[csrng/sec] create fields to enable functions
Use a field instead of a single bit to enable functions is considered more secure.
Signed-off-by: Mark Branstad <mark.branstad@wdc.com>
diff --git a/hw/ip/csrng/data/csrng.hjson b/hw/ip/csrng/data/csrng.hjson
index 5ead4b8..98a13c3 100644
--- a/hw/ip/csrng/data/csrng.hjson
+++ b/hw/ip/csrng/data/csrng.hjson
@@ -86,9 +86,8 @@
registers: [
{ name: "REGWEN",
desc: "Register write enable for all control registers",
- swaccess: "ro", // lock is managed by HW
- hwaccess: "hwo",
- hwext: "true",
+ swaccess: "rw0c",
+ hwaccess: "none",
fields: [
{
bits: "0",
@@ -103,16 +102,27 @@
desc: "Control register",
swaccess: "rw",
hwaccess: "hro",
+ regwen: "REGWEN",
+ tags: [// Exclude from writes to these bits since hardware actions will start.
+ "excl:CsrAllTests:CsrExclWrite"]
fields: [
{
- bits: "0",
+ bits: "3:0",
name: "ENABLE",
desc: '''
- Setting this bit will enable the CSRNG module. The application interface for software
- (register based) will be enabled only if the respective efuse input is enabled.
+ Setting this field to 0xA will enable the CSRNG module.
'''
- tags: [// Exclude from writes to these bits.
- "excl:CsrAllTests:CsrExclWrite"]
+ resval: "0x5"
+ },
+ {
+ bits: "7:4",
+ name: "SW_APP_ENABLE",
+ desc: '''
+ Setting this field to 0xA will enable reading from the GENBITS register.
+ This application interface for software (register based) will be enabled
+ only if the efuse_sw_app_enable input is set.
+ '''
+ resval: "0x5"
},
]
},
