Aaron Durbin (adurbin@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2920
-gerrit
commit e7819449d30b4bd790a80c4963f26f2ece8daf81 Author: Aaron Durbin adurbin@chromium.org Date: Tue Mar 26 13:34:37 2013 -0500
libpayload: add x86 ROM variable MTRR support
On x86, coreboot may allocate a variable range MTRR for enabling caching of the system ROM. Add the ability to parse this structure and add the result to the sysinfo structure.
An example usage implementation would be to obtain the variable MTRR index that covers the ROM from the sysinfo structure. Then one would disable caching and change the MTRR type from uncacheable to write-protect and enable caching. The opposite sequence is required to tearn down the caching.
Change-Id: I3bfe2028d8574d3adb1d85292abf8f1372cf97fa Signed-off-by: Aaron Durbin adurbin@chromium.org --- payloads/libpayload/arch/x86/coreboot.c | 17 ++++++++++++++++- payloads/libpayload/include/coreboot_tables.h | 12 ++++++++++++ payloads/libpayload/include/sysinfo.h | 5 +++++ 3 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/payloads/libpayload/arch/x86/coreboot.c b/payloads/libpayload/arch/x86/coreboot.c index f4f9b86..6c6122d 100644 --- a/payloads/libpayload/arch/x86/coreboot.c +++ b/payloads/libpayload/arch/x86/coreboot.c @@ -158,6 +158,12 @@ static void cb_parse_framebuffer(void *ptr, struct sysinfo_t *info) } #endif
+static void cb_parse_x86_rom_var_mtrr(void *ptr, struct sysinfo_t *info) +{ + struct cb_x86_rom_mtrr *rom_mtrr = ptr; + info->x86_rom_var_mtrr_index = rom_mtrr->index; +} + static void cb_parse_string(unsigned char *ptr, char **info) { *info = (char *)((struct cb_string *)ptr)->string; @@ -281,6 +287,9 @@ static int cb_parse_header(void *addr, int len, struct sysinfo_t *info) case CB_TAG_MRC_CACHE: cb_parse_mrc_cache(ptr, info); break; + case CB_TAG_X86_ROM_MTRR: + cb_parse_x86_rom_var_mtrr(ptr, info); + break; }
ptr += rec->size; @@ -294,7 +303,13 @@ static int cb_parse_header(void *addr, int len, struct sysinfo_t *info)
int get_coreboot_info(struct sysinfo_t *info) { - int ret = cb_parse_header(phys_to_virt(0x00000000), 0x1000, info); + int ret; + + /* Ensure the variable range MTRR index covering the ROM is set to + * an invalid value. */ + info->x86_rom_var_mtrr_index = -1; + + ret = cb_parse_header(phys_to_virt(0x00000000), 0x1000, info);
if (ret != 1) ret = cb_parse_header(phys_to_virt(0x000f0000), 0x1000, info); diff --git a/payloads/libpayload/include/coreboot_tables.h b/payloads/libpayload/include/coreboot_tables.h index 38bda55..02c9449 100644 --- a/payloads/libpayload/include/coreboot_tables.h +++ b/payloads/libpayload/include/coreboot_tables.h @@ -217,6 +217,18 @@ struct cb_vboot_handoff { uint32_t vboot_handoff_size; };
+#define CB_TAG_X86_ROM_MTRR 0x0021 +struct cb_x86_rom_mtrr { + uint32_t tag; + uint32_t size; + /* The variable range MTRR index covering the ROM. If one wants to + * enable caching the ROM, the variable MTRR needs to be set to + * write-protect. To disable the caching after enabling set the + * type to uncacheable. */ + uint32_t index; +}; + + #define CB_TAG_CMOS_OPTION_TABLE 0x00c8 struct cb_cmos_option_table { u32 tag; diff --git a/payloads/libpayload/include/sysinfo.h b/payloads/libpayload/include/sysinfo.h index e05ef9f..fd60dc3 100644 --- a/payloads/libpayload/include/sysinfo.h +++ b/payloads/libpayload/include/sysinfo.h @@ -99,6 +99,11 @@ struct sysinfo_t { void *vdat_addr; u32 vdat_size; #endif + +#ifdef CONFIG_ARCH_X86 + int x86_rom_var_mtrr_index; +#endif + void *tstamp_table; void *cbmem_cons; void *mrc_cache;
-
Aaron Durbin