lib: sbi: Improve misa_string() implementation

The RISC-V ISA string does not follow alphabetical order. Instead,
we have a RISC-V specific ordering of extensions in the RISC-V ISA
string. This patch improves misa_string() implementation to return
a valid RISC-V ISA string.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This commit is contained in:
Anup Patel
2020-05-05 11:46:25 +05:30
committed by Anup Patel
parent 5338679ff0
commit dc38929dfb
3 changed files with 52 additions and 19 deletions

View File

@@ -17,8 +17,13 @@ int misa_extension_imp(char ext)
{
unsigned long misa = csr_read(CSR_MISA);
if (misa)
return misa & (1 << (ext - 'A'));
if (misa) {
if ('A' <= ext && ext <= 'Z')
return misa & (1 << (ext - 'A'));
if ('a' <= ext && ext <= 'z')
return misa & (1 << (ext - 'a'));
return 0;
}
return sbi_platform_misa_extension(sbi_platform_thishart_ptr(), ext);
}
@@ -44,6 +49,45 @@ int misa_xlen(void)
return r ? r : -1;
}
void misa_string(int xlen, char *out, unsigned int out_sz)
{
unsigned int i, pos = 0;
const char valid_isa_order[] = "iemafdqclbjtpvnsuhkorwxyzg";
if (!out)
return;
if (5 <= (out_sz - pos)) {
out[pos++] = 'r';
out[pos++] = 'v';
switch (xlen) {
case 1:
out[pos++] = '3';
out[pos++] = '2';
break;
case 2:
out[pos++] = '6';
out[pos++] = '4';
break;
case 3:
out[pos++] = '1';
out[pos++] = '2';
out[pos++] = '8';
break;
default:
return;
}
}
for (i = 0; i < array_size(valid_isa_order) && (pos < out_sz); i++) {
if (misa_extension_imp(valid_isa_order[i]))
out[pos++] = valid_isa_order[i];
}
if (pos < out_sz)
out[pos++] = '\0';
}
unsigned long csr_read_num(int csr_num)
{
unsigned long ret = 0;