It is possible to read out the framebuffer size via msr. The size information is needed for VESA later.
Signed-off-by: Christian Gmeiner christian.gmeiner@gmail.com --- vgasrc/geodevga.c | 27 +++++++++++++++++++++++++++ vgasrc/geodevga.h | 1 + 2 files changed, 28 insertions(+)
diff --git a/vgasrc/geodevga.c b/vgasrc/geodevga.c index ae606a7..636d55b 100644 --- a/vgasrc/geodevga.c +++ b/vgasrc/geodevga.c @@ -106,6 +106,30 @@ static int legacyio_check(void) return ret; }
+static u32 framebuffer_size(void) +{ + u32 val; + union u64_u32_u msr; + + /* We use the P2D_R0 msr to read out the number of pages. + * One page has a size of 4k + * + * Bit Name Description + * 39:20 PMAX Physical Memory Address Max + * 19:0 PMIX Physical Memory Address Min + * + */ + msr = geode_msrRead(GLIU0_P2D_RO); + + u32 pmax = ((msr.hi & 0xff) << 12) | ((msr.lo & 0xfff00000) >> 20); + u32 pmin = (msr.lo & 0x000fffff); + + val = pmax - pmin; + val += 1; + + /* The page size is 4k */ + return (val << 12); +}
/**************************************************************** * Init Functions @@ -140,6 +164,9 @@ static int dc_setup(void)
geode_memWrite(dc_base + DC_UNLOCK, 0x0, DC_LOCK_LOCK);
+ u32 fb_size = framebuffer_size(); // in byte + dprintf(1, "%d KB of video memory at 0x%08x\n", fb_size / 1024, fb); + return 0; }
diff --git a/vgasrc/geodevga.h b/vgasrc/geodevga.h index 7098037..14e33d6 100644 --- a/vgasrc/geodevga.h +++ b/vgasrc/geodevga.h @@ -26,6 +26,7 @@ #define MSR_GLIU0 (1 << 28) #define MSR_GLIU0_BASE4 (MSR_GLIU0 + 0x23) /* LX */ #define GLIU0_P2D_BM_4 (MSR_GLIU0 + 0x24) /* GX2 */ +#define GLIU0_P2D_RO (MSR_GLIU0 + 0x29) #define GLIU0_IOD_BM_0 (MSR_GLIU0 + 0xE0) #define GLIU0_IOD_BM_1 (MSR_GLIU0 + 0xE1) #define DC_SPARE 0x80000011