
+#define CMD_PTR 2
+		struct {
+			char dest[56];
+			char src[56];
+			uint32_t offset;
+			uint8_t size;
+		} ptr;
+#define CMD_CHECKSUM 3
+		struct {
+			char file[56];
+			uint32_t offset;
+			uint32_t start;
+			uint32_t len;
+		} checksum;
+		uint8_t pad[124];
+	};
+} __attribute__((__packed__));
+
+enum {
+	ALLOC_HIGH = 1,
+	ALLOC_FSEG = 2
+};
+
+static uint8_t *file_address[20];
+
+static inline void *id_to_addr(int fw_cfg_id)
+{
+	return file_address[fw_cfg_id];
+}
+
+static inline void set_file_addr(int fw_cfg_id, void *p)
+{
+	file_address[fw_cfg_id] = p;
+}
+
+static void do_alloc(char *file, uint32_t align, uint8_t zone)
+{
+	int id = fw_cfg_file_id(file);
+	int n = fw_cfg_file_size(id);
+	char *p;
+
+	if (id == -1)
+		panic();
+
+	if (align > 16)
+		n += align - 16;
+
+	if (zone == ALLOC_FSEG)
+		p = malloc_fseg(n);
+	else
+		p = malloc(n);
+
+	p = (char *)((uintptr_t)(p + align - 1) & -align);
+
+	set_file_addr(id, p);
+	fw_cfg_file_select(id);
+	fw_cfg_read(p, n);
+}
+
+static void do_ptr(char *dest, char *src, uint32_t offset, uint8_t size)
+{
+	char *p, *q;
+	int id;
+	union {
+		long long ll;
+		char b[8];
+	} data;
+
+	id = fw_cfg_file_id(src);
+	p = id_to_addr(id);
+	if (!p)
+		panic();
+
+	id = fw_cfg_file_id(dest);
+	q = id_to_addr(id);
+	if (!q)
+		panic();
+
+	q += offset;
+
+	/* Assumes little endian */
+	data.ll = 0;
+	memcpy(&data.b, q, size);
+	data.ll += (uintptr_t) p;
+	memcpy(q, &data.b, size);
+}
+
+static inline uint8_t csum8(uint8_t *buf, uint32_t len)
+{
+	uint32_t s = 0;
+	while (len-- > 0)
+		s += *buf++;
+	return s;
+}
+static void do_checksum(char *file, uint32_t offset, uint32_t start, uint32_t len)
+{
+	uint8_t *p;
+	int id;
+	int n;
+
+	id = fw_cfg_file_id(file);
+	p = id_to_addr(id);
+	if (!p)
+		panic();
+
+	n = fw_cfg_file_size(id);
+	if (offset >= n || n < start || len > n - start)
+		panic();
+
+	p[offset] -= csum8(&p[start], len);
+}
+
+void extract_acpi(void)
+{
+	int id = fw_cfg_file_id("etc/table-loader");
+	int n = fw_cfg_file_size(id);
+	struct loader_cmd script[n / sizeof(struct loader_cmd)];
+	int i;
+
+	if (!n)
+		return;
+
+	fw_cfg_file_select(id);
+	fw_cfg_read(script, n);
+
+	for (i = 0; i < ARRAY_SIZE(script); i++) {
+		struct loader_cmd *s = &script[i];
+		switch(script[i].cmd) {
+		case CMD_ALLOC:
+			do_alloc(s->alloc.file, s->alloc.align, s->alloc.zone);
+			break;
+		case CMD_PTR:
+			do_ptr(s->ptr.dest, s->ptr.src, s->ptr.offset, s->ptr.size);
+			break;
+		case CMD_CHECKSUM:
+			do_checksum(s->checksum.file, s->checksum.offset,
+				    s->checksum.start, s->checksum.len);
+			break;
+		case CMD_QUIT:
+			return;
+		default:
+			panic();
+		}
+	}
+}