diff options
author | Jacob Garber <jgarber1@ualberta.ca> | 2019-07-15 13:48:41 -0600 |
---|---|---|
committer | Patrick Georgi <pgeorgi@google.com> | 2019-07-19 10:01:35 +0000 |
commit | d92137adaba2898c86d696859c7c33f0a3bd7cbb (patch) | |
tree | 1269a27dad538b9d38a685ba80d1f1c93f59d13c /src/northbridge/via/vx900 | |
parent | 6e66b4e820ca90ceb1f5dc3b2cc8fa18f9293aac (diff) |
nb/via/vx900: Ensure framebuffer size is within limits
- Use log2() when rounding down size_mb to the closest power of 2.
Do a sanity check beforehand that size_mb is nonzero, else log2()
will return -1 and there will be an undefined integer shift.
- The framebuffer size needs to be between 8 and 512 MiB, so check
after all the calculations are done to make sure this is the case.
Change-Id: I3962e5cdc094c8da22d8dbadf16637e02fa98689
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Found-by: Coverity CID 1391086
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34355
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Diffstat (limited to 'src/northbridge/via/vx900')
-rw-r--r-- | src/northbridge/via/vx900/memmap.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/src/northbridge/via/vx900/memmap.c b/src/northbridge/via/vx900/memmap.c index 0c3b7bfc76..d11dc65fd6 100644 --- a/src/northbridge/via/vx900/memmap.c +++ b/src/northbridge/via/vx900/memmap.c @@ -21,6 +21,7 @@ #include <device/pci_ops.h> #include <cbmem.h> #include <console/console.h> +#include <lib.h> #include "vx900.h" @@ -78,12 +79,16 @@ void vx900_set_chrome9hd_fb_size(u32 size_mb) size_mb = max_size_mb; } - /* Now round the framebuffer size to the closest power of 2 */ - u8 fb_pow = 0; - while (size_mb >> fb_pow) - fb_pow++; - fb_pow--; - size_mb = (1 << fb_pow); + /* Now round down the framebuffer size to the closest power of 2 */ + if (size_mb == 0) + die("Framebuffer size is 0\n"); + + int fb_pow = log2(size_mb); + + size_mb = 1U << fb_pow; + + if (size_mb < CHROME_9_HD_MIN_FB_SIZE || size_mb > CHROME_9_HD_MAX_FB_SIZE) + die("Framebuffer size %u is out of range\n", size_mb); pci_update_config8(MCU, 0xa1, ~(7 << 4), (fb_pow - 2) << 4); } |