GitHub-Mirror/opensbi
2
0
Fork 0
mirror of https://github.com/Fishwaldo/opensbi.git synced 2025-06-28 17:18:37 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

lib: Fix CPU capabilities detection function

Browse source 
On some platforms, misa may not be implemented. On such a platform,
reading misa will get 0. At this time, platform is required to
implement a non-standard function to detect the CPU's capabilities.
Therefore, this modification add interfaces for non-standard function.

The MXL field of misa is always at the highest two bits, whether it
is a 32-bit 64-bit or a 128-bit machine. Therefore, this modification
fixes the use of a fixed offset to detect the machine length.

Signed-off-by: Xiang Wang <merle@hardenedlinux.org>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Xiang Wang 2019-11-26 16:06:29 +05:30 • committed by Anup Patel
parent 75f903dd78
commit c96cc03fcc
4 changed files with 89 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

16
include/sbi/riscv_asm.h
View file

@ -159,22 +159,18 @@ void csr_write_num(int csr_num, unsigned long val);
__asm__ __volatile__("wfi" ::: "memory"); \
} while (0)
static inline int misa_extension(char ext)
{
return csr_read(CSR_MISA) & (1 << (ext - 'A'));
}
/* Determine CPU extension, return non-zero support */
int misa_extension(char ext);
static inline int misa_xlen(void)
{
return ((long)csr_read(CSR_MISA) < 0) ? 64 : 32;
}
/* Get MXL field of misa, return -1 on error */
int misa_xlen(void);
static inline void misa_string(char *out, unsigned int out_sz)
{
unsigned long i, val = csr_read(CSR_MISA);
unsigned long i;
for (i = 0; i < 26; i++) {
if (val & (1 << i)) {
if (misa_extension('A' + i)) {
*out = 'A' + i;
out++;
}