提交 03967ce2 编写于 作者: S Simon Glass 提交者: Bin Meng

acpigen: Support writing a package

A package collects together several elements. Add an easy way of writing
a package header and updating its length later.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NWolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>
上级 7e148f2e
......@@ -17,6 +17,11 @@ struct acpi_ctx;
/* Top 4 bits of the value used to indicate a three-byte length value */
#define ACPI_PKG_LEN_3_BYTES 0x80
/* ACPI Op/Prefix codes */
enum {
PACKAGE_OP = 0x12,
};
/**
* acpigen_get_current() - Get the current ACPI code output pointer
*
......@@ -106,4 +111,31 @@ void acpigen_write_len_f(struct acpi_ctx *ctx);
*/
void acpigen_pop_len(struct acpi_ctx *ctx);
/**
* acpigen_write_package() - Start writing a package
*
* A package collects together a number of elements in the ACPI code. To write
* a package use:
*
* acpigen_write_package(ctx, 3);
* ...write things
* acpigen_pop_len()
*
* If you don't know the number of elements in advance, acpigen_write_package()
* returns a pointer to the value so you can update it later:
*
* char *num_elements = acpigen_write_package(ctx, 0);
* ...write things
* *num_elements += 1;
* ...write things
* *num_elements += 1;
* acpigen_pop_len()
*
* @ctx: ACPI context pointer
* @nr_el: Number of elements (0 if not known)
* @returns pointer to the number of elements, which can be updated by the
* caller if needed
*/
char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el);
#endif
......@@ -71,6 +71,18 @@ void acpigen_pop_len(struct acpi_ctx *ctx)
p[2] = len >> 12 & 0xff;
}
char *acpigen_write_package(struct acpi_ctx *ctx, int nr_el)
{
char *p;
acpigen_emit_byte(ctx, PACKAGE_OP);
acpigen_write_len_f(ctx);
p = ctx->current;
acpigen_emit_byte(ctx, nr_el);
return p;
}
void acpigen_emit_stream(struct acpi_ctx *ctx, const char *data, int size)
{
int i;
......
......@@ -404,3 +404,30 @@ static int dm_test_acpi_len(struct unit_test_state *uts)
return 0;
}
DM_TEST(dm_test_acpi_len, 0);
/* Test writing a package */
static int dm_test_acpi_package(struct unit_test_state *uts)
{
struct acpi_ctx *ctx;
char *num_elements;
u8 *ptr;
ut_assertok(alloc_context(&ctx));
ptr = acpigen_get_current(ctx);
num_elements = acpigen_write_package(ctx, 3);
ut_asserteq_ptr(num_elements, ptr + 4);
/* For ease of testing, just emit a byte, not valid package contents */
acpigen_emit_byte(ctx, 0x23);
acpigen_pop_len(ctx);
ut_asserteq(PACKAGE_OP, ptr[0]);
ut_asserteq(5, get_length(ptr + 1));
ut_asserteq(3, ptr[4]);
free_context(&ctx);
return 0;
}
DM_TEST(dm_test_acpi_package, 0);
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